A novel C-terminal DxRSDxE motif in ceramide synthases involved in dimer formation.
| Autor: | Kim JL; Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel., Ben-Dor S; Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel., Rosenfeld-Gur E; Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel., Futerman AH; Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel. Electronic address: tony.futerman@weizmann.ac.il. |
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| Jazyk: | angličtina |
| Zdroj: | The Journal of biological chemistry [J Biol Chem] 2022 Feb; Vol. 298 (2), pp. 101517. Date of Electronic Publication: 2021 Dec 20. |
| DOI: | 10.1016/j.jbc.2021.101517 |
| Abstrakt: | Ceramide is a lipid moiety synthesized via the enzymatic activity of ceramide synthases (CerSs), six of which have been identified in mammalian cells, and each of which uses a unique subset of acyl-CoAs for ceramide synthesis. The CerSs are part of a larger gene family, the Tram-Lag-CLN8 domain family. Here, we identify a unique, C-terminal motif, the DxRSDxE motif, which is only found in CerSs and not in other Tram-Lag-CLN8 family members. Deletion of this motif in either CerS2 or in CerS6 did not affect the ability of either enzyme to generate ceramide using both an in vitro assay and metabolic labeling, but deletion of this motif did affect the activity of CerS2 when coexpressed with CerS6. Surprisingly, transfection of cells with either CerS2 or CerS6 lacking the motif did not result in changes in cellular ceramide levels. We found that CerS2 and CerS6 interact with each other, as shown by immunoprecipitation, but deletion of the DxRSDxE motif impeded this interaction. Moreover, proteomics analysis of cells transfected with CerS6 Δ338-344 indicated that deletion of the C-terminal motif impacted cellular protein expression, and in particular, the levels of ORMDL1, a negative regulator of sphingolipid synthesis. We suggest that this novel C-terminal motif regulates CerS dimer formation and thereby impacts ceramide synthesis. Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article. (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.) |
| Databáze: | MEDLINE |
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