Project description:Defining the subcellular distribution of all human proteins and its remodeling across cellular states remains a central goal in cell biology. Here, we present a high-resolution strategy to map subcellular organization using organelle immuno-capture coupled to mass spectrometry. We apply this workflow to a cell-wide collection of membranous and membrane-less compartments. A graph-based analysis reveals the subcellular localization of over 7,600 proteins, defines spatial networks, and uncovers interconnections between cellular compartments. Our approach can be deployed to comprehensively profile proteome remodeling during cellular perturbation. By characterizing the cellular landscape following hCoV-OC43 viral infection, we discover that many proteins are regulated by changes in their spatial distribution rather than by changes in abundance. Our results establish that proteome-wide analysis of subcellular remodeling provides unique insights for the elucidation of cellular responses, uncovering an essential role for ferroptosis in OC43 infection. Our dataset can be explored at organelles.czbiohub.org.
Project description:Defining the subcellular distribution of all human proteins and its remodeling across cellular states remains a central goal in cell biology. Here, we present a high-resolution strategy to map subcellular organization using organelle immuno-capture coupled to mass spectrometry. We apply this proteomics workflow to a cell-wide collection of membranous and membrane-less compartments. A graph-based representation of our data reveals the subcellular localization of over 7,600 proteins, defines spatial protein networks, and uncovers interconnections between cellular compartments. We demonstrate that our approach can be deployed to comprehensively profile proteome remodeling during cellular perturbation. By characterizing the cellular landscape following hCoV-OC43 viral infection, we discover that many proteins are regulated by changes in their spatial distribution rather than by changes in their total abundance. Our results establish that proteome-wide analysis of subcellular remodeling provides essential insights for the elucidation of cellular responses. Our dataset can be explored at organelles.czbiohub.org.
Project description:Cell cycle progression relies on coordinated changes in the composition and subcellular localization of the proteome. By applying two distinct convolutional neural networks on images of millions of live yeast cells, we resolved proteome-level dynamics in both concentration and localization during the cell cycle, with resolution of ~20 subcellular localization classes. We show that a quarter of the proteome displays cell cycle periodicity, with proteins tending to be controlled either at the level of localization or concentration, but not both. Distinct levels of protein regulation are preferentially utilized for different aspects of the cell cycle, with changes in protein concentration being mostly involved in cell cycle control, while changes in protein localization in the biophysical implementation of the cell cycle program. We present a resource for exploring global proteome dynamics during the cell cycle, which will aid in understanding a fundamental biological process at a systems level.
Project description:We introduce APEX-seq, a method for RNA sequencing based on direct proximity labeling of RNA using the peroxidase enzyme APEX2. APEX-seq in nine distinct subcellular locales produced a nanometer-resolution spatial map of the human transcriptome as a resource, revealing extensive patterns of localization for diverse RNA classes and transcript isoforms. We uncover a radial organization of the nuclear transcriptome, which is gated at the inner surface of the nuclear pore for cytoplasmic export of processed transcripts. We identify two distinct pathways of messenger RNA localization to mitochondria, each associated with specific sets of transcripts for building complementary macromolecular machines within the organelle. APEX-seq should be widely applicable to many systems, enabling comprehensive investigations of the spatial transcriptome.
Project description:The key role of RNA-binding proteins (RBPs) in posttranscriptional regulation of gene expression is intimately tied to their subcellular localization. Dysregulated localization may severely disrupt the biological functions of RBPs. To reveal the regulatory mechanisms of RBPs, methods for systematically mapping the subcellular localized RBPs and monitoring their translocations under physiological conditions are in high demand. Herein, a subcellular-specific RNA labeling method was developed for efficient enrichment and deep profiling of nuclear and cytoplasmic RBPs. A total of 1221 nuclear RBPs and 1333 cytoplasmic RBPs were enriched and identified using nuclear/cytoplasm targeting enrichment probes, which represented an increase of 54.4% and 85.7% compared with previous reports. The probes were further applied in the first omics-level investigation of subcellular-specific RBP-RNA interactions upon ferroptosis induction. Interestingly, large-scale RBPs displayed enhanced interaction with RNAs in nucleus but reduced association with RNAs in cytoplasm during ferroptosis process. Among these RBPs with regulated RNA-binding, translation was found as one of the commonly enriched GO functions by different ferroptosis inducers, indicating ferroptosis could disturb protein translation via different pathways. Furthermore, we discovered dozens of nucleoplasmic translocation candidate RBPs upon ferroptosis induction and validated representative ones by immunofluorescence imaging. The enrichment of TCA cycle in the translocation candidate RBPs may provide new insights for investigating their possible roles in ferroptosis induced metabolism dysregulation. The above findings suggest the potential of our enrichment method for high-throughput RBP mapping with organelle-level spatial resolution.
Project description:RNA localization and local translation are important biological processes that underlie establishment of body axis, cell migration and synaptic plasticity. However, it is unclear to which extent mRNA localization contributes toward local proteome and how much of protein localization is achieved via protein transport or local translation of uniformly distributed mRNAs. To address this question, we performed genome-wide analysis of the local proteome, transcriptome, and translation rates in neurites and cell bodies of neurons differentiated from mouse embryonic stem cells.
Project description:RNA localization and local translation are important biological processes that underlie establishment of body axis, cell migration and synaptic plasticity. However, it is unclear to which extent mRNA localization contributes toward local proteome and how much of protein localization is achieved via protein transport or local translation of uniformly distributed mRNAs. To address this question, we performed genome-wide analysis of the local proteome, transcriptome, and translation rates in neurites and cell bodies of neurons differentiated from mouse embryonic stem cells.
Project description:The distribution of RNA in human embryonic stem cells (hESC) and the function of RNA localization in maintaining hESC pluripotency and differentiation are currently unknown. Here, by isolating five subcellular components of hESCs and differentiated cells, we uncovered the global subcellular RNA localization in hESC. For protein-coding mRNA, different transcripts of the same gene exhibit an “isoform switch” between subcellular components, which is regulated by localization cis-elements in their variable regions. For noncoding RNA, multiple sequence features such as polyA tail, length, and GC content jointly regulate their subcellular localization. In addition, we found that some developmental genes can be transcribed in advance and confined to chromatin in undifferentiated hESCs. Finally, we revealed significant changes in overall RNA distribution, mapped RNA dynamic localization atlas, and characterized different dynamic RNA localization patterns during hESC differentiation into mesoderm. The multiple RNA localization patterns we revealed will provide some new enlightenment for hESC stemness maintenance and differentiation.