2,227 research outputs found

    BLISTER-regulated vegetative growth is dependent on the protein kinase domain of ER stress modulator IRE1A in Arabidopsis thaliana

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    The unfolded protein response (UPR) is required for protein homeostasis in the endoplasmic reticulum (ER) when plants are challenged by adverse environmental conditions. Inositol-requiring enzyme 1 (IRE1), the bifunctional protein kinase / ribonuclease, is an important UPR regulator in plants mediating cytoplasmic splicing of the mRNA encoding the transcription factor bZIP60. This activates the UPR signaling pathway and regulates canonical UPR genes. However, how the protein activity of IRE1 is controlled during plant growth and development is largely unknown. In the present study, we demonstrate that the nuclear and Golgi-localized protein BLISTER (BLI) negatively controls the activity of IRE1A/IRE1B under normal growth condition in Arabidopsis. Loss-of-function mutation of BLI results in chronic up-regulation of a set of both canonical UPR genes and non-canonical UPR downstream genes, leading to cell death and growth retardation. Genetic analysis indicates that BLI-regulated vegetative growth phenotype is dependent on IRE1A/IRE1B but not their canonical splicing target bZIP60. Genetic complementation with mutation analysis suggests that the D570/K572 residues in the ATP-binding pocket and N780 residue in the RNase domain of IRE1A are required for the activation of canonical UPR gene expression, in contrast, the D570/K572 residues and D590 residue in the protein kinase domain of IRE1A are important for the induction of non-canonical UPR downstream genes in the BLI mutant background, which correlates with the shoot growth phenotype. Hence, our results reveal the important role of IRE1A in plant growth and development, and BLI negatively controls IRE1A’s function under normal growth condition in plants

    Statistical Modeling of RNA-Seq Data

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    Recently, ultra high-throughput sequencing of RNA (RNA-Seq) has been developed as an approach for analysis of gene expression. By obtaining tens or even hundreds of millions of reads of transcribed sequences, an RNA-Seq experiment can offer a comprehensive survey of the population of genes (transcripts) in any sample of interest. This paper introduces a statistical model for estimating isoform abundance from RNA-Seq data and is flexible enough to accommodate both single end and paired end RNA-Seq data and sampling bias along the length of the transcript. Based on the derivation of minimal sufficient statistics for the model, a computationally feasible implementation of the maximum likelihood estimator of the model is provided. Further, it is shown that using paired end RNA-Seq provides more accurate isoform abundance estimates than single end sequencing at fixed sequencing depth. Simulation studies are also given.Comment: Published in at http://dx.doi.org/10.1214/10-STS343 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

    Plasma cholesterol esterase level is a determinant for an atherogenic lipoprotein profile in normolipidemic human subjects

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    AbstractPlasma cholesterol level is controlled by various factors. In the present study, high plasma activity of cholesterol esterase was found to correlate with plasma total cholesterol and low density lipoprotein (LDL) cholesterol levels in normolipidemic human subjects. However, the cholesterol esterase is not elevated in plasma of patients with familial hypercholesterolemia. These observations suggest that cholesterol esterase level is not determined by plasma cholesterol level, but elevated cholesterol esterase may be causative in increasing plasma cholesterol and LDL. Additional experiments further demonstrated that cholesterol esterase can convert the larger and less-atherogenic LDL to the smaller and more atherogenic LDL subspecies in vitro. These results suggest that plasma cholesterol esterase contributes to the formation and accumulation of atherogenic lipoproteins, and thus is a major risk factor for premature atherosclerosis in normal human subjects

    Dissociation channel dependence on peptide size observed in electron capture dissociation of tryptic peptides

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    International audienceElectron capture dissociation (ECD) of a series of five residue peptides led to the observation that these small peptides did not lead to the formation of the usual c/z ECD fragments, but to a, b, y and w fragments. In order to determine how general this behavior is for small sized peptides, the effect of peptide size on ECD fragments using a complete set of ECD spectra from the SwedECD spectra database was examined. Analysis of the database shows that b and w fragments are favored for small peptide sizes and that average fragment size shows a linear relationship to parent peptide size for most fragment types. From these data, it appears that most of the w fragments are not secondary fragments of the major z ions, in sharp contrast with the proposed mechanism leading to these ions. These data also show that c fragment distributions depend strongly on the nature of C-terminal residue basic site: arginine leads to loss of short neutral fragments, whereas lysine leads to loss of longer neutral fragments. It also appears that b ions might be produced by two different mechanisms depending on the parent peptide size. A model for the fragmentation pathways in competition is proposed. These relationships between average fragment size and parent peptide size could be further exploited also for CID fragment spectra and could be included in fragmentation prediction algorithms

    Protecting Expert Advice for the Public: Promoting Safety and Improved Communications

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    The drivers of the harassment and intimidation of researchers are complex, widespread, and global in their reach and were being studied across many disciplines even before COVID-19. This policy briefing reviews some of the scholarship on this wide-ranging problem but focuses on what can be done to help ensure that Canadians fully benefit from the work of Canada’s researchers while also preserving the security and safety of those researchers. It identifies policies and actions that can be implemented in the near term to gather information on the problem, better frame public research communications, and ensure that mechanisms are readily available to support researchers who are threatened. The policy briefing is concerned with researchers, but these behaviours are also harming journalists, politicians, public health communicators, and many others more fully in the public eye than researchers. Some recommendations here may help to address this wider problem

    Phase separation of signaling molecules promotes T cell receptor signal transduction

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    Author Posting. © The Author(s), 2016. This is the author's version of the work. It is posted here by permission of American Association for the Advancement of Science for personal use, not for redistribution. The definitive version was published in Science 352 (2016): 595-599, doi:10.1126/science.aad9964.Activation of various cell surface receptors triggers the reorganization of downstream signaling molecules into micron- or submicron-sized clusters. However, the functional consequences of such clustering has been unclear. We biochemically reconstituted a 12-component signaling pathway on model membranes, beginning with T cell receptor (TCR) activation and ending with actin assembly. When TCR phoshophorylation was triggered, downstream signaling proteins spontaneously separated into liquid-like clusters that promoted signaling outputs both in vitro and in human Jurkat T cells. Reconstituted clusters were enriched in kinases but excluded phosphatases, and enhanced actin filament assembly by recruiting and organizing actin regulators. These results demonstrate that protein phase separation can create a distinct physical and biochemical compartment that facilitates signaling.This work was supported by the HCIA program of HHMI, the NIH (R01-GM56322 to M.K.R.) and Welch Foundation (I–1544 to M.K.R.). X.S. was supported by CRI Irvington postdoctoral fellowship. J.A.D. was supported by NRSA F32 award 5-F32-DK101188. E.H. was supported as a fellow of the Leukemia and Lymphoma Society. J.O. was supported by funds from Tobacco-Related Disease Research Program of the University of California (19FT-0090).2016-10-0

    The global landscape of approved antibody therapies

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    Antibody therapies have become an important class of therapeutics in recent years as they have exhibited outstanding efficacy and safety in the treatment of several major diseases including cancers, immune-related diseases, infectious disease and hematological disease. There has been significant progress in the global research and development landscape of antibody therapies in the past decade. In this review, we have collected available data from the Umabs Antibody Therapies Database (Umabs-DB, https://umabs.com) as of 30 June 2022. The Umabs-DB shows that 162 antibody therapies have been approved by at least one regulatory agency in the world, including 122 approvals in the US, followed by 114 in Europe, 82 in Japan and 73 in China, whereas biosimilar, diagnostic and veterinary antibodies are not included in our statistics. Although the US and Europe have been at the leading position for decades, rapid advancement has been witnessed in Japan and China in the past decade. The approved antibody therapies include 115 canonical antibodies, 14 antibody-drug conjugates, 7 bispecific antibodies, 8 antibody fragments, 3 radiolabeled antibodies, 1 antibody-conjugate immunotoxin, 2 immunoconjugates and 12 Fc-Fusion proteins. They have been developed against 91 drug targets, of which PD-1 is the most popular, with 14 approved antibody-based blockades for cancer treatment in the world. This review outlined the global landscape of the approved antibody therapies with respect to the regulation agencies, therapeutic targets and indications, aiming to provide an insight into the trends of the global development of antibody therapies
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