Sphingomyelin phosphodiesterase 2; Converts sphingomyelin to ceramide. Hydrolyze 1-acyl-2-lyso- sn-glycero-3-phosphocholine (lyso-PC) and 1-O-alkyl-2-lyso-sn-glycero- 3-phosphocholine (lyso-platelet-activating factor). The physiological substrate seems to be Lyso-PAF; Belongs to the neutral sphingomyelinase family.

Sphingomyelin phosphodiesterase; Converts sphingomyelin to ceramide. Also has phospholipase C activities toward 1,2-diacylglycerolphosphocholine and 1,2-diacylglycerolphosphoglycerol. Isoform 3 lacks residues that bind the cofactor Zn(2+) and has no enzyme activity; Belongs to the acid sphingomyelinase family.

Phosphatidylcholine:ceramide cholinephosphotransferase 1; Sphingomyelin synthases synthesize the sphingolipid, sphingomyelin, through transfer of the phosphatidyl head group, phosphatidylcholine, on to the primary hydroxyl of ceramide. The reaction is bidirectional depending on the respective levels of the sphingolipid and ceramide. Golgi apparatus SMS1 directly and specifically recognizes the choline head group on the substrate, requiring two fatty chains on the choline-P donor molecule in order to be recognized efficiently as a substrate. Major form in macrophages. Required for cell [...]

Ectonucleotide pyrophosphatase/phosphodiesterase family member 7; Converts sphingomyelin to ceramide and phosphocholine. Has also phospholipase C activity and can cleave phosphocholine from palmitoyl lyso-phosphatidylcholine. Does not have nucleotide pyrophosphatase activity. Belongs to the nucleotide pyrophosphatase/phosphodiesterase family.

Phosphatidylcholine:ceramide cholinephosphotransferase 2; Sphingomyelin synthases synthesize the sphingolipid, sphingomyelin, through transfer of the phosphatidyl head group, phosphatidylcholine, on to the primary hydroxyl of ceramide. The reaction is bidirectional depending on the respective levels of the sphingolipid and ceramide. Plasma membrane SMS2 can also convert phosphatidylethanolamine (PE) to ceramide phosphatidylethanolamine (CPE). Major form in liver. Required for cell growth in certain cell types. Regulator of cell surface levels of ceramide, an important mediator of signa [...]

Ceramide synthase 2; Ceramide synthase that catalyzes formation of ceramide from sphinganine and acyl-CoA substrates, with high selectivity toward very- long (C22:0-C24:0) chain as acyl donor.

Sphingolipid delta(4)-desaturase DES1; Has sphingolipid-delta-4-desaturase activity. Converts D- erythro-sphinganine to D-erythro-sphingosine (E-sphing-4-enine). Belongs to the fatty acid desaturase type 1 family. DEGS subfamily.

Ceramide synthase 6; Ceramide synthase that catalyzes formation of ceramide from sphinganine and acyl-CoA substrates, with high selectivity toward palmitoyl-CoA (hexadecanoyl-CoA; C16:0-CoA) as acyl donor. Can use other acyl donors, but with less efficiency (By similarity). Ceramides generated by CERS6 play a role in inflammatory response (By similarity). Acts as a regulator of metabolism and hepatic lipid accumulation (By similarity). Under high fat diet, palmitoyl- (C16:0-) ceramides generated by CERS6 specifically bind the mitochondrial fission factor MFF, thereby promoting mitochon [...]

Sphingolipid delta(4)-desaturase/C4-monooxygenase DES2; Bifunctional enzyme which acts as both a sphingolipid delta(4)-desaturase and a sphingolipid C4-monooxygenase.