Identification of TFG- and autophagy-regulated proteins and glycerophospholipids in B cells shows a role for TFG in metabolism
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ABSTRACT: Autophagy supervises proteostasis and survival of plasma cells. TFG (Trk-fused gene) promotes autophagosome-lysosome flux in murine CH12 B cells, as well as their survival. Moreover, TFG is abundant in plasma cells. Hence, quantitative proteomics of CH12tfgKO and WT B cells in combination with lysosomal inhibition via NH4Cl should identify proteins that are prone to lysosomal degradation and contribute to autophagy, plasma cell biology and B cell survival. While lysosome inhibition via NH4Cl treatment unexpectedly reduced a number of proteins, it increased a large cluster of translational and ribosomal proteins, independent of TFG. The prosurvival protein BCL10 was decreased in CH12tfgKO B cells while the immunoglobulin JCHAIN was increased. Gene ontology analysis revealed that proteins 39 regulated by TFG alone, or in concert with lysosomes, localize to mitochondria and membrane 40 bounded organelles. Likewise, TFG regulated the abundance of metabolic enzymes, such as the glycolytic enzyme ALDOC and the short chain fatty acid activating enzyme ACOT9. To test for a function of TFG in lipid metabolism we performed shotgun lipidomics of glycerophospholipids. Total phosphatidylglycerol was more abundant in CH12tfgKO B cells. In contrast, several glycerophospholipid species, such as 36:2 phosphatidylethanolamine and 36:2 phosphatidylinositol, showed a dysequilibrium. Addition of phosphatidylglycerol elevated Cardiolipin in B cells. Hence, we propose a role for TFG in the regulation of proteins involved in survival and plasma cell biology, as well as in lipid homeostasis, mitochondrial functions and metabolism.
INSTRUMENT(S): Q Exactive
ORGANISM(S): Mus Musculus (mouse)
TISSUE(S): B Cell
SUBMITTER: Friedel Drepper
LAB HEAD: Bettina Warscheid
PROVIDER: PXD039180 | Pride | 2024-02-27
REPOSITORIES: Pride
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