1
|
Steinmetz TD, Thomas J, Reimann L, Himmelreich AK, Schulz SR, Golombek F, Castiglione K, Jäck HM, Brodesser S, Warscheid B, Mielenz D. Identification of TFG- and Autophagy-Regulated Proteins and Glycerophospholipids in B Cells. J Proteome Res 2024; 23:1615-1633. [PMID: 38649144 DOI: 10.1021/acs.jproteome.3c00713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Autophagy supervises the proteostasis and survival of B lymphocytic cells. Trk-fused gene (TFG) promotes autophagosome-lysosome flux in murine CH12 B cells, as well as their survival. Hence, quantitative proteomics of CH12tfgKO and WT B cells in combination with lysosomal inhibition should identify proteins that are prone to lysosomal degradation and contribute to autophagy and B cell survival. Lysosome inhibition via NH4Cl unexpectedly reduced a number of proteins but increased a large cluster of translational, ribosomal, and mitochondrial proteins, independent of TFG. Hence, we propose a role for lysosomes in ribophagy in B cells. TFG-regulated proteins include CD74, BCL10, or the immunoglobulin JCHAIN. Gene ontology (GO) analysis reveals that proteins regulated by TFG alone, or in concert with lysosomes, localize to mitochondria and membrane-bound organelles. Likewise, TFG regulates the abundance of metabolic enzymes, such as ALDOC and the fatty acid-activating enzyme ACOT9. To test consequently for a function of TFG in lipid metabolism, we performed shotgun lipidomics of glycerophospholipids. Total phosphatidylglycerol is more abundant in CH12tfgKO B cells. Several glycerophospholipid species with similar acyl side chains, such as 36:2 phosphatidylethanolamine and 36:2 phosphatidylinositol, show a dysequilibrium. We suggest a role for TFG in lipid homeostasis, mitochondrial functions, translation, and metabolism in B cells.
Collapse
Affiliation(s)
- Tobit D Steinmetz
- Division of Molecular Immunology, Department of Internal Medicine 3, Nikolaus-Fiebiger-Zentrum, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, D-91054 Erlangen, Germany
| | - Jana Thomas
- Division of Molecular Immunology, Department of Internal Medicine 3, Nikolaus-Fiebiger-Zentrum, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, D-91054 Erlangen, Germany
| | - Lena Reimann
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, D-79104 Freiburg, Germany
| | - Ann-Kathrin Himmelreich
- Division of Molecular Immunology, Department of Internal Medicine 3, Nikolaus-Fiebiger-Zentrum, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, D-91054 Erlangen, Germany
| | - Sebastian R Schulz
- Division of Molecular Immunology, Department of Internal Medicine 3, Nikolaus-Fiebiger-Zentrum, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, D-91054 Erlangen, Germany
| | - Florian Golombek
- Chair of Bioprocess Engineering, Technical Faculty, FAU Erlangen-Nürnberg, D-91054 Erlangen, Germany
| | - Kathrin Castiglione
- Chair of Bioprocess Engineering, Technical Faculty, FAU Erlangen-Nürnberg, D-91054 Erlangen, Germany
| | - Hans-Martin Jäck
- Division of Molecular Immunology, Department of Internal Medicine 3, Nikolaus-Fiebiger-Zentrum, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, D-91054 Erlangen, Germany
- FAU Profile Center Immunomedicine (FAU I-MED), Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Schlossplatz 1, D-91054 Erlangen, Germany
| | - Susanne Brodesser
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Köln, D-50931 Köln, Germany
| | - Bettina Warscheid
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, D-79104 Freiburg, Germany
- Department of Biochemistry, Theodor Boveri-Institute, Biocenter, University of Würzburg, D-97074 Würzburg, Germany
| | - Dirk Mielenz
- Division of Molecular Immunology, Department of Internal Medicine 3, Nikolaus-Fiebiger-Zentrum, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, D-91054 Erlangen, Germany
- FAU Profile Center Immunomedicine (FAU I-MED), Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Schlossplatz 1, D-91054 Erlangen, Germany
| |
Collapse
|