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- Gnann, Christian, et al.
(författare)
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Widespread enzyme expression variations underlie diverse metabolic capacities within cell types
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Metabolic enzymes perform life-sustaining functions in various compartments of the cell. Recent studies have shown some enzymes to exhibit varied expression or localization between genetically identical cells and that this heterogeneity impacts drug resistance, metastasis, differentiation, and immune cell activation. However, no systematic analysis of metabolic cellular heterogeneity has been performed. Here, we leverage imaging-based single-cell spatial proteomic data to reveal the extent of non-genetic partitioning of the metabolic proteome. Over half of all enzymes localize to multiple cellular compartments, hinting at moonlighting potential. In addition, nearly two fifths of metabolic enzymes exhibit cell-to-cell variable expression. We demonstrate that individual cells reproduce these highly heterogeneous cell populations using clonal expansion, establishing that cells recapitulate myriad metabolic phenotypes over just a few cell divisions. To identify multifunctional moonlighting enzymes, we mine protein-protein interaction datasets to find interacting proteins with distinct functional roles, and using a timeresolved transcriptomic dataset, we find that metabolic heterogeneity arises largely independently of cell cycle progression and is established mostly post-transcriptionally or posttranslationally. Taken together, our data suggest that the heterogeneity of metabolic enzymes establish diverse cellular phenotypes, which are reflected in tissues, and which may ultimately allow targeted studies of their roles in health and disease.
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- Karlsson, Max, et al.
(författare)
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Genome-wide single cell annotation of the human protein-coding genes
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- An important quest for the life science community is to deliver a complete annotation of the human building-blocks of life, the genes and the proteins. Here, we report on a genome-wide effort to annotate all protein-coding genes based on single cell transcriptomics data representing all major tissues and organs in the human body, integrated with data from bulk transcriptomics and antibody-based tissue profiling. Altogether, 25 tissues have been analyzed with single cell transcriptomics resulting in genome-wide expression in 444 single cell types using a strategy involving pooling data from individual cells to obtain genome-wide expression profiles of individual cell type. We introduce a new genome-wide classification tool based on clustering of similar expression profiles across single cell types, which can be visualized using dimensional reduction maps (UMAP). The clustering classification is integrated with a new “tau” score classification for all protein-coding genes, resulting in a measure of single cell specificity across all cell types for all individual genes. The analysis has allowed us to annotate all human protein-coding genes with regards to function and spatial distribution across individual cell types across all major tissues and organs in the human body. A new version of the open access Human Protein Atlas (www.proteinatlas.org) has been launched to enable researchers to explore the new genome-wide annotation on an individual gene level.
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- Mahdessian, Diana, et al.
(författare)
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Profiling the human cytoplasmic proteome.
- 2016
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Ingår i: Molecular Biology of the Cell. - : AMER SOC CELL BIOLOGY. - 1059-1524 .- 1939-4586. ; 27
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Tidskriftsartikel (refereegranskat)
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- Mahdessian, Diana, et al.
(författare)
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Spatiotemporal characterization of the human proteome.
- 2017
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Ingår i: Molecular Biology of the Cell. - : The American Society for Cell Biology - ASCB. - 1059-1524 .- 1939-4586. ; 28
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 8. |
- Mahdessian, Diana, et al.
(författare)
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Spatiotemporal dissection of the cell cycle with single-cell proteogenomics
- 2021
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Ingår i: Nature. - : Springer Nature. - 0028-0836 .- 1476-4687. ; 590:7847
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Tidskriftsartikel (refereegranskat)abstract
- Spatial and temporal variations among individual human cell proteomes are comprehensively mapped across the cell cycle using proteomic imaging and transcriptomics. The cell cycle, over which cells grow and divide, is a fundamental process of life. Its dysregulation has devastating consequences, including cancer(1-3). The cell cycle is driven by precise regulation of proteins in time and space, which creates variability between individual proliferating cells. To our knowledge, no systematic investigations of such cell-to-cell proteomic variability exist. Here we present a comprehensive, spatiotemporal map of human proteomic heterogeneity by integrating proteomics at subcellular resolution with single-cell transcriptomics and precise temporal measurements of individual cells in the cell cycle. We show that around one-fifth of the human proteome displays cell-to-cell variability, identify hundreds of proteins with previously unknown associations with mitosis and the cell cycle, and provide evidence that several of these proteins have oncogenic functions. Our results show that cell cycle progression explains less than half of all cell-to-cell variability, and that most cycling proteins are regulated post-translationally, rather than by transcriptomic cycling. These proteins are disproportionately phosphorylated by kinases that regulate cell fate, whereas non-cycling proteins that vary between cells are more likely to be modified by kinases that regulate metabolism. This spatially resolved proteomic map of the cell cycle is integrated into the Human Protein Atlas and will serve as a resource for accelerating molecular studies of the human cell cycle and cell proliferation.
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- Skogs, Marie, et al.
(författare)
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Antibody Validation in Bioimaging Applications Based on Endogenous Expression of Tagged Proteins
- 2017
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 16:1, s. 147-155
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Tidskriftsartikel (refereegranskat)abstract
- Antibodies are indispensible research tools, yet the scientific community has not adopted standardized procedures to validate their specificity. Here we present a strategy to systematically validate antibodies for immunofluorescence (IF) applications using gene tagging. We have assessed the on- and off-target binding capabilities of 197 antibodies using 108 cell lines expressing EGFP-tagged target proteins at endogenous levels. Furthermore, we assessed batch-to-batch effects for 35 target proteins, showing that both the on- and off-target binding patterns vary significantly between antibody batches and that the proposed strategy serves as a reliable procedure for ensuring reproducibility upon production of new antibody batches. In summary, we present a systematic scheme for antibody validation in IF applications using endogenous expression of tagged proteins. This is an important step toward a reproducible approach for context- and application-specific antibody validation and improved reliability of antibody-based experiments and research data.
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