proteins

Reconciling the regulatory role of Munc18 proteins in SNARE-complex assembly

Mammalian Munc18 proteins are essential for membrane fusion and human health. Here, we review the literature describing structural and in vitro data, and identify a possible explanation for the conflicting functional roles that have been reported.




proteins

Characterization of the Pseudomonas aeruginosa T6SS PldB immunity proteins PA5086, PA5087 and PA5088 explains a novel stockpiling mechanism

The bacterial type VI secretion system (T6SS) secretes many toxic effectors to gain advantage in interbacterial competition and for eukaryotic host infection. The cognate immunity proteins of these effectors protect bacteria from their own effectors. PldB is a T6SS trans-kingdom effector in Pseudomonas aeruginosa that can infect both prokaryotic and eukaryotic cells. Three proteins, PA5086, PA5087 and PA5088, are employed to suppress the toxicity of PldB-family proteins. The structures of PA5087 and PA5088 have previously been reported, but the identification of further distinctions between these immunity proteins is needed. Here, the crystal structure of PA5086 is reported at 1.90 Å resolution. A structural comparison of the three PldB immunity proteins showed vast divergences in their electrostatic potential surfaces. This interesting phenomenon provides an explanation of the stockpiling mechanism of T6SS immunity proteins.




proteins

Bond-valence analyses of the crystal structures of FeMo/V cofactors in FeMo/V proteins

The bond-valence method was performed on 51 crystal data sets from nitrogenase proteins, indicating the presence of molybdenum(III) in FeMo cofactors and vanadium(III) with more reduced iron complements in FeV cofactors.




proteins

Structures of three ependymin-related proteins suggest their function as a hydrophobic molecule binder

Ependymin was first discovered as a predominant protein in brain extracellular fluid in fish and was suggested to be involved in functions mostly related to learning and memory. Orthologous proteins to ependymin called ependymin-related proteins (EPDRs) have been found to exist in various tissues from sea urchins to humans, yet their functional role remains to be revealed. In this study, the structures of EPDR1 from frog, mouse and human were determined and analyzed. All of the EPDR1s fold into a dimer using a monomeric subunit that is mostly made up of two stacking antiparallel β-sheets with a curvature on one side, resulting in the formation of a deep hydrophobic pocket. All six of the cysteine residues in the monomeric subunit participate in the formation of three intramolecular disulfide bonds. Other interesting features of EPDR1 include two asparagine residues with glycosylation and a Ca2+-binding site. The EPDR1 fold is very similar to the folds of bacterial VioE and LolA/LolB, which also use a similar hydrophobic pocket for their respective functions as a hydrophobic substrate-binding enzyme and a lipoprotein carrier, respectively. A further fatty-acid binding assay using EPDR1 suggests that it indeed binds to fatty acids, presumably via this pocket. Additional interactome analysis of EPDR1 showed that EPDR1 interacts with insulin-like growth factor 2 receptor and flotillin proteins, which are known to be involved in protein and vesicle translocation.




proteins

fragHAR: towards ab initio quantum-crystallographic X-ray structure refinement for polypeptides and proteins

The first ab initio aspherical structure refinement against experimental X-ray structure factors for polypeptides and proteins using a fragmentation approach to break up the protein into residues and solvent, thereby speeding up quantum-crystallographic Hirshfeld atom refinement (HAR) calculations, is described. It it found that the geometric and atomic displacement parameters from the new fragHAR method are essentially unchanged from a HAR on the complete unfragmented system when tested on dipeptides, tripeptides and hexapeptides. The largest changes are for the parameters describing H atoms involved in hydrogen-bond interactions, but it is shown that these discrepancies can be removed by including the interacting fragments as a single larger fragment in the fragmentation scheme. Significant speed-ups are observed for the larger systems. Using this approach, it is possible to perform a highly parallelized HAR in reasonable times for large systems. The method has been implemented in the TONTO software.




proteins

Non-merohedral twinning: from minerals to proteins

In contrast to twinning by merohedry, the reciprocal lattices of the different domains of non-merohedral twins do not overlap exactly. This leads to three kinds of reflections: reflections with no overlap, reflections with an exact overlap and reflections with a partial overlap of a reflection from a second domain. This complicates the unit-cell determination, indexing, data integration and scaling of X-ray diffraction data. However, with hindsight it is possible to detwin the data because there are reflections that are not affected by the twinning. In this article, the successful solution and refinement of one mineral, one organometallic and two protein non-merohedral twins using a common strategy are described. The unit-cell constants and the orientation matrices were determined by the program CELL_NOW. The data were then integrated with SAINT. TWINABS was used for scaling, empirical absorption corrections and the generation of two different data files, one with detwinned data for structure solution and refinement and a second one for (usually more accurate) structure refinement against total integrated intensities. The structures were solved by experimental phasing using SHELXT for the first two structures and SHELXC/D/E for the two protein structures; all models were refined with SHELXL.




proteins

Crystal structures of the Bacillus subtilis prophage lytic cassette proteins XepA and YomS

As part of the Virus-X Consortium that aims to identify and characterize novel proteins and enzymes from bacteriophages and archaeal viruses, the genes of the putative lytic proteins XepA from Bacillus subtilis prophage PBSX and YomS from prophage SPβ were cloned and the proteins were subsequently produced and functionally characterized. In order to elucidate the role and the molecular mechanism of XepA and YomS, the crystal structures of these proteins were solved at resolutions of 1.9 and 1.3 Å, respectively. XepA consists of two antiparallel β-sandwich domains connected by a 30-amino-acid linker region. A pentamer of this protein adopts a unique dumbbell-shaped architecture consisting of two discs and a central tunnel. YomS (12.9 kDa per monomer), which is less than half the size of XepA (30.3 kDa), shows homology to the C-terminal part of XepA and exhibits a similar pentameric disc arrangement. Each β-sandwich entity resembles the fold of typical cytoplasmic membrane-binding C2 domains. Only XepA exhibits distinct cytotoxic activity in vivo, suggesting that the N-terminal pentameric domain is essential for this biological activity. The biological and structural data presented here suggest that XepA disrupts the proton motive force of the cytoplasmatic membrane, thus supporting cell lysis.




proteins

Characterization of the Pseudomonas aeruginosa T6SS PldB immunity proteins PA5086, PA5087 and PA5088 explains a novel stockpiling mechanism

The structure of the Pseudomonas aeruginosa T6SS PldB immunity protein PA5086 is reported at 1.9 Å resolution. Comparison of PA5086 with its homologs PA5087 and PA5088 showed great similarities in sequence and structure, but vast divergences in electrostatic potential surfaces.




proteins

Bond-valence analyses of the crystal structures of FeMo/V cofactors in FeMo/V proteins

The bond-valence method has been used for valence calculations of FeMo/V cofactors in FeMo/V proteins using 51 crystallographic data sets of FeMo/V proteins from the Protein Data Bank. The calculations show molybdenum(III) to be present in MoFe7S9C(Cys)(HHis)[R-(H)homocit] (where H4homocit is homocitric acid, HCys is cysteine and HHis is histidine) in FeMo cofactors, while vanadium(III) with a more reduced iron complement is obtained for FeV cofactors. Using an error analysis of the calculated valences, it was found that in FeMo cofactors Fe1, Fe6 and Fe7 can be unambiguously assigned as iron(III), while Fe2, Fe3, Fe4 and Fe5 show different degrees of mixed valences for the individual Fe atoms. For the FeV cofactors in PDB entry 5n6y, Fe4, Fe5 and Fe6 correspond to iron(II), iron(II) and iron(III), respectively, while Fe1, Fe2, Fe3 and Fe7 exhibit strongly mixed valences. Special situations such as CO-bound and selenium-substituted FeMo cofactors and O(N)H-bridged FeV cofactors are also discussed and suggest rearrangement of the electron configuration on the substitution of the bridging S atoms.




proteins

EML4-ALK V3 oncogenic fusion proteins promote microtubule stabilization and accelerated migration through NEK9 and NEK7 [RESEARCH ARTICLE]

Laura O'Regan, Giancarlo Barone, Rozita Adib, Chang Gok Woo, Hui Jeong Jeong, Emily L. Richardson, Mark W. Richards, Patricia A.J. Muller, Spencer J. Collis, Dean A. Fennell, Jene Choi, Richard Bayliss, and Andrew M. Fry

EML4-ALK is an oncogenic fusion present in ~5% non-small cell lung cancers. However, alternative breakpoints in the EML4 gene lead to distinct variants with different patient outcomes. Here, we show in cell models that EML4-ALK variant 3 (V3), which is linked to accelerated metastatic spread, causes microtubule stabilization, formation of extended cytoplasmic protrusions and increased cell migration. It also recruits the NEK9 and NEK7 kinase to microtubules via the N-terminal EML4 microtubule-binding region. Overexpression of wild-type EML4 as well as constitutive activation of NEK9 also perturb cell morphology and accelerate migration in a microtubule-dependent manner that requires the downstream kinase NEK7 but not ALK activity. Strikingly, elevated NEK9 expression is associated with reduced progression-free survival in EML4-ALK patients. Hence, we propose that EML4-ALK V3 promotes microtubule stabilization through NEK9 and NEK7 leading to increased cell migration. This represents a novel actionable pathway that could drive metastatic disease progression in EML4-ALK lung cancer.




proteins

Students dive into 3-D proteins

Video: Virtual reality immerses students in proteins and peptides.



  • Research & Innovations

proteins

Study weighs environmental costs of proteins

Beef and farmed catfish aren't great on the environment, but wild-caught fish and farmed shellfish have low environmental impacts.



  • Wilderness & Resources

proteins

Computer-designed proteins could counteract chemical weapons

Custom-designed proteins made with the aid of computers could fight chemical weapons such as nerve gas and help decontaminate toxic-waste sites, scientists say.



  • Research & Innovations

proteins

New Alzheimer’s Nasal Spray Shown to Reduce Proteins Which Cause the Disease in Mice

Kyoto University researchers said the vaccine for Alzheimer’s was effective and was also shown to have zero side effects observed in the mice.

The post New Alzheimer’s Nasal Spray Shown to Reduce Proteins Which Cause the Disease in Mice appeared first on Good News Network.




proteins

Method of labeling sulfenic acid-containing proteins and peptides

A method of labeling a sulfenic acid (—SOH) group of a cysteine residue in a protein; or peptide, comprises contacting said protein or peptide with a beta-ketoester to covalently couple said beta-ketoester to said cysteine residue and form a beta-ketoester-labeled cysteine residue in said protein or peptide.




proteins

Near infrared fluorogen and fluorescent activating proteins for in vivo imaging and live-cell biosensing

Tissue slices and whole organisms offer substantial challenges to fluorescence imaging. Autofluorescence and absorption via intrinsic chromophores, such as flavins, melanin, and hemoglobins, confound and degrade output from all fluorescent tags. An “optical window,” farther red than most autofluorescence sources and in a region of low hemoglobin and water absorbance, lies between 650 and 900 nm. This valley of relative optical clarity is an attractive target for fluorescence-based studies within tissues, intact organs, and living organisms. Novel fluorescent tags were developed herein, based upon a genetically targeted fluorogen activating protein and cognate fluorogenic dye that yields emission with a peak at 733 nm exclusively when complexed as a “fluoromodule”. This tool improves substantially over previously described far-red/NIR fluorescent proteins in terms of brightness, wavelength, and flexibility by leveraging the flexibility of synthetic chemistry to produce novel chromophores.




proteins

Four branched dendrimer-PEG for conjugation to proteins and peptides

A polymeric dendrimer-like structure with four branches of monomethoxy-polyethylene glycol that can be represented as: The carboxylic group of the previous structure can be functionalized for the production of conjugates of pharmaceutical interest. The binding of this dendrimer-like polyethylene glycol to therapeutic proteins improves their in vitro and in vivo stability.




proteins

Compounds that inhibit Hsp90 protein-protein interactions with IAP proteins

Disclosed herein are compounds that inhibit Hsp90 interactions with IAP proteins, such as Survivin, XIAP, cIAP1, or cIAP2, and methods for identifying and using such compounds.




proteins

Muteins of hNGAL and related proteins with affinity for a given target

The present invention relates to novel muteins derived from human lipocalin 2 (hNGAL) and related proteins that bind a given non-natural ligand with detectable affinity. The invention also related to corresponding nucleic acid molecules encoding such a mutein and to a method for their generation. The invention further relates to a method for producing such a mutein. Furthermore, the invention is directed to a pharmaceutical composition comprising such a lipocalin mutein as well as to various uses of the mutein.




proteins

Controlled cross-linking processing of proteins

A method of forming a cross-linked protein structures includes preparing a solution of protein dissolved in a benign solvent and forming an intermediate protein structure from the solution. The intermediate protein structure can be cross-linked by providing for a specific ratio of chemical cross-linking agents to form the cross-linked protein structure. The solution can be prepared by adding a cross-linker of N-hydroxysuccinimide (NHS) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) at a ratio of two-to-one of NHS to EDC to alcohol. PBS buffer (20×) can be added to the solution until the volume ratio of PBS buffer (20×) to alcohol is about one-to-one. About 16 percent by weight of protein can be dissolved in the solution. The solution can be electrospun to form an intermediate protein structure. After a period of time, the protein structure can be cross-linked to form the cross-linked protein structure.




proteins

Single-domain antigen-binding proteins that bind mammalian IgG

The present application relates to antigen-binding proteins that are capable of binding to mammalian IgG. The frame-work regions of the antigen-binding proteins of the application preferably correspond to those of antibodies naturally that are devoid of light chains as may e.g. be found in camelids. The application further relates to nucleic acids that encode such antigen-binding proteins, to immunoadsorbent materials that comprise such proteins, to the uses of such immunoadsorbent materials for the purification of mammalian IgG antibodies and for therapeutic apheresis.




proteins

HLA-restricted, peptide-specific antigen binding proteins

Antigen binding proteins with T cell receptor-like paratopes, that is, with an antigen binding region specific for an human leukocyte antigen-A2 restricted peptide are disclosed. The antigen binding proteins encompass antibodies in a variety of forms, including full-length antibodies, substantially intact antibodies, Fab fragments, F(ab')2 fragments, and single chain Fv fragments. Fusion proteins, such as scFv fusions with immunoglobulin or T-cell receptor domains, incorporating the specificity of the antigen binding region for each peptide are also contemplated by the invention. Furthermore, immunoconjugates may include antibodies to which is linked a radioisotope, fluorescent or other detectable marker, cytotoxin, or other molecule are also encompassed by the invention. Among other things, immunoconjugates can be used for delivery of an agent to elicit a therapeutic effect or to facilitate an immune effector function.




proteins

DNA-binding proteins and uses thereof

Disclosed herein are polypeptides, polynucleotides encoding, cells and organisms comprising novel DNA-binding domains, including TALE DNA-binding domains. Also disclosed are methods of using these novel DNA-binding domains for modulation of gene expression and/or genomic editing of endogenous cellular sequences.




proteins

IL4/IL13 binding repeat proteins and uses

IL4/IL13-binding proteins comprise binding domains, which inhibit IL4/IL13 binding to IL4Ralpaha and common gamma chain complexes (Type 1) and inhibit IL4 binding to IL4Ralpha and IL13Ralpha1 complexes (Type 2), and IL13 binding to IL13Ralpha1 and/or IL13Ralpha2, are useful in the treatment of cancer, inflammatory, and other pathological conditions, such as allergic or fibrotic conditions, especially pulmonary conditions.




proteins

Immunological Targeting of Pathological Tau Proteins

The present invention relates to methods and compositions for treating, preventing, and diagnosing Alzheimer's Disease or other tauopathies in a subject by administering an immunogenic tau peptide or an antibody recognizing the immunogenic tau epitope under conditions effective to treat, prevent, or diagnose Alzheimer's Disease or other tauopathies. Also disclosed are methods of promoting clearance of aggregates from the brain of the subject and of slowing progression of tau-pathology related behavioral phenotype in a subject.




proteins

Human Antigen Binding Proteins That Bind To a Complex Comprising beta-Klotho and an FGF Receptor

The present invention provides compositions and methods relating to or derived from antigen binding proteins capable of inducing B-Klotho, and or FGF21-like mediated signaling. In embodiments, the antigen binding proteins specifically bind to a complex comprising β-Klotho and at least one of (i) FGFR1c, (ii) FGFR2c and (iii) FGFR3c. In some embodiments the antigen binding proteins induce FGF21-like signaling. In some embodiments, an antigen binding protein is a fully human, humanized, or chimeric antibodies, binding fragments and derivatives of such antibodies, and polypeptides that specifically bind to a complex comprising β-Klotho and at least one of (i) FGFR1c, (ii) FGFR2c and (iii) FGFR3c. Other embodiments provide nucleic acids encoding such antigen binding proteins, and fragments and derivatives thereof, and polypeptides, cells comprising such polynucleotides, methods of making such antigen binding proteins, and fragments and derivatives thereof, and polypeptides, and methods of using such antigen binding proteins, fragments and derivatives thereof, and polypeptides, including methods of treating or diagnosing subjects suffering from type 2 diabetes, obesity, NASH, metabolic syndrome and related disorders or conditions.




proteins

Wheat allergy, intolerance breakthrough could see harmful proteins bred out of varieties

Researchers have identified all the immune reactive proteins, then mapped and identified the parts causing chronic wheat ailments, giving growers a path to develop new lines.




proteins

Heterotrimeric Gq proteins as therapeutic targets? [Molecular Bases of Disease]

Heterotrimeric G proteins are the core upstream elements that transduce and amplify the cellular signals from G protein–coupled receptors (GPCRs) to intracellular effectors. GPCRs are the largest family of membrane proteins encoded in the human genome and are the targets of about one-third of prescription medicines. However, to date, no single therapeutic agent exerts its effects via perturbing heterotrimeric G protein function, despite a plethora of evidence linking G protein malfunction to human disease. Several recent studies have brought to light that the Gq family–specific inhibitor FR900359 (FR) is unexpectedly efficacious in silencing the signaling of Gq oncoproteins, mutant Gq variants that mostly exist in the active state. These data not only raise the hope that researchers working in drug discovery may be able to potentially strike Gq oncoproteins from the list of undruggable targets, but also raise questions as to how FR achieves its therapeutic effect. Here, we place emphasis on these recent studies and explain why they expand our pharmacological armamentarium for targeting Gq protein oncogenes as well as broaden our mechanistic understanding of Gq protein oncogene function. We also highlight how this novel insight impacts the significance and utility of using G(q) proteins as targets in drug discovery efforts.




proteins

Distinct and Overlapping Sets of SUMO-1 and SUMO-2 Target Proteins Revealed by Quantitative Proteomics

Alfred C. O. Vertegaal
Dec 1, 2006; 5:2298-2310
Research




proteins

Fluorescent Proteins as Proteomic Probes

Ileana M. Cristea
Dec 1, 2005; 4:1933-1941
Research




proteins

Quantitative, Multiplexed Assays for Low Abundance Proteins in Plasma by Targeted Mass Spectrometry and Stable Isotope Dilution

Hasmik Keshishian
Dec 1, 2007; 6:2212-2229
Research




proteins

Comparative Proteomic Analysis of Eleven Common Cell Lines Reveals Ubiquitous but Varying Expression of Most Proteins

Tamar Geiger
Mar 1, 2012; 11:M111.014050-M111.014050
Special Issue: Prospects in Space and Time




proteins

Comparison of Label-free Methods for Quantifying Human Proteins by Shotgun Proteomics

William M. Old
Oct 1, 2005; 4:1487-1502
Research




proteins

Quantitative Mass Spectrometric Multiple Reaction Monitoring Assays for Major Plasma Proteins

Leigh Anderson
Apr 1, 2006; 5:573-588
Research




proteins

Absolute Quantification of Proteins by LCMSE: A Virtue of Parallel ms Acquisition

Jeffrey C. Silva
Jan 1, 2006; 5:144-156
Research




proteins

A Versatile Nanotrap for Biochemical and Functional Studies with Fluorescent Fusion Proteins

Ulrich Rothbauer
Feb 1, 2008; 7:282-289
Research




proteins

Phosphate-binding Tag, a New Tool to Visualize Phosphorylated Proteins

Eiji Kinoshita
Apr 1, 2006; 5:749-757
Technology




proteins

Heterotrimeric Gq proteins as therapeutic targets? [Molecular Bases of Disease]

Heterotrimeric G proteins are the core upstream elements that transduce and amplify the cellular signals from G protein–coupled receptors (GPCRs) to intracellular effectors. GPCRs are the largest family of membrane proteins encoded in the human genome and are the targets of about one-third of prescription medicines. However, to date, no single therapeutic agent exerts its effects via perturbing heterotrimeric G protein function, despite a plethora of evidence linking G protein malfunction to human disease. Several recent studies have brought to light that the Gq family–specific inhibitor FR900359 (FR) is unexpectedly efficacious in silencing the signaling of Gq oncoproteins, mutant Gq variants that mostly exist in the active state. These data not only raise the hope that researchers working in drug discovery may be able to potentially strike Gq oncoproteins from the list of undruggable targets, but also raise questions as to how FR achieves its therapeutic effect. Here, we place emphasis on these recent studies and explain why they expand our pharmacological armamentarium for targeting Gq protein oncogenes as well as broaden our mechanistic understanding of Gq protein oncogene function. We also highlight how this novel insight impacts the significance and utility of using G(q) proteins as targets in drug discovery efforts.




proteins

Detailed analyses of the crucial functions of Zn transporter proteins in alkaline phosphatase activation [Enzymology]

Numerous zinc ectoenzymes are metalated by zinc and activated in the compartments of the early secretory pathway before reaching their destination. Zn transporter (ZNT) proteins located in these compartments are essential for ectoenzyme activation. We have previously reported that ZNT proteins, specifically ZNT5–ZNT6 heterodimers and ZNT7 homodimers, play critical roles in the activation of zinc ectoenzymes, such as alkaline phosphatases (ALPs), by mobilizing cytosolic zinc into these compartments. However, this process remains incompletely understood. Here, using genetically-engineered chicken DT40 cells, we first determined that Zrt/Irt-like protein (ZIP) transporters that are localized to the compartments of the early secretory pathway play only a minor role in the ALP activation process. These transporters included ZIP7, ZIP9, and ZIP13, performing pivotal functions in maintaining cellular homeostasis by effluxing zinc out of the compartments. Next, using purified ALP proteins, we showed that zinc metalation on ALP produced in DT40 cells lacking ZNT5–ZNT6 heterodimers and ZNT7 homodimers is impaired. Finally, by genetically disrupting both ZNT5 and ZNT7 in human HAP1 cells, we directly demonstrated that the tissue-nonspecific ALP-activating functions of both ZNT complexes are conserved in human cells. Furthermore, using mutant HAP1 cells, we uncovered a previously-unrecognized and unique spatial regulation of ZNT5–ZNT6 heterodimer formation, wherein ZNT5 recruits ZNT6 to the Golgi apparatus to form the heterodimeric complex. These findings fill in major gaps in our understanding of the molecular mechanisms underlying zinc ectoenzyme activation in the compartments of the early secretory pathway.




proteins

Apolipoproteins of HDL can directly mediate binding to the scavenger receptor SR-BI, an HDL receptor that mediates selective lipid uptake

S Xu
Jul 1, 1997; 38:1289-1298
Articles




proteins

A spectrophotometric assay for lipid peroxides in serum lipoproteins using a commercially available reagent

M el-Saadani
Apr 1, 1989; 30:627-630
Articles




proteins

Rapid method for the isolation of lipoproteins from human serum by precipitation with polyanions

M. Burstein
Nov 1, 1970; 11:583-595
Articles




proteins

Regulation of hepatic secretion of apolipoprotein B-containing lipoproteins: information obtained from cultured liver cells

JL Dixon
Feb 1, 1993; 34:167-179
Reviews




proteins

Identification of multiple subclasses of plasma low density lipoproteins in normal humans

Ronald M. Krauss
Jan 1, 1982; 23:97-104
Articles




proteins

Thematic review series: Adipocyte Biology. The perilipin family of structural lipid droplet proteins: stabilization of lipid droplets and control of lipolysis

Dawn L. Brasaemle
Dec 1, 2007; 48:2547-2559
Thematic Reviews




proteins

The amphipathic helix in the exchangeable apolipoproteins: a review of secondary structure and function

JP Segrest
Feb 1, 1992; 33:141-166
Reviews




proteins

Roles of the DOCK-D family proteins in a mouse model of neuroinflammation [Neurobiology]

The DOCK-D (dedicator of cytokinesis D) family proteins are atypical guanine nucleotide exchange factors that regulate Rho GTPase activity. The family consists of Zizimin1 (DOCK9), Zizimin2 (DOCK11), and Zizimin3 (DOCK10). Functions of the DOCK-D family proteins are presently not well-explored, and the role of the DOCK-D family in neuroinflammation is unknown. In this study, we generated three mouse lines in which DOCK9 (DOCK9−/−), DOCK10 (DOCK10−/−), or DOCK11 (DOCK11−/−) had been deleted and examined the phenotypic effects of these gene deletions in MOG35–55 peptide-induced experimental autoimmune encephalomyelitis, an animal model of the neuroinflammatory disorder multiple sclerosis. We found that all the gene knockout lines were healthy and viable. The only phenotype observed under normal conditions was a slightly smaller proportion of B cells in splenocytes in DOCK10−/− mice than in the other mouse lines. We also found that the migration ability of macrophages is impaired in DOCK10−/− and DOCK11−/− mice and that the severity of experimental autoimmune encephalomyelitis was ameliorated only in DOCK10−/− mice. No apparent phenotype was observed for DOCK9−/− mice. Further investigations indicated that lipopolysaccharide stimulation up-regulates DOCK10 expression in microglia and that microglial migration is decreased in DOCK10−/− mice. Up-regulation of C–C motif chemokine ligand 2 (CCL2) expression induced by activation of Toll-like receptor 4 or 9 signaling was reduced in DOCK10−/− astrocytes compared with WT astrocytes. Taken together, our findings suggest that DOCK10 plays a role in innate immunity and neuroinflammation and might represent a potential therapeutic target for managing multiple sclerosis.




proteins

The Secretome Profiling of a Pediatric Airway Epithelium Infected with hRSV Identified Aberrant Apical/Basolateral Trafficking and Novel Immune Modulating (CXCL6, CXCL16, CSF3) and Antiviral (CEACAM1) Proteins [Research]

The respiratory epithelium comprises polarized cells at the interface between the environment and airway tissues. Polarized apical and basolateral protein secretions are a feature of airway epithelium homeostasis. Human respiratory syncytial virus (hRSV) is a major human pathogen that primarily targets the respiratory epithelium. However, the consequences of hRSV infection on epithelium secretome polarity and content remain poorly understood. To investigate the hRSV-associated apical and basolateral secretomes, a proteomics approach was combined with an ex vivo pediatric human airway epithelial (HAE) model of hRSV infection (data are available via ProteomeXchange and can be accessed at https://www.ebi.ac.uk/pride/ with identifier PXD013661). Following infection, a skewing of apical/basolateral abundance ratios was identified for several individual proteins. Novel modulators of neutrophil and lymphocyte activation (CXCL6, CSF3, SECTM1 or CXCL16), and antiviral proteins (BST2 or CEACAM1) were detected in infected, but not in uninfected cultures. Importantly, CXCL6, CXCL16, CSF3 were also detected in nasopharyngeal aspirates (NPA) from hRSV-infected infants but not healthy controls. Furthermore, the antiviral activity of CEACAM1 against RSV was confirmed in vitro using BEAS-2B cells. hRSV infection disrupted the polarity of the pediatric respiratory epithelial secretome and was associated with immune modulating proteins (CXCL6, CXCL16, CSF3) never linked with this virus before. In addition, the antiviral activity of CEACAM1 against hRSV had also never been previously characterized. This study, therefore, provides novel insights into RSV pathogenesis and endogenous antiviral responses in pediatric airway epithelium.




proteins

Templated folding of intrinsically disordered proteins [Molecular Biophysics]

Much of our current knowledge of biological chemistry is founded in the structure-function relationship, whereby sequence determines structure that determines function. Thus, the discovery that a large fraction of the proteome is intrinsically disordered, while being functional, has revolutionized our understanding of proteins and raised new and interesting questions. Many intrinsically disordered proteins (IDPs) have been determined to undergo a disorder-to-order transition when recognizing their physiological partners, suggesting that their mechanisms of folding are intrinsically different from those observed in globular proteins. However, IDPs also follow some of the classic paradigms established for globular proteins, pointing to important similarities in their behavior. In this review, we compare and contrast the folding mechanisms of globular proteins with the emerging features of binding-induced folding of intrinsically disordered proteins. Specifically, whereas disorder-to-order transitions of intrinsically disordered proteins appear to follow rules of globular protein folding, such as the cooperative nature of the reaction, their folding pathways are remarkably more malleable, due to the heterogeneous nature of their folding nuclei, as probed by analysis of linear free-energy relationship plots. These insights have led to a new model for the disorder-to-order transition in IDPs termed “templated folding,” whereby the binding partner dictates distinct structural transitions en route to product, while ensuring a cooperative folding.




proteins

Heterotrimeric Gq proteins as therapeutic targets? [Molecular Bases of Disease]

Heterotrimeric G proteins are the core upstream elements that transduce and amplify the cellular signals from G protein–coupled receptors (GPCRs) to intracellular effectors. GPCRs are the largest family of membrane proteins encoded in the human genome and are the targets of about one-third of prescription medicines. However, to date, no single therapeutic agent exerts its effects via perturbing heterotrimeric G protein function, despite a plethora of evidence linking G protein malfunction to human disease. Several recent studies have brought to light that the Gq family–specific inhibitor FR900359 (FR) is unexpectedly efficacious in silencing the signaling of Gq oncoproteins, mutant Gq variants that mostly exist in the active state. These data not only raise the hope that researchers working in drug discovery may be able to potentially strike Gq oncoproteins from the list of undruggable targets, but also raise questions as to how FR achieves its therapeutic effect. Here, we place emphasis on these recent studies and explain why they expand our pharmacological armamentarium for targeting Gq protein oncogenes as well as broaden our mechanistic understanding of Gq protein oncogene function. We also highlight how this novel insight impacts the significance and utility of using G(q) proteins as targets in drug discovery efforts.