Cloned (Comment) | Organism |
---|---|
gene CERS1, recombinant overexpression in HEK cells, FTY720 inhibits CerS1 activity to a greater extent than CerS5 in the overexpressing cells | Homo sapiens |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
FTY720 | inhibits ceramide synthases and upregulates dihydrosphingosine 1-phosphate formation in human lung endothelial cells. FTY720 is a sphingosine analogue and in clinical trials as an immunomodulator. Multifaceted mode of interaction between FTY720 and CerS. FTY720 inhibits ceramide synthesis using C18-CoA to a greater extent than other acyl-CoAs, dependence on acyl-CoA chain length of inhibition of CerS activity by FTY720. Sphinganine first binds to CerS to form an E-S (CerS-sphinganine) complex, and only after formation of this complex can FTY720 bind. The binding sites of FTY720 and acyl-CoA appear to be distinct, but the interaction between sphinganine binding and FTY720 binding nevertheless impacts the rate of the reaction with respect to acyl-CoA. FTY720 inhibits ceramide synthesis at high sphinganine concentrations in vivo, but not at low concentrations, supporting a complex, possibly allosteric mode of interaction between sphinganine and FTY720 and is consistent with uncompetitive inhibitors being most effective at high substrate concentrations. FTY720 acts as a noncompetitive inhibitor toward C18-CoA. The inhibition of FTY720 toward C18-CoA is allosteric under the normal reaction conditions. Sphingolipid composition of HEK cells treated with FTY720, overview | Homo sapiens | |
fumonisin B1 | - |
Homo sapiens | |
additional information | in contrast to the dual effects of fumonisin B1, which is only observed in cells overexpressing CerS, FTY720 elevates ceramide levels in untransfected cells | Homo sapiens |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | activates | Homo sapiens |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
sphinganine + stearoyl-CoA | Homo sapiens | - |
N-stearoylsphinganine + CoA | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | P27544 | - |
- |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
erythrocyte | - |
Homo sapiens | - |
HEK-293T cell | - |
Homo sapiens | - |
lung | - |
Homo sapiens | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
sphinganine + stearoyl-CoA | - |
Homo sapiens | N-stearoylsphinganine + CoA | - |
? |
Synonyms | Comment | Organism |
---|---|---|
ceramide synthase 1 | - |
Homo sapiens |
CerS1 | - |
Homo sapiens |
General Information | Comment | Organism |
---|---|---|
malfunction | upon incubation of HEK cells with inhibitor FTY720, an increase in ceramide levels is observed, with no change in endogenous sphinganine levels. Similar increases are observed for hexosylceramide and sphingomyelin. Moreover, levels of C18-C22-ceramide are significantly increased, as are levels of C18-C22-hexosylceramide and C18-C22-sphingomyelin. This result is consistent with a complex mode of interaction of FTY720 with CerS, perhaps involving an allosteric element that is not preserved in vitro, whereby ceramide synthesis is stimulated in cells despite its inhibition by FTY720 in vitro | Homo sapiens |