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Molecular Profiling of Innate Immune Response Mechanisms in Ventilator-associated Pneumonia [Research]

Ventilator-associated pneumonia (VAP) is a common hospital-acquired infection, leading to high morbidity and mortality. Currently, bronchoalveolar lavage (BAL) is used in hospitals for VAP diagnosis and guiding treatment options. Although BAL collection procedures are invasive, alternatives such as endotracheal aspirates (ETA) may be of diagnostic value, however, their use has not been thoroughly explored. Longitudinal ETA and BAL were collected from 16 intubated patients up to 15 days, of which 11 developed VAP. We conducted a comprehensive LC–MS/MS based proteome and metabolome characterization of longitudinal ETA and BAL to detect host and pathogen responses to VAP infection. We discovered a diverse ETA proteome of the upper airways reflective of a rich and dynamic host-microbe interface. Prior to VAP diagnosis by microbial cultures from BAL, patient ETA presented characteristic signatures of reactive oxygen species and neutrophil degranulation, indicative of neutrophil mediated pathogen processing as a key host response to the VAP infection. Along with an increase in amino acids, this is suggestive of extracellular membrane degradation resulting from proteolytic activity of neutrophil proteases. The metaproteome approach successfully allowed simultaneous detection of pathogen peptides in patients' ETA, which may have potential use in diagnosis. Our findings suggest that ETA may facilitate early mechanistic insights into host-pathogen interactions associated with VAP infection and therefore provide its diagnosis and treatment.




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Agonists of Orally Expressed TRP Channels Stimulate Salivary Secretion and Modify the Salivary Proteome [Research]

Natural compounds that can stimulate salivary secretion are of interest in developing treatments for xerostomia, the perception of a dry mouth, that affects between 10 and 30% of the adult and elderly population. Chemesthetic transient receptor potential (TRP) channels are expressed in the surface of the oral mucosa. The TRPV1 agonists capsaicin and piperine have been shown to increase salivary flow when introduced into the oral cavity but the sialogogic properties of other TRP channel agonists have not been investigated. In this study we have determined the influence of different TRP channel agonists on the flow and protein composition of saliva. Mouth rinsing with the TRPV1 agonist nonivamide or menthol, a TRPM8 agonist, increased whole mouth saliva (WMS) flow and total protein secretion compared with unstimulated saliva, the vehicle control mouth rinse or cinnamaldehyde, a TRPA1 agonist. Nonivamide also increased the flow of labial minor gland saliva but parotid saliva flow rate was not increased. The influence of TRP channel agonists on the composition and function of the salivary proteome was investigated using a multi-batch quantitative MS method novel to salivary proteomics. Inter-personal and inter-mouth rinse variation was observed in the secreted proteomes and, using a novel bioinformatics method, inter-day variation was identified with some of the mouth rinses. Significant changes in specific salivary proteins were identified after all mouth rinses. In the case of nonivamide, these changes were attributed to functional shifts in the WMS secreted, primarily the over representation of salivary and nonsalivary cystatins which was confirmed by immunoassay. This study provides new evidence of the impact of TRP channel agonists on the salivary proteome and the stimulation of salivary secretion by a TRPM8 channel agonist, which suggests that TRP channel agonists are potential candidates for developing treatments for sufferers of xerostomia.




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Novel Proteome Extraction Method Illustrates a Conserved Immunological Signature of MSI-H Colorectal Tumors [Research]

Using a simple, environment friendly proteome extraction (TOP), we were able to optimize the analysis of clinical samples. Using our TOP method we analyzed a clinical cohort of microsatellite stable (MSS) and unstable (MSI-H) colorectal carcinoma (CRC). We identified a tumor cell specific, STAT1-centered, immune signature expressed by the MSI-H tumor cells. We then showed that long, but not short, exposure to Interferon- induces a similar signature in vitro. We identified 10 different temporal protein expression patterns, classifying the Interferon- protein temporal regulation in CRC. Our data sheds light on the changes that tumor cells undergo under long-term immunological pressure in vivo, the importance of STAT proteins in specific biological scenarios. The data generated could help find novel clinical biomarkers and therapeutic approaches.




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Sialylation of Asparagine 612 Inhibits Aconitase Activity during Mouse Sperm Capacitation; a Possible Mechanism for the Switch from Oxidative Phosphorylation to Glycolysis [Research]

After ejaculation, mammalian spermatozoa must undergo a process known as capacitation in order to successfully fertilize the oocyte. Several post-translational modifications occur during capacitation, including sialylation, which despite being limited to a few proteins, seems to be essential for proper sperm-oocyte interaction. Regardless of its importance, to date, no single study has ever identified nor quantified which glycoproteins bearing terminal sialic acid (Sia) are altered during capacitation. Here we characterize sialylation during mouse sperm capacitation. Using tandem MS coupled with liquid chromatography (LC–MS/MS), we found 142 nonreductant peptides, with 9 of them showing potential modifications on their sialylated oligosaccharides during capacitation. As such, N-linked sialoglycopeptides from C4b-binding protein, endothelial lipase (EL), serine proteases 39 and 52, testis-expressed protein 101 and zonadhesin were reduced following capacitation. In contrast, mitochondrial aconitate hydratase (aconitase; ACO2), a TCA cycle enzyme, was the only protein to show an increase in Sia content during capacitation. Interestingly, although the loss of Sia within EL (N62) was accompanied by a reduction in its phospholipase A1 activity, a decrease in the activity of ACO2 (i.e. stereospecific isomerization of citrate to isocitrate) occurred when sialylation increased (N612). The latter was confirmed by N612D recombinant protein tagged with both His and GFP. The replacement of Sia for the negatively charged Aspartic acid in the N612D mutant caused complete loss of aconitase activity compared with the WT. Computer modeling show that N612 sits atop the catalytic site of ACO2. The introduction of Sia causes a large conformational change in the alpha helix, essentially, distorting the active site, leading to complete loss of function. These findings suggest that the switch from oxidative phosphorylation, over to glycolysis that occurs during capacitation may come about through sialylation of ACO2.




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Asparagine Hydroxylation is a Reversible Post-translational Modification [Research]

Amino acid hydroxylation is a common post-translational modification, which generally regulates protein interactions or adds a functional group that can be further modified. Such hydroxylation is currently considered irreversible, necessitating the degradation and re-synthesis of the entire protein to reset the modification. Here we present evidence that the cellular machinery can reverse FIH-mediated asparagine hydroxylation on intact proteins. These data suggest that asparagine hydroxylation is a flexible and dynamic post-translational modification akin to modifications involved in regulating signaling networks, such as phosphorylation, methylation and ubiquitylation.




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Novel Proteomic Profiling of Epididymal Extracellular Vesicles in the Domestic Cat Reveals Proteins Related to Sequential Sperm Maturation with Differences Observed between Normospermic and Teratospermic Individuals [Research]

Extracellular vesicles (EVs) secreted by the epididymal epithelium transfer to spermatozoa key proteins that are essential in promoting motility and subsequent fertilization success. Using the domestic cat model, the objectives were to (1) characterize and compare protein content of EVs between segments of the epididymis, and (2) compare EV protein compositions between normo- and teratospermic individuals (producing >60% of abnormal spermatozoa). Epididymal EVs from adult cats were isolated and assessed via liquid chromatography tandem MS. Both male types shared 3008 proteins in total, with 98 and 20 EV proteins unique to normospermic and teratospermic males, respectively. Expression levels of several proteins changed between epididymal segments in both male types. Several proteins in both groups were related to sperm motility (e.g. hexokinase 1, adenylate kinase isoenzyme) and zona pellucida or oolemma binding (e.g. disintegrin and metalloproteinase domain proteins, zona binding proteins 1 and 2). Interestingly, seven cauda-derived EV proteins trended downward in teratospermic compared with normospermic males, which may relate to poor sperm quality. Collective results revealed, for the first time, EV proteins related to sequential sperm maturation with differences observed between normospermic and teratospermic individuals.




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Kinome Profiling of Primary Endometrial Tumors Using Multiplexed Inhibitor Beads and Mass Spectrometry Identifies SRPK1 as Candidate Therapeutic Target [Research]

Endometrial carcinoma (EC) is the most common gynecologic malignancy in the United States, with limited effective targeted therapies. Endometrial tumors exhibit frequent alterations in protein kinases, yet only a small fraction of the kinome has been therapeutically explored. To identify kinase therapeutic avenues for EC, we profiled the kinome of endometrial tumors and normal endometrial tissues using Multiplexed Inhibitor Beads and Mass Spectrometry (MIB-MS). Our proteomics analysis identified a network of kinases overexpressed in tumors, including Serine/Arginine-Rich Splicing Factor Kinase 1 (SRPK1). Immunohistochemical (IHC) analysis of endometrial tumors confirmed MIB-MS findings and showed SRPK1 protein levels were highly expressed in endometrioid and uterine serous cancer (USC) histological subtypes. Moreover, querying large-scale genomics studies of EC tumors revealed high expression of SRPK1 correlated with poor survival. Loss-of-function studies targeting SRPK1 in an established USC cell line demonstrated SRPK1 was integral for RNA splicing, as well as cell cycle progression and survival under nutrient deficient conditions. Profiling of USC cells identified a compensatory response to SRPK1 inhibition that involved EGFR and the up-regulation of IGF1R and downstream AKT signaling. Co-targeting SRPK1 and EGFR or IGF1R synergistically enhanced growth inhibition in serous and endometrioid cell lines, representing a promising combination therapy for EC.




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Mutation-independent Proteomic Signatures of Pathological Progression in Murine Models of Duchenne Muscular Dystrophy [Research]

The absence of the dystrophin protein in Duchenne muscular dystrophy (DMD) results in myofiber fragility and a plethora of downstream secondary pathologies. Although a variety of experimental therapies are in development, achieving effective treatments for DMD remains exceptionally challenging, not least because the pathological consequences of dystrophin loss are incompletely understood. Here we have performed proteome profiling in tibialis anterior muscles from two murine DMD models (mdx and mdx52) at three ages (8, 16, and 80 weeks of age), all n = 3. High-resolution isoelectric focusing liquid chromatography-tandem MS (HiRIEF-LC–MS/MS) was used to quantify the expression of 4974 proteins across all 27 samples. The two dystrophic models were found to be highly similar, whereas multiple proteins were differentially expressed relative to WT (C57BL/6) controls at each age. Furthermore, 1795 proteins were differentially expressed when samples were pooled across ages and dystrophic strains. These included numerous proteins associated with the extracellular matrix and muscle function that have not been reported previously. Pathway analysis revealed multiple perturbed pathways and predicted upstream regulators, which together are indicative of cross-talk between inflammatory, metabolic, and muscle growth pathways (e.g. TNF, INF, NF-B, SIRT1, AMPK, PGC-1α, PPARs, ILK, and AKT/PI3K). Upregulation of CAV3, MVP and PAK1 protein expression was validated in dystrophic muscle by Western blot. Furthermore, MVP was upregulated during, but not required for, the differentiation of C2C12 myoblasts suggesting that this protein may affect muscle regeneration. This study provides novel insights into mutation-independent proteomic signatures characteristic of the dystrophic phenotype and its progression with aging.




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A Comprehensive Gender-related Secretome of Plasmodium berghei Sexual Stages [Research]

Plasmodium, the malaria parasite, undergoes a complex life cycle alternating between a vertebrate host and a mosquito vector of the genus Anopheles. In red blood cells of the vertebrate host, Plasmodium multiplies asexually or differentiates into gamete precursors, the male and female gametocytes, responsible for parasite transmission. Sexual stage maturation occurs in the midgut of the mosquito vector, where male and female gametes egress from the host erythrocytes to fuse and form a zygote. Gamete egress entails the successive rupture of two membranes surrounding the parasite, the parasitophorous vacuole membrane and the erythrocyte plasma membrane. In this study, we used the rodent model parasite Plasmodium berghei to design a label-free quantitative proteomic approach aimed at identifying gender-related proteins differentially released/secreted by purified mature gametocytes when activated to form gametes. We compared the abundance of molecules secreted by wild type gametocytes of both genders with that of a transgenic line defective in male gamete maturation and egress. This enabled us to provide a comprehensive data set of egress-related molecules and their gender specificity. Using specific antibodies, we validated eleven candidate molecules, predicted as either gender-specific or common to both male and female gametocytes. All of them localize to punctuate, vesicle-like structures that relocate to cell periphery upon activation, but only three of them localize to the gametocyte-specific secretory vesicles named osmiophilic bodies. Our results confirm that the egress process involves a tightly coordinated secretory apparatus that includes different types of vesicles and may put the basis for functional studies aimed at designing novel transmission-blocking molecules.




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A Mouse Brain-based Multi-omics Integrative Approach Reveals Potential Blood Biomarkers for Ischemic Stroke [Research]

Stroke remains a leading cause of death and disability worldwide. Despite continuous advances, the identification of key molecular signatures in the hyper-acute phase of ischemic stroke is still a primary interest for translational research on stroke diagnosis, prognosis, and treatment. Data integration from high-throughput -omics techniques has become crucial to unraveling key interactions among different molecular elements in complex biological contexts, such as ischemic stroke. Thus, we used advanced data integration methods for a multi-level joint analysis of transcriptomics and proteomics data sets obtained from mouse brains at 2 h after cerebral ischemia. By modeling net-like correlation structures, we identified an integrated network of genes and proteins that are differentially expressed at a very early stage after stroke. We validated 10 of these deregulated elements in acute stroke, and changes in their expression pattern over time after cerebral ischemia were described. Of these, CLDN20, GADD45G, RGS2, BAG5, and CTNND2 were next evaluated as blood biomarkers of cerebral ischemia in mice and human blood samples, which were obtained from stroke patients and patients presenting stroke-mimicking conditions. Our findings indicate that CTNND2 levels in blood might potentially be useful for distinguishing ischemic strokes from stroke-mimicking conditions in the hyper-acute phase of the disease. Furthermore, circulating GADD45G content within the first 6 h after stroke could also play a key role in predicting poor outcomes in stroke patients. For the first time, we have used an integrative biostatistical approach to elucidate key molecules in the initial stages of stroke pathophysiology and highlight new notable molecules that might be further considered as blood biomarkers of ischemic stroke.




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Metabolic profiling in colorectal cancer reveals signature metabolic shifts during tumorigenesis [13. Other]

Colorectal cancer (CRC) arises as the consequence of progressive changes from normal epithelial cells through polyp to tumor, and thus is an useful model for studying metabolic shift. In the present study, we studied the metabolomic profiles using high analyte specific gas chromatography/mass spectrometry (GC/MS) and liquid chromatography tandem mass spectrometry (LC/MS/MS) to attain a systems-level view of the shift in metabolism in cells progressing along the path to CRC. Colonic tissues including tumor, polyps and adjacent matched normal mucosa from 26 patients with sporadic CRC from freshly isolated resections were used for this study. The metabolic profiles were obtained using GC/MS and LC/MS/MS. Our data suggest there was a distinct profile change of a wide range of metabolites from mucosa to tumor tissues. Various amino acids and lipids in the polyps and tumors were elevated, suggesting higher energy needs for increased cellular proliferation. In contrast, significant depletion of glucose and inositol in polyps revealed that glycolysis may be critical in early tumorigenesis. In addition, the accumulation of hypoxanthine and xanthine, and the decrease of uric acid concentration, suggest that the purine biosynthesis pathway could have been substituted by the salvage pathway in CRC. Further, there was a step-wise reduction of deoxycholic acid concentration from mucosa to tumors. It appears that to gain a growth advantage, cancer cells may adopt alternate metabolic pathways in tumorigenesis and this flexibility allows them to adapt and thrive in harsh environment.




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Bayesian Proteoform Modeling Improves Protein Quantification of Global Proteomic Measurements [Technology]

As the capability of mass spectrometry-based proteomics has matured, tens of thousands of peptides can be measured simultaneously, which has the benefit of offering a systems view of protein expression. However, a major challenge is that with an increase in throughput, protein quantification estimation from the native measured peptides has become a computational task. A limitation to existing computationally-driven protein quantification methods is that most ignore protein variation, such as alternate splicing of the RNA transcript and post-translational modifications or other possible proteoforms, which will affect a significant fraction of the proteome. The consequence of this assumption is that statistical inference at the protein level, and consequently downstream analyses, such as network and pathway modeling, have only limited power for biomarker discovery. Here, we describe a Bayesian model (BP-Quant) that uses statistically derived peptides signatures to identify peptides that are outside the dominant pattern, or the existence of multiple over-expressed patterns to improve relative protein abundance estimates. It is a research-driven approach that utilizes the objectives of the experiment, defined in the context of a standard statistical hypothesis, to identify a set of peptides exhibiting similar statistical behavior relating to a protein. This approach infers that changes in relative protein abundance can be used as a surrogate for changes in function, without necessarily taking into account the effect of differential post-translational modifications, processing, or splicing in altering protein function. We verify the approach using a dilution study from mouse plasma samples and demonstrate that BP-Quant achieves similar accuracy as the current state-of-the-art methods at proteoform identification with significantly better specificity. BP-Quant is available as a MatLab ® and R packages at https://github.com/PNNL-Comp-Mass-Spec/BP-Quant.




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The Proteomics of Networks and Pathways: A Movie is Worth a Thousand Pictures [Editorial]

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Quantitative profiling of protein tyrosine kinases in human cancer cell lines by multiplexed parallel reaction monitoring assays [Technology]

Protein tyrosine kinases (PTKs) play key roles in cellular signal transduction, cell cycle regulation, cell division, and cell differentiation. Dysregulation of PTK-activated pathways, often by receptor overexpression, gene amplification, or genetic mutation, is a causal factor underlying numerous cancers. In this study, we have developed a parallel reaction monitoring (PRM)-based assay for quantitative profiling of 83 PTKs. The assay detects 308 proteotypic peptides from 54 receptor tyrosine kinases and 29 nonreceptor tyrosine kinases in a single run. Quantitative comparisons were based on the labeled reference peptide method. We implemented the assay in four cell models: 1) a comparison of proliferating versus epidermal growth factor (EGF)-stimulated A431 cells, 2) a comparison of SW480Null (mutant APC) and SW480APC (APC restored) colon tumor cell lines, and 3) a comparison of 10 colorectal cancer cell lines with different genomic abnormalities, and 4) lung cancer cell lines with either susceptibility (11-18) or acquired resistance (11-18R) to the epidermal growth factor receptor tyrosine kinase inhibitor erlotinib. We observed distinct PTK expression changes that were induced by stimuli, genomic features or drug resistance, which were consistent with previous reports. However, most of the measured expression differences were novel observations. For example, acquired resistance to erlotinib in the 11-18 cell model was associated not only with previously reported upregulation of MET, but also with upregulation of FLK2 and downregulation of LYN and PTK7. Immunoblot analyses and shotgun proteomics data were highly consistent with PRM data. Multiplexed PRM assays provide a targeted, systems-level profiling approach to evaluate cancer-related proteotypes and adaptations. Data are available through Proteome eXchange Accession PXD002706.




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Translating Divergent Environmental Stresses into a Common Proteome Response through Hik33 in a Model Cyanobacterium [Research]

The histidine kinase Hik33 plays important roles in mediating cyanobacterial response to divergent types of abiotic stresses including cold, salt, high light (HL), and osmotic stresses. However, how these functions are regulated by Hik33 remains to be addressed. Using a hik33-deficient strain (hik33) of Synechocystis sp. PCC 6803 (Synechocystis) and quantitative proteomics, we found that Hik33 depletion induces differential protein expression highly similar to that induced by divergent types of stresses. This typically includes downregulation of proteins in photosynthesis and carbon assimilation that are necessary for cell propagation, and upregulation of heat shock proteins, chaperons, and proteases that are important for cell survival. This observation indicates that depletion of Hik33 alone mimics divergent types of abiotic stresses, and that Hik33 could be important for preventing abnormal stress response in the normal condition. Moreover, we found the majority of proteins of plasmid origin were significantly upregulated in hik33, though their biological significance remains to be addressed. Together, the systematically characterized Hik33-regulated cyanobacterial proteome, which is largely involved in stress responses, builds the molecular basis for Hik33 as a general regulator of stress responses.




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Recent advances in software tools for more generic and precise intact glycopeptide analysis [Review]

Intact glycopeptide identification has long been known as a key and challenging barrier to the comprehensive and accurate understanding the role of glycosylation in an organism. Intact glycopeptide analysis is a blossoming field that has received increasing attention in recent years. Mass spectrometry (MS)-based strategies and relative software tools are major drivers that have greatly facilitated the analysis of intact glycopeptides, particularly intact N-glycopeptides. This manuscript provides a systematic review of the intact glycopeptide identification process using mass spectrometry data generated in shotgun proteomic experiments, which typically focus on N-glycopeptide analysis. Particular attention is paid to the software tools that have been recently developed in the last decade for the interpretation and quality control of glycopeptide spectra acquired using different MS strategies. The review also provides information about the characteristics and applications of these software tools, discusses their advantages and disadvantages, and concludes with a discussion of outstanding tools.




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Methods for Enrichment and Assignment of N-Acetylglucosamine Modification Sites [Review]

O-GlcNAcylation, the addition of a single N-acetylglucosamine residue to serine and threonine residues of cytoplasmic, nuclear, or mitochondrial proteins, is a widespread regulatory post-translational modification. It is involved in response to nutritional status and stress and its dysregulation is associated with diseases ranging from Alzheimer’s to diabetes.  While the modification was first detected over thirty-five years ago, research into the function of O-GlcNAcylation has accelerated dramatically in the last ten years due to the development of new enrichment and mass spectrometry techniques that facilitate its analysis.  This article summarizes methods for O-GlcNAc enrichment, key mass spectrometry instrumentation advancements, particularly those that allow modification site localization, and software tools that allow analysis of data from O-GlcNAc modified peptides.




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CIITA-transduced glioblastoma cells uncover a rich repertoire of clinically relevant tumor-associated HLA-II antigens [Research]

CD4+ T cell responses are crucial for inducing and maintaining effective anti-cancer immunity, and the identification of human leukocyte antigen class II (HLA-II) cancer-specific epitopes is key to the development of potent cancer immunotherapies. In many tumor types, and especially in glioblastoma (GBM), HLA-II complexes are hardly ever naturally expressed. Hence, little is known about immunogenic HLA-II epitopes in GBM. With stable expression of the class II major histocompatibility complex transactivator (CIITA) coupled to a detailed and sensitive mass spectrometry based immunopeptidomics analysis, we here uncovered a remarkable breadth of the HLA-ligandome in HROG02, HROG17 and RA GBM cell lines. The effect of CIITA expression on the induction of the HLA-II presentation machinery was striking in each of the three cell lines, and it was significantly higher compared to interferon gamma (IFN) treatment. In total, we identified 16,123 unique HLA-I peptides and 32,690 unique HLA-II peptides. In order to genuinely define the identified peptides as true HLA ligands, we carefully characterized their association with the different HLA allotypes. In addition, we identified 138 and 279 HLA-I and HLA-II ligands, respectively, most of which are novel in GBM, derived from known GBM-associated tumor-antigens that have been used as source proteins for a variety of GBM vaccines. Our data further indicate that CIITA-expressing GBM cells acquired an antigen presenting cell-like phenotype as we found that they directly present external proteins as HLA-II ligands. Not only that CIITA-expressing GBM cells are attractive models for antigen discovery endeavors, but also such engineered cells have great therapeutic potential through massive presentation of a diverse antigenic repertoire.




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Systematic Proteome and Lysine Succinylome Analysis Reveals the Enhanced Cell Migration by Hyposuccinylation in Esophageal Squamous Cell Cancer [Research]

Esophageal squamous cell cancer (ESCC) is an aggressive malignancy with poor therapeutic outcomes. However, the alterations in proteins and post-translational modifications (PTMs) leading to the pathogenesis of ESCC remains unclear. Here, we provide the comprehensive characterization of the proteome, phosphorylome, lysine acetylome and succinylome for ESCC and matched control cells using quantitative proteomic approach. We identify abnormal protein and post-translational modification (PTM) pathways, including significantly downregulated lysine succinylation sites in cancer cells. Focusing on hyposuccinylation, we reveal that this altered PTM was enriched on enzymes of metabolic pathways inextricably linked with cancer metabolism. Importantly, ESCC malignant behaviors such as cell migration are inhibited once the level of succinylation was restored in vitro or in vivo. This effect was further verified by mutations to disrupt succinylation sites in candidate proteins. Meanwhile, we found that succinylation has a negative regulatory effect on histone methylation to promote cancer migration. Finally, hyposuccinylation is confirmed in primary ESCC specimens. Our findings together demonstrate that lysine succinylation may alter ESCC metabolism and migration, providing new insights into the functional significance of PTM in cancer biology.




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N-glycomic signature of stage II colorectal cancer and its association with the tumor microenvironment [Research]

The choice for adjuvant chemotherapy in stage II colorectal cancer (CRC) is controversial as many patients are cured by surgery alone and it is difficult to identify patients with high-risk of recurrence of the disease. There is a need for better stratification of this group of patients. Mass spectrometry imaging could identify patients at risk. We report here the N-glycosylation signatures of the different cell populations in a group of stage II CRC tissue samples. The cancer cells, compared to normal epithelial cells, have increased levels of sialylation and high-mannose glycans, as well as decreased levels of fucosylation and highly branched N-glycans. When looking at the interface between cancer and its microenvironment, it seems that the cancer N-glycosylation signature spreads into the surrounding stroma at the invasive front of the tumor. This finding was more outspoken in patients with a worse outcome within this sample group.




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Isolation of acetylated and unmodified protein N-terminal peptides by strong cation exchange chromatographic separation of TrypN-digested peptides [Technological Innovation and Resources]

We developed a simple and rapid method to enrich protein N-terminal peptides, in which the protease TrypN is first employed to generate protein N-terminal peptides without Lys or Arg and internal peptides with two positive charges at their N-termini, and then the N-terminal peptides with or without N-acetylation are separated from the internal peptides by strong cation exchange chromatography according to a retention model based on the charge/orientation of peptides. This approach was applied to 20 μg of human HEK293T cell lysate proteins to profile the N-terminal proteome. On average, 1,550 acetylated and 200 unmodified protein N-terminal peptides were successfully identified in a single LC/MS/MS run with less than 3% contamination with internal peptides, even when we accepted only canonical protein N-termini registered in the Swiss-Prot database. Since this method involves only two steps, protein digestion and chromatographic separation, without the need for tedious chemical reactions, it should be useful for comprehensive profiling of protein N-termini, including proteoforms with neo-N-termini.




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Protein modification characteristics of the malaria parasite Plasmodium falciparum and the infected erythrocytes [Research]

Malaria elimination is still pending on the development of novel tools that rely on a deep understanding of parasite biology. Proteins of all living cells undergo a myriad number of posttranslational modifications (PTMs) that are critical to multifarious life processes. An extensive proteome-wide dissection revealed a fine PTM map of most proteins in both Plasmodium falciparum, the causative agent of severe malaria, and the infected red blood cells. More than two-thirds of proteins of the parasite and its host cell underwent extensive and dynamic modification throughout the erythrocytic developmental stage. PTMs critically modulate the virulence factors involved in the host-parasite interaction and pathogenesis. Furthermore, P. falciparum stabilized the supporting proteins of erythrocyte origin by selective de-modification. Collectively, our multiple omic analyses, apart from having furthered a deep understanding of the systems biology of P. falciparum and malaria pathogenesis, provide a valuable resource for mining new antimalarial targets.




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Accelerating the field of epigenetic histone modification through mass spectrometry-based approaches [Review]

Histone post-translational modifications (PTMs) are one of the main mechanisms of epigenetic regulation. Dysregulation of histone PTMs leads to many human diseases, such as cancer. Due to its high-throughput, accuracy, and flexibility, mass spectrometry (MS) has emerged as a powerful tool in the epigenetic histone modification field, allowing the comprehensive and unbiased analysis of histone PTMs and chromatin-associated factors. Coupled with various techniques from molecular biology, biochemistry, chemical biology and biophysics, MS has been employed to characterize distinct aspects of histone PTMs in the epigenetic regulation of chromatin functions. In this review we will describe advancements in the field of MS that have facilitated the analysis of histone PTMs and chromatin biology.  




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Thyroglobulin interactome profiling defines altered proteostasis topology associated with thyroid dyshormonogenesis [Research]

Thyroglobulin (Tg) is a secreted iodoglycoprotein serving as the precursor for T3 and T4 hormones. Many characterized Tg gene mutations produce secretion-defective variants resulting in congenital hypothyroidism (CH). Tg processing and secretion is controlled by extensive interactions with chaperone, trafficking, and degradation factors comprising the secretory proteostasis network. While dependencies on individual proteostasis network components are known, the integration of proteostasis pathways mediating Tg protein quality control and the molecular basis of mutant Tg misprocessing remain poorly understood. We employ a multiplexed quantitative affinity purification–mass spectrometry approach to define the Tg proteostasis interactome and changes between WT and several CH-variants. Mutant Tg processing is associated with common imbalances in proteostasis engagement including increased chaperoning, oxidative folding, and engagement by targeting factors for ER-associated degradation (ERAD). Furthermore, we reveal mutation-specific changes in engagement with N-glycosylation components, suggesting distinct requirements for one Tg variant on dual engagement of both oligosaccharyltransferase complex isoforms for degradation. Modulating dysregulated proteostasis components and pathways may serve as a therapeutic strategy to restore Tg secretion and thyroid hormone biosynthesis.




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Prediction and validation of mouse meiosis-essential genes based on spermatogenesis proteome dynamics [Research]

The molecular mechanism associated with mammalian meiosis has yet to be fully explored, and one of the main reasons for this lack of exploration is that some meiosis-essential genes are still unknown. The profiling of gene expression during spermatogenesis has been performed in previous studies, yet few studies have aimed to find new functional genes. Since there is a huge gap between the number of genes that are able to be quantified and the number of genes that can be characterized by phenotype screening in one assay, an efficient method to rank quantified genes according to phenotypic relevance is of great importance. We proposed to rank genes by the probability of their function in mammalian meiosis based on global protein abundance using machine learning. Here, nine types of germ cells focusing on continual substages of meiosis prophase I were isolated, and the corresponding proteomes were quantified by high-resolution mass spectrometry. By combining meiotic labels annotated from the MGI mouse knockout database and the spermatogenesis proteomics dataset, a supervised machine learning package, FuncProFinder, was developed to rank meiosis-essential candidates. Of the candidates whose functions were unannotated, four of ten genes with the top prediction scores, Zcwpw1, Tesmin, 1700102P08Rik and Kctd19, were validated as meiosis-essential genes by knockout mouse models. Therefore,  mammalian meiosis-essential genes could be efficiently predicted based on the protein abundance dataset, which provides a paradigm for other functional gene mining from a related abundance dataset.




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PTM-Shepherd: analysis and summarization of post-translational and chemical modifications from open search results [Technological Innovation and Resources]

Open searching has proven to be an effective strategy for identifying both known and unknown modifications in shotgun proteomics experiments. Rather than being limited to a small set of user-specified modifications, open searches identify peptides with any mass shift that may correspond to a single modification or a combination of several modifications. Here we present PTM-Shepherd, a bioinformatics tool that automates characterization of PTM profiles detected in open searches based on attributes such as amino acid localization, fragmentation spectra similarity, retention time shifts, and relative modification rates. PTM-Shepherd can also perform multi-experiment comparisons for studying changes in modification profiles, e.g. in data generated in different laboratories or under different conditions. We demonstrate how PTM-Shepherd improves the analysis of data from formalin-fixed paraffin-embedded samples, detects extreme underalkylation of cysteine in some datasets, discovers an artefactual modification introduced during peptide synthesis, and uncovers site-specific biases in sample preparation artifacts in a multi-center proteomics profiling study.




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CMMB (Carboxylate Modified Magnetic Bead) -based isopropanol gradient peptide fractionation (CIF) enables rapid and robust off-line peptide mixture fractionation in bottom-up proteomics [Research]

Deep proteome coverage in bottom-up proteomics requires peptide-level fractionation to simplify the complex peptide mixture before analysis by tandem mass spectrometry. By decreasing the number of co-eluting precursor peptide ions, fractionation effectively reduces the complexity of the sample leading to higher sample coverage and reduced bias towards high abundance precursors that are preferentially identified in data-dependent acquisition strategies. To achieve this goal, we report a bead-based off-line peptide fractionation method termed CIF or Carboxylate modified magnetic bead-based isopropanol gradient peptide fractionation. CIF is an extension of the SP3 (single-pot solid-phase-enhanced sample preparation) strategy and provides an effective but complementary approach to other commonly used fractionation methods including strong cation exchange (SCX) and reversed phase (RP)-based chromatography. We demonstrate that CIF is an effective offline separation strategy capable of increasing the depth of peptide analyte coverage both when used alone or as a second dimension of peptide fractionation in conjunction with high pH RP. These features make it ideally suited for a wide range of proteomic applications including the affinity purification of low abundance bait proteins.




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Drones and the European Union: Prospects for a Common Future

Drones and the European Union: Prospects for a Common Future Research paper sysadmin 30 January 2018

The debate over the use of drones is an opportunity for states to identify elements of military practice that their publics find uncomfortable or troubling, and to explain these areas of military operations in context.

A Heron drone on the runway at the Castor military camp in Gao, Mali, on 19 May 2017. Photo: Getty Images.

Summary

  • The debate over the use of drones is an opportunity for states to identify elements of military practice that their publics find uncomfortable or troubling, and to explain these areas of military operations in context.
  • Countries would benefit from working together to identify accountability gaps arising from fundamental elements of military cooperation, including the role of intelligence transfers in joint operations, and the distribution of responsibility for lethal actions in the context of coalition operations.
  • Transparency in investigation procedures, as well as devoting sufficient resources towards ensuring that mistakes are identified, will improve the perception of drone use among domestic audiences.
  • Identifying and communicating common standards and practices of mitigating complicity should be a priority for countries to ensure that they do not unwittingly become complicit in unlawful lethal operations.
  • Although operational safety may hinder the ability of states to be completely transparent, understanding among the general public could be improved through the communication of policies and procedures regarding non-lethal assistance to partner states conducting lethal operations, both inside and outside the context of an armed conflict.




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Moscow Rules: What Drives Russia to Confront the West

Moscow Rules: What Drives Russia to Confront the West Book sysadmin 17 January 2019

Keir Giles surveys Russia’s history and the present day to explain why its current leadership feels it has no choice but to challenge and attack the West. Recognising and accepting that this will not change in the near future will help the West find a way of dealing with Russia without risking a deeper conflict.

This book is for anyone that cannot understand why Russia and its leaders behave as they do.

The relationship between Russia and the West is once again deep in crisis. A major reason is that Western leaders have too often believed or hoped that Russia sees the world as they do — but things look very different from Moscow. This book shows that efforts at engagement with Russia that do not take this into account are a key reason for repeated disappointment and crisis.

In confronting the West, Russia is implementing strategic and doctrinal approaches that have been consistent for centuries. The roots of current Russian behaviour and demands can be traced not just to the Soviet era, but back into Tsarist foreign and domestic policy, and further to the structure and rules of Russian society. But this also gives the US and the West pointers for how to behave — and how not to — in order to manage the challenge of Russia effectively, based on past experience of both successful and unsuccessful engagement with Moscow.

The book recognizes the reality of confrontation and provides an essential introduction to grasping why Russia sees it as inevitable. Consequently, it offers a basis for building a less crisis-prone relationship with Russia.

This book is part of the Insights series.

Praise for Moscow Rules

My only regret is that I did not have this book 35 years ago

Toomas Ilves, former President of Estonia

Should be required reading for all who deal with Western policy towards Russia

Roderic Lyne, former British Ambassador to Moscow

About the author

Keir Giles is a senior consulting fellow at Chatham House, the Royal Institute of International Affairs. He also works with the Conflict Studies Research Centre (CSRC), a group of subject matter experts in Eurasian security with a particular focus on the wide range of security challenges coming from Russia.

Purchase




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Moving Energy Initiative Learning Briefs

Moving Energy Initiative Learning Briefs Research paper sysadmin 29 March 2019

Drawing on experiences from Phase II of the MEI in Burkina Faso, Kenya and Jordan, these learning briefs highlight MEI’s approach to innovation, engagement with the private-sector and host communities, and gender-sensitive energy projects. The four learning papers are intended for practitioners and policymakers working in the humanitarian sector and host-country governments.

A shelf of energy appliances in a shop in Kakuma Town, Kenya. Photo credit: Gabriela Flores

Findings from Phase I of the Moving Energy Initiative (MEI) in 2015, published in the Chatham House research paper Heat, Light and Power for Refugees: Saving Lives, Reducing Costs, highlight the negative impacts of limited sustainable energy provision on the security of displaced populations. The paper also identified some of the challenges for energy programmes in this sector, such as the lack of robust data on energy access and the priorities of refugee populations.

In Phase II of the MEI, Practical Action led detailed research into the energy needs of refugees in Burkina Faso and Kenya. Chatham House analysed data on global refugee energy use in displacement contexts and produced an interactive map. Energy 4 Impact explored sustainable funding options, private-sector contract models and non-wood cooking concessions. The market development and low-carbon energy initiatives in Burkina Faso, Jordan and Kenya were managed by Practical Action and Energy 4 Impact, with the support of local partners. These partners represented the MEI at multiple conferences and events to share findings and advocate for the inclusion of displaced people in the sustainable energy agenda.

Drawing on experiences from Phase II of the MEI in Burkina Faso, Kenya and Jordan, these learning briefs highlight MEI’s approach to innovation, engagement with the private-sector and host communities, and gender-sensitive energy projects. The four learning papers are intended for practitioners and policymakers working in the humanitarian sector and host-country governments.




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Optimized incorporation of an unnatural fluorescent amino acid affords measurement of conformational dynamics governing high-fidelity DNA replication [DNA and Chromosomes]

DNA polymerase from bacteriophage T7 undergoes large, substrate-induced conformational changes that are thought to account for high replication fidelity, but prior studies were adversely affected by mutations required to construct a Cys-lite variant needed for site-specific fluorescence labeling. Here we have optimized the direct incorporation of a fluorescent un-natural amino acid, (7-hydroxy-4-coumarin-yl)-ethylglycine, using orthogonal amber suppression machinery in Escherichia coli. MS methods verify that the unnatural amino acid is only incorporated at one position with minimal background. We show that the single fluorophore provides a signal to detect nucleotide-induced conformational changes through equilibrium and stopped-flow kinetic measurements of correct nucleotide binding and incorporation. Pre-steady-state chemical quench methods show that the kinetics and fidelity of DNA replication catalyzed by the labeled enzyme are largely unaffected by the unnatural amino acid. These advances enable rigorous analysis to establish the kinetic and mechanistic basis for high-fidelity DNA replication.




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Kinetic investigation of the polymerase and exonuclease activities of human DNA polymerase ϵ holoenzyme [DNA and Chromosomes]

In eukaryotic DNA replication, DNA polymerase ε (Polε) is responsible for leading strand synthesis, whereas DNA polymerases α and δ synthesize the lagging strand. The human Polε (hPolε) holoenzyme is comprised of the catalytic p261 subunit and the noncatalytic p59, p17, and p12 small subunits. So far, the contribution of the noncatalytic subunits to hPolε function is not well understood. Using pre-steady-state kinetic methods, we established a minimal kinetic mechanism for DNA polymerization and editing catalyzed by the hPolε holoenzyme. Compared with the 140-kDa N-terminal catalytic fragment of p261 (p261N), which we kinetically characterized in our earlier studies, the presence of the p261 C-terminal domain (p261C) and the three small subunits increased the DNA binding affinity and the base substitution fidelity. Although the small subunits enhanced correct nucleotide incorporation efficiency, there was a wide range of rate constants when incorporating a correct nucleotide over a single-base mismatch. Surprisingly, the 3'→5' exonuclease activity of the hPolε holoenzyme was significantly slower than that of p261N when editing both matched and mismatched DNA substrates. This suggests that the presence of p261C and the three small subunits regulates the 3'→5' exonuclease activity of the hPolε holoenzyme. Together, the 3'→5' exonuclease activity and the variable mismatch extension activity modulate the overall fidelity of the hPolε holoenzyme by up to 3 orders of magnitude. Thus, the presence of p261C and the three noncatalytic subunits optimizes the dual enzymatic activities of the catalytic p261 subunit and makes the hPolε holoenzyme an efficient and faithful replicative DNA polymerase.




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A human cancer cell line initiates DNA replication normally in the absence of ORC5 and ORC2 proteins [DNA and Chromosomes]

The origin recognition complex (ORC), composed of six subunits, ORC1–6, binds to origins of replication as a ring-shaped heterohexameric ATPase that is believed to be essential to recruit and load MCM2–7, the minichromosome maintenance protein complex, around DNA and initiate DNA replication. We previously reported the creation of viable cancer cell lines that lacked detectable ORC1 or ORC2 protein without a reduction in the number of origins firing. Here, using CRISPR-Cas9–mediated mutations, we report that human HCT116 colon cancer cells also survive when ORC5 protein expression is abolished via a mutation in the initiator ATG of the ORC5 gene. Even if an internal methionine is used to produce an undetectable, N terminally deleted ORC5, the protein would lack 80% of the AAA+ ATPase domain, including the Walker A motif. The ORC5-depleted cells show normal chromatin binding of MCM2–7 and initiate replication from a similar number of origins as WT cells. In addition, we introduced a second mutation in ORC2 in the ORC5 mutant cells, rendering both ORC5 and ORC2 proteins undetectable in the same cells and destabilizing the ORC1, ORC3, and ORC4 proteins. Yet the double mutant cells grow, recruit MCM2–7 normally to chromatin, and initiate DNA replication with normal number of origins. Thus, in these selected cancer cells, either a crippled ORC lacking ORC2 and ORC5 and present at minimal levels on the chromatin can recruit and load enough MCM2–7 to initiate DNA replication, or human cell lines can sometimes recruit MCM2–7 to origins independent of ORC.




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Polymerase {gamma} efficiently replicates through many natural template barriers but stalls at the HSP1 quadruplex [Enzymology]

Faithful replication of the mitochondrial genome is carried out by a set of key nuclear-encoded proteins. DNA polymerase γ is a core component of the mtDNA replisome and the only replicative DNA polymerase localized to mitochondria. The asynchronous mechanism of mtDNA replication predicts that the replication machinery encounters dsDNA and unique physical barriers such as structured genes, G-quadruplexes, and other obstacles. In vitro experiments here provide evidence that the polymerase γ heterotrimer is well-adapted to efficiently synthesize DNA, despite the presence of many naturally occurring roadblocks. However, we identified a specific G-quadruplex–forming sequence at the heavy-strand promoter (HSP1) that has the potential to cause significant stalling of mtDNA replication. Furthermore, this structured region of DNA corresponds to the break site for a large (3,895 bp) deletion observed in mitochondrial disease patients. The presence of this deletion in humans correlates with UV exposure, and we have found that efficiency of polymerase γ DNA synthesis is reduced after this quadruplex is exposed to UV in vitro.




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Genetic evidence for the involvement of mismatch repair proteins, PMS2 and MLH3, in a late step of homologous recombination [Cell Biology]

Homologous recombination (HR) repairs DNA double-strand breaks using intact homologous sequences as template DNA. Broken DNA and intact homologous sequences form joint molecules (JMs), including Holliday junctions (HJs), as HR intermediates. HJs are resolved to form crossover and noncrossover products. A mismatch repair factor, MLH3 endonuclease, produces the majority of crossovers during meiotic HR, but it remains elusive whether mismatch repair factors promote HR in nonmeiotic cells. We disrupted genes encoding the MLH3 and PMS2 endonucleases in the human B cell line, TK6, generating null MLH3−/− and PMS2−/− mutant cells. We also inserted point mutations into the endonuclease motif of MLH3 and PMS2 genes, generating endonuclease death MLH3DN/DN and PMS2EK/EK cells. MLH3−/− and MLH3DN/DN cells showed a very similar phenotype, a 2.5-fold decrease in the frequency of heteroallelic HR-dependent repair of restriction enzyme–induced double-strand breaks. PMS2−/− and PMS2EK/EK cells showed a phenotype very similar to that of the MLH3 mutants. These data indicate that MLH3 and PMS2 promote HR as an endonuclease. The MLH3DN/DN and PMS2EK/EK mutations had an additive effect on the heteroallelic HR. MLH3DN/DN/PMS2EK/EK cells showed normal kinetics of γ-irradiation–induced Rad51 foci but a significant delay in the resolution of Rad51 foci and a 3-fold decrease in the number of cisplatin-induced sister chromatid exchanges. The ectopic expression of the Gen1 HJ re-solvase partially reversed the defective heteroallelic HR of MLH3DN/DN/PMS2EK/EK cells. Taken together, we propose that MLH3 and PMS2 promote HR as endonucleases, most likely by processing JMs in mammalian somatic cells.




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Phosphorylation of SMURF2 by ATM exerts a negative feedback control of DNA damage response [DNA and Chromosomes]

Timely repair of DNA double-strand breaks (DSBs) is essential to maintaining genomic integrity and preventing illnesses induced by genetic abnormalities. We previously demonstrated that the E3 ubiquitin ligase SMURF2 plays a critical tumor suppressing role via its interaction with RNF20 (ring finger protein 20) in shaping chromatin landscape and preserving genomic stability. However, the mechanism that mobilizes SMURF2 in response to DNA damage remains unclear. Using biochemical approaches and MS analysis, we show that upon the onset of the DNA-damage response, SMURF2 becomes phosphorylated at Ser384 by ataxia telangiectasia mutated (ATM) serine/threonine kinase, and this phosphorylation is required for its interaction with RNF20. We demonstrate that a SMURF2 mutant with an S384A substitution has reduced capacity to ubiquitinate RNF20 while promoting Smad3 ubiquitination unabatedly. More importantly, mouse embryonic fibroblasts expressing the SMURF2 S384A mutant show a weakened ability to sustain the DSB response compared with those expressing WT SMURF2 following etoposide treatment. These data indicate that SMURF2-mediated RNF20 ubiquitination and degradation controlled by ataxia telangiectasia mutated–induced phosphorylation at Ser384 constitutes a negative feedback loop that regulates DSB repair.




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Phillies land Realmuto for 3 players, int'l money

The Phillies acquired All-Star catcher J.T. Realmuto from the Marlins on Thursday for catcher Jorge Alfaro, right-hander Sixto Sanchez, left-hander Will Stewart and $250,000 in international bonus slot money, the latest move in a busy and ambitious offseason for a team eager to return to the postseason.




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Manny? Harper? Klentak satisfied but monitoring

General Manager Matt Klentak discussed the Phillies' offseason in a press conference on Thursday in Clearwater, Fla. The Phillies remain in contact with the agents for Bryce Harper and Manny Machado. The belief is that the front office still prefers Machado over Harper because of Machado's combination of offense and defense.




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Leaner Herrera more mature after tough 2018

Odubel Herrera smiled and patted his stomach. The paunch that he carried into Spring Training 2018 is no longer there. Herrera has reported to camp leaner and, as he said Friday morning at Spectrum Field, motivated to bounce back from the worst season of his four-year career.




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Segura moving forward with contending Phillies

Jean Segura became one of the Phillies' most notable offseason acquisitions, a two-time All-Star expected to give the organization its best overall production at shortstop since Jimmy Rollins left town, in part because of a little brawl he had late last season with Mariners teammate Dee Gordon.




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Franco ignoring rumors, ready for 3B battle

Maikel Franco followed the endless and often mind-numbing speculation the past few months from the Dominican Republic. Franco knows that Manny Machado could show up at Spectrum Field at any moment. The Phillies entertained him at Citizens Bank Park just before Christmas. They have made him at least one contract offer. If the Phillies sign him, Franco also knows he could be traded.




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Kapler preaches focus at camp amid rumors

Phillies manager Gabe Kapler has a little advice for the players who could be impacted most if the team signs Bryce Harper or Manny Machado.




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Simmons ranks among game's best

MLB Network's countdown of baseball's best players at each position continued with the third installment of the "Top 10 Right Now!" series, featuring the game's top left and center fielders.




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Covid-19: NHS staff will be offered vaccine this autumn, but JCVI recommends more limited rollout




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Correction: Functional domain and motif analyses of androgen receptor coregulator ARA70 and its differential expression in prostate cancer. [Additions and Corrections]

VOLUME 279 (2004) PAGES 33438–33446For Fig. 1B, the second, third, and fifth panels were mistakenly duplicated during article preparation as no yeast colonies were observed in these conditions. The corrected images are presented in the revised Fig. 1B. This correction does not affect the results or conclusions of the work. The authors apologize for the error.jbc;295/50/17382/F1F1F1Figure 1B.




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Low molecular weight heparin does not prevent VTE after knee arthroscopy, studies show




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Afonso Dhlakama’s Death Changes the Calculation for Peace Prospects in Mozambique

Afonso Dhlakama’s Death Changes the Calculation for Peace Prospects in Mozambique Expert comment sysadmin 4 May 2018

If politicians continue to act in good faith, the death of the opposition leader may be a significant opportunity to finally draw a line under Mozambique’s long war.

Afonso Dhlakama addresses a crowd of supporters at a campaign rally in 2014. Photo: Getty Images.

The unexpected death of opposition and ex-rebel leader Afonso Dhlakama on 3 May is a game changer for Mozambique’s politics and an almost-completed peace process. The 65-year old Dhlakama, who died of a heart attack, had led Renamo for 38 years and had totally dominated his party. Dhlakama regularly boasted that he was Mozambique’s ‘father of democracy’, despite not allowing competition within his own party, and he leaves a legacy of more than 30 years of struggle, through both armed action and peaceful politics.

A long war

Originally Renamo had been a tool for the white minority regimes of Rhodesia and apartheid South Africa to challenge the socialist Frelimo political party that took power in Mozambique in 1975. But under Dhlakama’s command, by the late 1980s Renamo had become increasingly independent and rooted in Mozambique. After Renamo’s long war with Frelimo ground to a hurting stalemate, a transition led to Mozambique’s first multiparty elections in 1994, and the creation of a new joint army. A ‘pay and scatter’ programme successfully dispersed and reintegrated many thousands of ex-combatants.

But early post-election gains did not translate to lasting peace. Disarmament was a time-limited, technical process, and devoted declining resources and attention to clusters of ex-combatants that failed to disperse. In addition, Dhlakama was allowed to maintain an armed militia under the guise of a presidential guard.

Mounting economic inequality, notably in opposition strongholds such as central Mozambique, saw Renamo made political gains and Dhlakama nearly won the 1999 presidential elections. (Some believe he did.) The result focused Frelimo’s attention on the threat that Renamo posed and, ultimately, a strategy of pursuing total Frelimo domination across the country, culminating in a crushing Frelimo victory at the 2009 elections.

This humiliated and marginalized former Renamo rebels, resulting in Dhlakama ordering their return to targeted armed violence in 2013. Frelimo’s new leader, President Filipe Nyusi, took power in 2015 and sought direct dialogue with Dhlakama. Five rounds of internationally mediated peace talks took place from July to December. Finally, in late December 2016, Dhlakama announced a unilateral truce, which was extended twice and subsequently made indefinite.

New peace talks also started and, in August 2017 and February 2018, President Nyusi and Dhlakama showed the courage to meet in person, near Renamo’s base in central Mozambique, to build up mutual trust and discuss the details of the emerging peace deal – including the demobilization or integration into government security forces for Renamo’s now mostly middle-aged gunmen.

Dhlakama the ‘Big Man’

Dhlakama’s sudden death has fundamentally changed the negotiation dynamics. He never allowed for any serious succession planning, and ensured all key decisions were his and his alone. Renamo had already decided that he would be its presidential candidate for the 2019 national elections.

His party is significantly weakened by his death and unlikely able to fully recover – but needs to try and reach consensus quickly on a successor, as it will also compete in municipal elections in October and was expecting significant gains. There will be a number of contenders to succeed him including from the parliamentary wing, led by his niece Ivone Soares, its secretary general, Manuel Bissopo, and a few others.

But Renamo’s key leverage for now remains some 1,000 middle-aged gunmen in central Mozambique who have been stoically loyal to Dhlakama since the 1980s and who have little respect for the younger generation of professional politicians based in Maputo. Some may be bought off by government offers, others integrated into localised organized crime groups and others into internal Renamo sectarianism. The risk of fragmentation is real.

Renamo’s weakness could also embolden Frelimo hardliners to seek a return to unilateral domination of Mozambique’s political landscape, and to undermine the peace process. That would be a serious tactical mistake by Frelimo, as a lasting deal is close and the death of Dhlakama could actually assist in making this settlement lasting. Dhlakama was quixotic and prone to changing his mind, often influenced by the last person he spoke to – his death potentially introduces greater predictability in negotiations and in any post-deal implementation.

President Nyusi is clearly aware of this as he hailed on state television TVM that Dhlakama was ‘a citizen who has always worked for Mozambique’ and said he was distraught at the news of his death. He stated, ‘I hope that we as Mozambicans can continue to do everything so things do not go down.’ He also addressed Renamo’s support base by saying that ‘[Dhlakama] did everything so that there would be peace. The last time he spoke to me, he said he was not going to miss out anything in peace negotiations.’

Renamo’s gunmen are fatigued and want to retire with dignity but are vulnerable to manipulation and political miscalculation by Mozambican’s positioning politicians. International partners and investors can engage, by emphasizing that sustainable peace is the only pathway to poverty reduction and inclusive economic development.

This includes assisting development and reconciliation projects in areas impacted by the renewed conflict since 2013. Long-term investment for development in Renamo’s key constituencies could help avoid fragmentation at a critical time – faith groups and NGOs may also have a key role to play.

If Mozambique’s politicians continue to act in good faith, the death of Dhlakama may constitute a significant opportunity to finally draw a line under Mozambique’s long war.




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Hope, Peace and Reconciliation: Pope Francis in Mozambique

Hope, Peace and Reconciliation: Pope Francis in Mozambique Expert comment sysadmin 4 September 2019

A papal visit will highlight the importance of the recently signed peace agreement between the government and opposition.

Sales of papal-pictured capulanas have been brisk. Photo: Chatham House.

Pope Francis’ visit to Mozambique on 4–6 September comes at a critical political moment. The theme for the papal Africa trip (which also includes Madagascar and Mauritius) is ‘pilgrim of hope, peace and reconciliation’. This is especially relevant for Mozambique, as this is the first week of the official campaign for Mozambique’s sixth national elections on 15 October.

It is also the one-month anniversary of the Maputo Accords for Peace and Reconciliation between the government and the armed opposition, RENAMO (and the fifth anniversary of the previous such agreement in 2014).

What is unusual is that the pope accepted to visit Mozambique just after a peace accord and in the run-up to national elections. Something similar has happened only once, when Pope John Paul II visited Angola in June 1992 (following the Bicesse Accords) prior to the country’s first ever national elections in September. Unfortunately Pope John Paul’s preaching of reconciliation and pluralism failed and civil war resumed some months later, following rejection of the preliminary election results. Angola’s civil war only finally ended a decade later in 2002.

The last papal visit to Mozambique was also by Pope John Paul II in 1988, when civil war was still ongoing, and the country was still a single party state. Despite the war, massive congregations attended and RENAMO reached local ceasefires and agreements to maintain electricity supply to honour the visit. Some of the seeds for the Rome peace process were laid during this trip – especially as it also represented a formal reconciliation of FRELIMO, the ruling party, with the Catholic Church.

This papal visit to Mozambique is equally anticipated, as was highlighted several times during speeches at the 6 August peace agreement signing in Maputo. When I was in Maputo last month, sales of papal-pictured capulanas (a Mozambican sarong) were brisk and Mozambican television carried countdown clocks on many programmes for the touchdown of Pope Francis on national soil.

The Catholic Church has played an instrumental role in promoting peace in Mozambique over the years. The 1977–92 civil war ended through negotiations hosted at the Sant’ Egidio lay community in Rome, and the current Archbishop of Bologna, Dom Matteo Zuppi (who led the Sant’ Egido negotiations in 1992 and is soon to be made a cardinal) was an official witness to 6 August accords signing.

When targeted armed conflict resumed in 2013, faith groups once more re-engaged and in 2016 Sant’ Egidio once more co-led mediation efforts, less successfully than in 1991–92. Sant’ Egidio (including during a presidential visit to Rome in July) contributed to convincing the Vatican that this papal visit should occur before the October elections.

President Filipe Nyusi anxiously wanted this visit to occur before the elections. He is seeking re-election for his second and final term and a papal visit should help win some votes. His party, FRELIMO, is also worried about securing a majority in the national assembly, as it has been weakened by patchy delivery of services and ongoing high-level corruption scandals.

This year, President Nyusi’s priorities have been to show that he can attract international investment (such as Andarko’s recently announced final investment decision on its gas project), a peace agreement with RENAMO (the August agreements) and a papal visit, so a successful trip would complete his goals.

The pope’s ‘hope, peace and reconciliation’ message of his visit is important. Twice previously, the FRELIMO-led government and RENAMO have reached definitive agreements, in Rome (1992) and Maputo (2014), but failed to fully end bloodshed. This new August 2019 agreement is the third attempt, and if it is to last, it will require political goodwill, compromise and an acceptance of more inclusive national politics by both parties.

There are two immediate threats to this agreement. The first is the forthcoming 15 October elections and their conduct could make or break it. Accepting reconciliation and greater pluralism underpins this agreement, but RENAMO expects to increase its share of the parliamentary vote and win a majority in some provinces (and therefore indirectly elect their choice for governor).

A second threat is the ‘Military Junta’, a RENAMO splinter group that claims to be 500 strong, but probably accounts for 80 armed persons. It rejects the 6 August agreement and warns that it could disrupt the elections. This group has asked for mediation, and hopefully can be accommodated in a side deal to the main one agreed in August, which already provides for the reintegration of over 5,000 RENAMO supporters and combatants.

A recent Chatham House research paper on elite bargains in Mozambique concluded that the October elections will be the first immediate test of the August agreement. If the elections pass without significant electoral manipulation or violence and this August deal sticks on the third attempt, the domestic focus should then move onto poverty reduction, combating inequality, education and solving the new security crisis with Islamic militants in Cabo Delgado province.




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Can Liberation Movements Really Rid Southern Africa of Corruption?

Can Liberation Movements Really Rid Southern Africa of Corruption? Expert comment sysadmin 16 December 2019

Southern Africa’s national liberation movements have survived ‘end of decade’ elections across the region. Combating corruption has been at the heart of many of the campaigns, but the question is can they succeed?

Supporters of the Namibian incumbent president and ruling party South West Africa People’s Organisation (SWAPO) presidential candidate Hage Geingob cheer and dance. Photo by GIANLUIGI GUERCIA/AFP via Getty Images.

Swapo’s victory in Namibia two weeks ago was the last in a series of recent ‘end of decade’ elections that have returned dominant parties to power across Southern Africa. However, the “enduring appeal of liberation” is wearing thin.

Experiences across the region show that if governments are to deliver on their electoral promises, they must empower institutions, actively promote a culture of accountability and transparency within their party ranks and pursue economic reforms that untangle the web of party-state-business alliances. Such actions are critical for the survival of national liberation movements as the dominant force in the politics of Southern Africa – but will be difficult to implement.

Avoid political factionalism

South Africa, Botswana, Angola and Zimbabwe all saw new presidents take over just before elections. All used the rhetoric of anti-corruption to distance themselves from the tainted image of their predecessors. But acting on this requires a shift in mind-set in parties that have always preferred to deal with their problems behind closed doors. High profile adversaries from past regimes make tempting targets but could also drive party divisions.

In Angola, the transition of power was safeguarded by an agreement that former president José Eduardo dos Santos would be immune from prosecution. But this week his son faced corruption charges before the country’s supreme court, a high-profile example of a wave of anti-corruption cases across Southern Africa, driven by dominant parties wary of their future.

The allegations against José Filemino De Sousa Dos Santos, nickname ‘Zenu’, include a $500-million fraud involving the country’s central bank. Pressure is also mounting on Zenu’s sister Isabel — once prominent in Angola, she is now absent from public life.

Other leaders have had to tread more carefully. Immunity was a luxury Cyril Ramaphosa was neither willing nor politically able to grant Jacob Zuma in South Africa. Reliant on a few close allies at the top of the party, Ramaphosa lacks foot soldiers at the grassroots level, and his campaign against corruption within the ANC has faced persistent opposition.

Rebuilding institutions and empowering authorities takes time, and with few high-profile cases to point to, people are getting restless. This is also the case in Zimbabwe, where a worsening economic situation has left policy reformers politically isolated.

Party, state, and business

Long term incumbency has blurred the distinction between the party and the state. Liberation movements have created vast party-linked business empires. Political allegiance grants access to economic resources through appointments to lucrative positions in state-owned enterprises, preferential bids for tenders and licenses, and direct access to decision makers.

In Angola, this was fuelled by oil revenues. In South Africa, state capture flourished in an environment where the ANC and its constituent elements had significant power on the panels that chose leaders for state-owned enterprises (SOEs). In Namibia, an Icelandic fishing company paid backhanders to officials for fishing rights in what has become known as the ‘Fishrot’ scandal. Zanu-PF officials’ access to preferential foreign exchange rates present them with lucrative opportunities in Zimbabwe.

Ending this bureaucratic rent seeking goes beyond appointing ‘clean’ officials, which has been central to the anti-corruption campaigns in Angola and South Africa. Governments must also allow scrutiny of the state and empower those institutions designed for that role, such as the National Prosecuting Authority and the Public Protector in South Africa. Zimbabwe’s auditor general has published an in-depth report of the state of corruption in the country’s SOEs.

Companies must also be held to account for their role in aiding, and at worst directly benefitting, from state graft. International businesses have actively sought to benefit from corruption. They are now starting to face the consequences. A former Credit Suisse banker has pleaded guilty in the US over handling alleged kickbacks in Mozambique’s $2-billion “tuna bond” scandal. Global banks and consultancies continue to feel the squeeze for their complicity in state capture in South Africa.

Competition and pluralism

National liberation movements may only have a limited window within which to act. Across the region civil society campaigns and investigative journalists have shed light on some of the worst abuses of power. Anti-corruption campaigns are starting to bite. The state will continue to play a central role in Southern African economies, an important arbiter of economic transformation able to balance the region’s highly unequal and resource-dependent economies.

But opposition, civil society and the media are also critical for the progression towards democratic competition and pluralism in Southern Africa. Parliaments remain vital for holding rulers to account. Long used to unchallenged dominance, liberation movements have significant adjustments to make to rise to the challenge of a new era.

This article was originally published in the Mail and Guardian.




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Mozambique’s Peace and National Reconciliation Agreement: One Year On

Mozambique’s Peace and National Reconciliation Agreement: One Year On 6 August 2020 — 2:30PM TO 4:30PM Anonymous (not verified) 29 July 2020 Online

August 6, 2020 marks one year since the Peace and National Reconciliation Agreement was signed in Maputo. The agreement, signed by the President of Mozambique Filipe Nyusi and RENAMO leader Ossufo Momade, and witnessed by regional and international political and religious leaders, ended the return to conflict that started in 2013.

It also paved the way for Mozambique’s national elections in October 2019. Since the agreement, the Mozambique Liberation Front (FRELIMO) won a landslide victory in the elections, weakening RENAMO, and a splinter group has conducted targeted armed violence in Manica and Sofala provinces. Yet, the disarmament, demobilization, and reintegration (DDR) process has made progress.

At this event, senior figures reflect on the peace agreement and the key factors of its success. The event also draws upon insights from the authors of recent publications on the latest peace agreement in the context of longer term trends of democratization and peace-building in Mozambique.

A Chatham House Africa Programme research paper published in August 2019, Prospects for a Sustainable Elite Bargain in Mozambique: Third Time Lucky?, examined how the deal was achieved. The Portuguese version includes the full text of the peace accord. Read the research paper in Portuguese or English here.