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.

Aspergillus flavus (A. flavus), a pathogenic fungus, can produce carcinogenic and toxic aflatoxins that are a serious agricultural and medical threat worldwide. Attempts to decipher the aflatoxin biosynthetic pathway have been hampered by the lack of a high-quality genome annotation for A. flavus. To address this gap, we performed a comprehensive proteogenomic analysis using high-accuracy mass spectrometry data for this pathogen. The resulting high-quality dataset confirmed the translation of 8,724 previously-predicted genes, and identified 732 novel proteins, 269 splice variants, 447 single amino acid variants, 188 revised genes. A subset of novel proteins was experimentally validated by RT-PCR and synthetic peptides. Further functional annotation suggested that a number of the identified novel proteins may play roles in aflatoxin biosynthesis and stress responses in A. flavus. This comprehensive strategy also identified a wide range of post-translational modifications (PTMs), including 3,461 modification sites from 1,765 proteins. Functional analysis suggested the involvement of these modified proteins in the regulation of cellular metabolic and aflatoxin biosynthetic pathways. Together, we provided a high quality annotation of A. flavus genome and revealed novel insights into the mechanisms of aflatoxin production and pathogenicity in this pathogen.

Extracellular vesicle (EV) proteins from acute myeloid leukemia (AML) cell lines were analyzed using mass spectrometry. The analyses identified 2450 proteins, including 461 differentially expressed proteins (290 upregulated and 171 downregulated). CD53 and CD47 were upregulated and were selected as candidate biomarkers. The association between survival of patients with AML and the expression levels of CD53 and CD47 at diagnosis was analyzed using mRNA expression data from The Cancer Genome Atlas database. Patients with higher expression levels showed significantly inferior survival than those with lower expression levels. Enzyme-linked immunosorbent assay results of the expression levels of CD53 and CD47 from EVs in the bone marrow of patients with AML at diagnosis and at the time of complete remission with induction chemotherapy revealed that patients with downregulated CD53 and CD47 expression appeared to relapse less frequently. Network model analysis of EV proteins revealed several upregulated kinases, including LYN, CSNK2A1, SYK, CSK, and PTK2B. The potential cytotoxicity of several clinically applicable drugs that inhibit these kinases was tested in AML cell lines. The drugs lowered the viability of AML cells. The collective data suggest that AML-derived EVs could reflect essential leukemia biology.

Staphylococcus aureus is a major cause of infections worldwide and infection results in a variety of diseases. As of no surprise, protein phosphorylation is an important game player in signaling cascades and has been shown to be involved in S. aureus virulence. Albeit long neglected, eukaryotic-type serine/threonine kinases in S. aureus have been implicated in this complex signaling cascades. Due to the sub-stoichiometric nature of protein phosphorylation and a lack of suitable analysis tools, the knowledge of these cascades is however, to date, still limited.

Here, were apply an optimized protocol for efficient phosphopeptide enrichment via Fe3+-IMAC followed by LC-MS/MS to get a better understanding of the impact of protein phosphorylation on the complex signaling networks involved in pathogenicity. By profiling a serine/threonine kinase and phosphatase mutant from a methicillin-resistant S. aureus mutant library, we generated the most comprehensive phosphoproteome dataset of S. aureus to date, aiding a better understanding of signaling in bacteria. With the identification of 3800 class I p-sites we were able to increase the number of identifications by more than 21 times compared to recent literature. In addition, we were able to identify 74 downstream targets of the only reported eukaryotic-type Ser/Thr kinase of the S. aureus strain USA300, Stk1. This work allowed an extensive analysis of the bacterial phosphoproteome and indicates that Ser/Thr kinase signaling is far more abundant than previously anticipated in S. aureus.

The F-box protein MORE AXILLARY GROWTH 2 (MAX2) is a central component in the signaling cascade of strigolactones (SLs) as well as of the smoke derived karrikins (KARs) and the so far unknown endogenous KAI2 ligand (KL). The two groups of molecules are involved in overlapping and unique developmental processes, and signal-specific outcomes are attributed to perception by the paralogous α/β-hydrolases DWARF14 (D14) for SL and KARRIKIN INSENSITIVE 2/ HYPOSENSITIVE TO LIGHT (KAI2/HTL) for KAR/KL. Additionally, depending on which receptor is activated, specific members of the SUPPRESSOR OF MAX2 1 (SMAX1) – LIKE (SMXL) family control KAR/KL and SL responses. As proteins that function in the same signal transduction pathway often occur in large protein complexes, we aimed at discovering new players of the MAX2, D14 and KAI2 protein network by tandem affinity purification using Arabidopsis cell cultures. When using MAX2 as a bait, various proteins were co-purified among which general components of the Skp1-Cullin-F-box complex and members of the CONSTITUTIVE PHOTOMORPHOGENIC 9 signalosome. Here, we report the identification of a novel interactor of MAX2, a type 5 serine/threonine protein phosphatase, designated PHYTOCHROME-ASSOCIATED PROTEIN PHOSPHATASE 5 (PAPP5). Quantitative affinity purification pointed at PAPP5 as being more present in KAI2 rather than D14 protein complexes. In agreement, mutant analysis suggests that PAPP5 modulates KAR/KL-dependent seed germination in suboptimal conditions and seedling development. Additionally, a phosphopeptide enrichment experiment revealed that PAPP5 might dephosphorylate MAX2 in vivo independently of the synthetic strigolactone analog, rac-GR24. Together, by analyzing the protein complexes to which MAX2, D14 and KAI2 belong, we revealed a new MAX2 interactor, PAPP5, that might act through dephosphorylation of MAX2 to control mainly KAR/KL- related phenotypes and, hence, provide another link with the light pathway.

High performance liquid chromatography has been employed for decades to enhance detection sensitivity and quantification of complex analytes within biological mixtures. Among these analytes, glycans released from glycoproteins and glycolipids have been characterized as underivatized or fluorescently tagged derivatives by HPLC coupled to various detection methods. These approaches have proven extremely useful for profiling the structural diversity of glycoprotein and glycolipid glycosylation but require the availability of glycan standards and secondary orthogonal degradation strategies to validate structural assignments. A robust method for HPLC separation of glycans as their permethylated derivatives, coupled with in-line MSn fragmentation to assign structural features independent of standards, would significantly enhance the depth of knowledge obtainable from biological samples. Here, we report an optimized workflow for LC-MS analysis of permethylated glycans that includes sample preparation, mobile phase optimization, and MSn method development to resolve structural isomers on-the-fly. We report baseline separation and MSn fragmentation of isomeric N- and O-glycan structures, aided by supplementing mobile phases with Li+, which simplifies adduct heterogeneity and facilitates cross-ring fragmentation to obtain valuable monosaccharide linkage information. Our workflow has been adapted from standard proteomics-based workflows and, therefore, provides opportunities for laboratories with expertise in proteomics to acquire glycomic data with minimal deviation from existing buffer systems, chromatography media, and instrument configurations. Furthermore, our workflow does not require a mass spectrometer with high-resolution/accurate mass capabilities. The rapidly evolving appreciation of the biological significance of glycans for human health and disease requires the implementation of high-throughput methods to identify and quantify glycans harvested from sample sets of sufficient size to achieve appropriately powered statistical significance. The LC-MSn approach we report generates glycan isomeric separations, robust structural characterization, and is amenable to auto-sampling with associated throughput enhancements.

The faithful segregation, or “partition,” of many low-copy number bacterial plasmids is driven by plasmid-encoded ATPases that are represented by the P1 plasmid ParA protein. ParA binds to the bacterial nucleoid via an ATP-dependent nonspecific DNA (nsDNA)-binding activity, which is essential for partition. ParA also has a site-specific DNA-binding activity to the par operator (parOP), which requires either ATP or ADP, and which is essential for it to act as a transcriptional repressor but is dispensable for partition. Here we examine how DNA binding by ParA contributes to the relative distribution of its plasmid partition and repressor activities, using a ParA with an alanine substitution at Arg351, a residue previously predicted to participate in site-specific DNA binding. In vivo, the parAR351A allele is compromised for partition, but its repressor activity is dramatically improved so that it behaves as a “super-repressor.” In vitro, ParAR351A binds and hydrolyzes ATP, and undergoes a specific conformational change required for nsDNA binding, but its nsDNA-binding activity is significantly damaged. This defect in turn significantly reduces the assembly and stability of partition complexes formed by the interaction of ParA with ParB, the centromere-binding protein, and DNA. In contrast, the R351A change shows only a mild defect in site-specific DNA binding. We conclude that the partition defect is due to altered nsDNA binding kinetics and affinity for the bacterial chromosome. Furthermore, the super-repressor phenotype is explained by an increased pool of non-nucleoid bound ParA that is competent to bind parOP and repress transcription.

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.

In conversation with Ehud Barak 27 March 2023 — 12:00PM TO 1:00PM Anonymous (not verified) 21 March 2023 Chatham House and Online

The former prime minister of Israel discusses his country’s political outlook and foreign policy priorities.

On the eve of its 75th independence anniversary, Israel is at a critical crossroads. Weeks of long, intense protests surrounding judicial reforms pursued by the current government have widened the debate over the role played by the, so far independent, judiciary, notably the Supreme Court.

Supporters on both sides of the argument are fighting over different visions of Israel – a true liberal-democracy, or a much-reduced version of a democratic system. Whichever side of the argument people fall, the debate symbolizes tension in Israel’s society and decline in trust of its political and constitutional institutions.

Abroad, the situation remains intricate. Israel-Iran relations remain on a knife edge while the Abraham Accords normalized relations with parts of the Gulf. Then there are the continual issues surrounding relations with the Palestinians and their right to self-determination and statehood.

Old international challenges are now rubbing up against the new. Israel is part of a changing power dynamic in the Middle East, the result of a much-reduced US footprint. Furthermore, it must now contend with the other global superpower in China and continue to work on its response to the war in Ukraine.

Amid its domestic struggle to maintain its democratic character, fast-moving regional and international developments are in need of addressing. Friends and allies are deeply concerned with the country’s constitutional crisis, potentially re-evaluating their relations with the Jewish state.

Former prime minister of Israel Ehud Barak lays out his views on the complexities of domestic and international challenges facing Israel today.

Questions covered include:

• What are the main root causes of the current constitutional crisis, and how could it be best resolved?
• Could the current situation lead to a breakdown of the political system, even widespread violence?
• How could the current circumstances in Israel and Palestine affect relations between the two and any prospect for peace negotiations?
• How will US-Israel relations stand up against China’s influence in the region?
• What is Israel’s interpretation of the war in Ukraine and how is the country affected?

As with all member events, questions from the audience drive the conversation.

Kevin Costner says he didn't know about his "Yellowstone" character John Dutton's death until after the episode aired on Sunday.

Sara Giusto is a talent manager, but not in the sense you might imagine. Her biggest client is imma, an influencer with pink hair ... who isn't human. Giusto discusses what the rise of "virtual humans" means for the real world — and invites imma onstage to explore an important question: In an increasingly digital world, what's really real?

What we eat is less about what we choose and more about what’s offered to us, says food and climate expert Sarah Lake. Unpacking how governments and companies have driven up meat consumption in the US through extensive marketing, she explains how we could employ these same forces to incentivize plant-based eating — for the sake of the planet, public health and global food security.

Billions of dollars are poured into global development every year, but results are lacking, says economist Karthik Muralidharan. Diving into an example with public education, he outlines how smarter resource allocation and evidence-based interventions, like learning software that dynamically responds to students and teaches at the level that's right for them, can accelerate global development worldwide — not by spending more, but by spending smarter.

School districts must make amends for their racist history, writes Daarel Burnette II. What should that look like?

The New York state legislature passed a bill that would make the use of state test scores in these evaluations optional, leaving the decision up to districts and making it subject to collective bargaining.

A former high school athletic standout and homecoming king, Pedro Garcia III “could connect with anybody,” no matter the language, said a teaching colleague in Cozad, Neb.

As the number of charter schools continues to grow, voters in California will be forced to examine their largess.

UConn women’s basketball freshman Sarah Strong earned the first Big East Freshman of the Week honors of her career on Monday after a pair of impressive performances in the Huskies’ Week 1 wins. Strong was the No. 1 recruit in the Class of 2024 and lived up to her elite billing with a game-high 17 points in her college debut against Boston University on Thursday. She also led the team with six ...

Christelle Anaclet
Dec 12, 2012; 32:17970-17976
BehavioralSystemsCognitive

Randy L. Buckner
Aug 24, 2005; 25:7709-7717
Neurobiology of Disease

α-Neurexins are essential and highly expressed presynaptic cell-adhesion molecules that are frequently linked to neuropsychiatric and neurodevelopmental disorders. Despite their importance, how the elaborate extracellular sequences of α-neurexins contribute to synapse function is poorly understood. We recently characterized the presynaptic gain-of-function phenotype caused by a missense mutation in an evolutionarily conserved extracellular sequence of neurexin-3α (A687T) that we identified in a patient diagnosed with profound intellectual disability and epilepsy. The striking A687T gain-of-function mutation on neurexin-3α prompted us to systematically test using mutants whether the presynaptic gain-of-function phenotype is a consequence of the addition of side-chain bulk (i.e., A687V) or polar/hydrophilic properties (i.e., A687S). We used multidisciplinary approaches in mixed-sex primary hippocampal cultures to assess the impact of the neurexin-3α^A687 residue on synapse morphology, function and ligand binding. Unexpectedly, neither A687V nor A687S recapitulated the neurexin-3α A687T phenotype. Instead, distinct from A687T, molecular replacement with A687S significantly enhanced postsynaptic properties exclusively at excitatory synapses and selectively increased binding to neuroligin-1 and neuroligin-3 without changing binding to neuroligin-2 or LRRTM2. Importantly, we provide the first experimental evidence supporting the notion that the position A687 of neurexin-3α and the N-terminal sequences of neuroligins may contribute to the stability of α-neurexin–neuroligin-1 trans-synaptic interactions and that these interactions may specifically regulate the postsynaptic strength of excitatory synapses.

It is well established that holding information in working memory (WM) elicits sustained stimulus-specific patterns of neural activity. Nevertheless, here we provide evidence for a distinct class of neural activity that tracks the number of individuated items in working memory, independent of the type of visual features stored. We present two EEG studies of young adults of both sexes that provide robust evidence for a signal tracking the number of individuated representations in working memory, regardless of the specific feature values stored. In Study 1, subjects maintained either colors or orientations across separate blocks in a single session. We found near-perfect generalization of the load signal between these two conditions, despite being able to simultaneously decode which feature had been voluntarily stored. In Study 2, participants attended to two features with very distinct cortical representations: color and motion coherence. We again found evidence for a neural load signal that robustly generalized across these distinct visual features, even though cortically disparate regions process color and motion coherence. Moreover, representational similarity analysis provided converging evidence for a content-independent load signal, while simultaneously showing that unique variance in EEG activity tracked the specific features that were stored. We posit that this load signal reflects a content-independent "pointer" operation that binds objects to the current context while parallel but distinct neural signals represent the features that are stored for each item in memory.

Bagdad/Rome - FAO is scaling-up critical food and agriculture assistance to highly vulnerable rural households in Iraq thanks to a generous $14.7 million grant from Saudi Arabia. The donation is [...]

Policy makers should support a broad array of approaches to overhauling global food systems, [...]

Cellist Yo-Yo Ma talks with the founder of the Girls Computing League about the promise of her generation

Watch a video on the restoration of Gorongosa Park. The video was originally featured on Foreign Exchange with Fareed Zakaria and produced by the Pulitzer Center on Crisis Reporting.

In 1905, New York City hosted a grand procession for the last living soldier of a war that ended 90 years earlier

An incredible trove of archaeological artifacts has been unearthed once again at Saqqara—including 100 coffins, and incredibly rare statues dating back 4,500 years.

The facts of Sojourner Truth’s life are inspiring: Born into slavery in the late 1790s, she became an influential abolitionist and Pentecostal preacher, transfixing audiences from the mid 1840s through the late 1870s with her candid and powerful voice, not to mention her singing. Tall and strong, Truth was physically formidable, too. No one was using the term “intersectionality” in the 19th century, but Truth embodied this idea, declaring that her Blackness and her womanhood were equally essential facets of her identity. But many people, both in Truth’s lifetime and in the approximately 140 years since her death, have found it useful to recast Truth as they wish to remember her instead of as she was. There’s no better example of this than “Ain’t I a woman?,” the hypothetical that Truth supposedly put to the audience when she addressed a women’s rights convention in 1851 in Akron, Ohio—the city where a public plaza will be dedicated in her honor this spring. There’s reason to doubt she said that, or at least that she said it in that way. In this episode, we speak with two historians who’ve dug into Truth’s complicated legacy and challenged much of what’s been written about this American icon. Cynthia Greenlee reported on recent efforts to honor Truth (https://www.smithsonianmag.com/history/remarkable-untold-story-sojourner-truth-180983691/) for the March 2024 issue of Smithsonian. Nell Irvin Painter wrote the groundbreaking 1996 biography Sojourner Truth: A Life, A Symbol, and she’s hard at work on a follow-up volume titled Sojourner Truth Was a New Yorker and She Didn’t Say That. Together, Greenlee and Painter help us understand us who Sojourner Truth really was, and why several generations of activists have claimed her as a symbol — at the expense of our understanding of her as a person. Read Cynthia Greenlee’s March 2024 Smithsonian story about Sojourner Truth here (https://www.smithsonianmag.com/history/remarkable-untold-story-sojourner-truth-180983691/) . You can learn more about Dr. Greenlee and her work at her site (https://www.cynthiagreenlee.com/) . You can learn more about Dr. Nell Irvin Painter’s work as an author, artist, and historian at her site (http://www.nellpainter.com/) . And read more here for the history of Mar-a-Lago (https://www.smithsonianmag.com/history/history-mar-a-lago-180965214/) mentioned in our dinner party fact. Find prior episodes of our show here (https://www.smithsonianmag.com/podcast/) . There’s More to That is a production of Smithsonian magazine and PRX Productions. From the magazine, our team is Chris Klimek, Debra Rosenberg and Brian Wolly. From PRX, our team is Jessica Miller, Adriana Rosas Rivera, Genevieve Sponsler, Rye Dorsey, and Edwin Ochoa. The Executive Producer of PRX Productions is Jocelyn Gonzales. Fact-checking by Stephanie Abramson. Episode artwork by Emily Lankiewicz. Music by APM Music.

Sarah Parcak | Smithsonian Magazine’s 2016 American Ingenuity Award Winner for History This tech-savvy researcher of our past uses satellites and other remote-sensing tools to discover and explore stunning new evidence of lost cultures—including, just this year, another possible Viking site in North America. In addition, she has located an astonishing number of ancient Egyptian remains—thousands of settlements, lost tombs and hidden pyramids. A Yale- and Cambridge-trained Egyptologist and archaeologist, Parcak is a professor of anthropology at the University of Alabama at Birmingham, where she serves as founding director of the Laboratory for Global Observation. Read more about Parcak’s work: http://smithmag.co/ZuwTGP | #IngenuityAwards And more about the American Ingenuity Awards: http://smithmag.co/77xPqy

A Smithsonian entomologist demonstrates how tarantulas feed by placing live crickets inches from their jaws.

The “beloved” rodent named Cinnamon was spotted this week with help from drones. She has been wandering and eating grass after escaping her zoo enclosure last Friday

Pathogens are more common in polar bears living in the Chukchi Sea now than they were three decades ago, a new study suggests—but it's not yet clear what that means for the mammals' health

A century on, the country’s most beloved Thursday spectacle reaches new heights

Dominic April fell in love with forging after his career in the military came to an end in 2015. Now operating a blacksmith studio near Quebec City, he hopes to help other veterans dealing with PTSD find creativity and purpose.

Paraglider Ben Lewis remembers spinning around wildly as he got pulled up higher and higher into the violent storm. That was when he realized, about 6,700 metres up in the sky and still rising, that he was not likely to see his family again.

This will be the first Remembrance Day celebrated at the new Royal Canadian Legion in Sault Ste. Marie. Branch 25 recently opened a new complex in the northern Ontario city, complete with a 108-unit apartment tower.

An 18-year-old man charged with attempted murder in a small northern Ontario community made a brief court appearance today by video, and remains in custody. Meanwhile, community members gathered outside the courthouse for a rally.