Endosomal Sorting Complex Required for Transport (ESCRT) proteins can be transiently recruited to the plasma membrane for membrane repair and formation of extracellular vesicles. Here, we discovered micrometer-sized worm-shaped ESCRT structures that stably persist for multiple hours at the plasma membrane of macrophages, dendritic cells, and fibroblasts. These structures surround clusters of integrins and known cargoes of extracellular vesicles.
View Article and Find Full Text PDFDespite the global health burden, treatment of spontaneous intracerebral haemorrhage (ICH) is largely supportive, and translation of specific medical therapies has not been successful. Zebrafish larvae offer a unique platform for drug screening to rapidly identify neuroprotective compounds following ICH. We applied the Spectrum Collection library compounds to zebrafish larvae acutely after ICH to screen for decreased brain cell death and identified 150 successful drugs.
View Article and Find Full Text PDFDNA damage responses are crucial for plant growth under genotoxic stress. Accumulating evidence indicates that DNA damage responses differ between plant cell types. Here, quantitative shotgun phosphoproteomics provided high-throughput analysis of the DNA damage response network in callus cells.
View Article and Find Full Text PDFLeaves of transferred from low to high light increase their capacity for photosynthesis, a process of dynamic acclimation. A mutant, , lacking a chloroplast glucose-6-phosphate/phosphate translocator, is deficient in its ability to acclimate to increased light. Here, we have used a label-free proteomics approach, to perform relative quantitation of 1993 proteins from Arabidopsis wild type and leaves exposed to increased light.
View Article and Find Full Text PDFType 2 brittle cornea syndrome (BCS2) is an inherited connective tissue disease with a devastating ocular phenotype caused by mutations in the transcription factor PR domain containing 5 (PRDM5) hypothesized to exert epigenetic effects through histone and DNA methylation. Here we investigate clinical samples, including skin fibroblasts and retinal tissue from BCS2 patients, to elucidate the epigenetic role of PRDM5 and mechanisms of its dysregulation in disease. First we report abnormal retinal vascular morphology in the eyes of two cousins with BCS2 (PRDM5 Δ exons 9-14) using immunohistochemistry, and mine data from skin fibroblast expression microarrays from patients with PRDM5 mutations p.
View Article and Find Full Text PDFCell-extracellular matrix (ECM) adhesion is a fundamental requirement for multicellular existence due to roles in positioning, proliferation and differentiation. Phosphorylation plays a major role in adhesion signalling; however, a full understanding of the phosphorylation events that occur at sites of adhesion is lacking. Here we report a proteomic and phosphoproteomic analysis of adhesion complexes isolated from cells spread on fibronectin.
View Article and Find Full Text PDFPseudoachondroplasia and multiple epiphyseal dysplasia are genetic skeletal diseases resulting from mutations in cartilage structural proteins. Electron microscopy and immunohistochemistry previously showed that the appearance of the cartilage extracellular matrix (ECM) in targeted mouse models of these diseases is disrupted; however, the precise changes in ECM organization and the pathological consequences remain unknown. Our aim was to determine the effects of matrilin-3 and COMP mutations on the composition and extractability of ECM components to inform how these detrimental changes might influence cartilage organization and degeneration.
View Article and Find Full Text PDFActivation of hepatic stellate cells (HSCs) and subsequent uncontrolled accumulation of altered extracellular matrix (ECM) underpin liver fibrosis, a wound healing response to chronic injury, which can lead to organ failure and death. We sought to catalogue the components of fibrotic liver ECM to obtain insights into disease etiology and aid identification of new biomarkers. Cell-derived ECM was isolated from the HSC line LX-2, an in vitro model of liver fibrosis, and compared to ECM from human foreskin fibroblasts (HFFs) as a control.
View Article and Find Full Text PDFWe report the release of mzIdentML, an exchange standard for peptide and protein identification data, designed by the Proteomics Standards Initiative. The format was developed by the Proteomics Standards Initiative in collaboration with instrument and software vendors, and the developers of the major open-source projects in proteomics. Software implementations have been developed to enable conversion from most popular proprietary and open-source formats, and mzIdentML will soon be supported by the major public repositories.
View Article and Find Full Text PDFCellular stress can globally inhibit translation initiation, and glucose removal from yeast causes one of the most dramatic effects in terms of rapidity and scale. Here we show that the same rapid inhibition occurs during yeast growth as glucose levels diminish. We characterize this novel regulation showing that it involves alterations within the 48S preinitiation complex.
View Article and Find Full Text PDFeIF4E-binding proteins (4E-BPs) regulate translation of mRNAs in eukaryotes. However the extent to which specific mRNA targets are regulated by 4E-BPs remains unknown. We performed translational profiling by microarray analysis of polysome and monosome associated mRNAs in wild-type and mutant cells to identify mRNAs in yeast regulated by the 4E-BPs Caf20p and Eap1p; the first-global comparison of 4E-BP target mRNAs.
View Article and Find Full Text PDFBackground: The control of gene expression in eukaryotic cells occurs both transcriptionally and post-transcriptionally. Although many genes are now known to be regulated at the translational level, in general, the mechanisms are poorly understood. We have previously presented polysomal gradient and array-based evidence that translational control is widespread in a significant number of genes when yeast cells are exposed to a range of stresses.
View Article and Find Full Text PDFDriven by advances in mass spectrometry and analytical chemistry, coupled with the expanding number of completely sequenced genomes, proteomics is becoming a widely exploited technology for characterizing the proteins found in living systems. As proteomics becomes increasingly more high-throughput there is a parallel need for storage of the large quantities of data generated, to support data exchange and allow further analyses. The capture and storage of such data, along with subsequent release and dissemination, not only aid in sharing of the data throughout the proteomics community but also provide scientific insights into the observations between different laboratories, instruments, and software.
View Article and Find Full Text PDFDespite the growing volumes of proteomic data, integration of the underlying results remains problematic owing to differences in formats, data captured, protein accessions and services available from the individual repositories. To address this, we present the ISPIDER Central Proteomic Database search (http://www.ispider.
View Article and Find Full Text PDFGlobal inhibition of protein synthesis is a common response to stress conditions. We have analyzed the regulation of protein synthesis in response to oxidative stress induced by exposure to H(2)O(2) in the yeast Saccharomyces cerevisiae. Our data show that H(2)O(2) causes an inhibition of translation initiation dependent on the Gcn2 protein kinase, which phosphorylates the alpha-subunit of eukaryotic initiation factor-2.
View Article and Find Full Text PDFProteome science relies on bioinformatics tools to characterize proteins via their proteolytic peptides which are identified via characteristic mass spectra generated after their ions undergo fragmentation in the gas phase within the mass spectrometer. The resulting secondary ion mass spectra are compared with protein sequence databases in order to identify the amino acid sequence. Although these search tools (e.
View Article and Find Full Text PDFGlobal inhibition of protein synthesis is a hallmark of many cellular stress conditions. Even though specific mRNAs defy this (e.g.
View Article and Find Full Text PDF