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Ba, Q.

Publications and source records attributed to Ba, Q..

3 recordsLinked to original sources

Proteotype Co-evolution and Diversity in Mammals

Evolutionary profiling has been largely limited to the nucleotide level. Using consistent proteomic methods, we quantified proteomic and phosphoproteomic layers in fibroblasts from 11 common mammalian species, with transcriptomic variability as reference. The co-variation analysis indicates that transcript and protein expression robustness across mammals remarkably follows functional role, with extracellular matrix-associated expressions being most variable, demonstrating strong transcriptome-proteome co-evolution. Interestingly, the variability control of gene expression is universal at both inter-individual and inter-species scales, but of different extent. RNA metabolism processes particularly show the higher inter-species versus inter-individual variations. Our results further uncover that while ubiquitin-proteasome system is extremely conserved in mammals, the lysosome-mediated protein degradation exhibits a remarkable variation between mammalian lineages. Additionally, the phosphosite profiles reveals phosphorylation co-evolution network independent of protein abundance.

systems biology↗

Global impact of phosphorylation on protein endurance

Post-translational modifications such as phosphorylation can have profound effects on the physicochemical and biological properties of proteins. However, high-throughput and systematic approaches have not yet been developed to assess the effects of specific modification types and sites on protein lifetime, which represents a key parameter for understanding signaling rewiring and drug development. Here we describe a proteomic method, DeltaSILAC, to quantify the impact of site-specific phosphorylation on the endurance of thousands of proteins in live cells. Being configured on the reproducible data-independent acquisition mass spectrometry (DIA-MS), the pulse labeling approach using stable isotope-labeled amino acids in cells (SILAC), together with a novel peptide-level matching strategy, this multiplexed assay revealed the global delaying effect of phosphorylation on protein turnover in growing cancer cells. Further, we identified local sequence and structural features in proximity to the phosphorylated sites that could be associated with protein endurance alterations. We found that phosphorylated sites accelerating protein turnover are functionally selected for cell fitness and evolutionarily conserved. DeltaSILAC provides a generalizable approach for prioritizing the effects of phosphorylation sites on protein lifetime in the context of cell signaling and disease biology, which is highly complementary to existing methods. Finally, DeltaSILAC is widely applicable to diverse post-translational modification types and different cell systems.

systems biology↗

Whole-cell scale dynamic organization of lysosomes revealed by spatial statistical analysis

In eukaryotic cells, lysosomes are distributed in the cytoplasm as individual membrane-bound compartments to degrade macromolecules and to control cellular metabolism. A fundamental yet unanswered question is whether and, if so, how individual lysosomes are spatially organized so that their functions can be coordinated and integrated to meet changing needs of cells. To address this question, we analyze their collective behavior in cultured cells using spatial statistical techniques. We find that in single cells, lysosomes maintain nonrandom, stable, yet distinct spatial distributions, which are mediated by the coordinated effects of the cytoskeleton and lysosomal biogenesis on different lysosomal subpopulations. Furthermore, we find that throughout the intracellular space, lysosomes form dynamic clusters that substantially increase their interactions with endosomes. Together, our findings reveal the spatial organization of lysosomes at the whole-cell scale and provide new insights into how organelle interactions are mediated and regulated over the entire intracellular space.\n\nHighlightsO_LILysosomes maintain stable yet distinct spatial distributions in single cells\nC_LIO_LIThe cytoskeleton and lysosomal biogenesis mediate stable lysosomal distributions\nC_LIO_LILysosomes form dynamic clusters that promote their interactions with endosomes\nC_LIO_LITwo subpopulations of lysosomes jointly mediate formation of lysosomal clusters\nC_LI\n\neTOC BlurbLysosomes are spatially organized at the whole-cell scale and form dynamic clusters that promote their interactions with endosomes.

systems biology↗