Lamour, Nadia F.Wijesinghe, Dayanjan S.Mietla, Jennifer A.Ward, Katherine E.Stahelin, Robert V.Chalfant, Charles E.2025-07-232025-07-232011Lamour NF, Wijesinghe DS, Mietla JA, Ward KE, Stahelin RV, Chalfant CE. Ceramide kinase regulates the production of tumor necrosis factor α (TNFα) via inhibition of TNFα-converting enzyme. J Biol Chem. 2011;286(50):42808-42817. doi:10.1074/jbc.M111.310169https://hdl.handle.net/1805/49720Tumor necrosis factor α (TNFα) is a well known cytokine involved in systemic and acute inflammation. In this study, we demonstrate that ceramide 1-phosphate (C1P) produced by ceramide kinase (CERK) is a negative regulator of LPS-induced TNFα secretion. Specifically, bone marrow-derived macrophages isolated from CERK knock-out mice (CERK(-/-)) generated higher levels of TNFα than the wild-type mice (CERK(+/+)) in response to LPS. An increase in basal TNFα secretion was also observed in CERK(-/-) murine embryonic fibroblasts, which was rescued by re-expression of wild-type CERK. This effect was due to increased secretion and not transcription. The secretion of TNFα is regulated by TNFα-converting enzyme (TACE also known as ADAM17), and importantly, the activity of TACE was higher in cell extracts from CERK(-/-) as compared with wild type. In vitro analysis also demonstrated that C1P is a potent inhibitor of this enzyme, in stark contrast to ceramide and sphingosine 1-phosphate. Furthermore, TACE specifically bound C1P with high affinity. Finally, several putative C1P-binding sites were identified via homology throughout the protein sequence of TACE. These results indicate that C1P produced by CERK has a negative effect on the processing/secretion of TNFα via modulation of TACE activity.en-USAttribution-NonCommercial 4.0 InternationalLipidsLipid-binding proteinLipid synthesisSphingolipidTumor necrosis factor (TNF)Article