This domain is found at the C terminus of ceramide kinases (CERKs) from eukaryotes. This domain is related to the beta sandwich domain of NAD kinases. Along with the N-terminal domain, it catalyses specifically the phosphorylation of ceramide to form ceramide 1-phosphate [, , , ]. Ceramide is a critical sphingolipid metabolite that induces programmed cell death (PCD), while ceramide-1-phosphate has a PCD suppressive effect. Thus, ceramide phosphorylation plays a role in the modulation of PCD, and the CERK activity is crucial for the maintenance of cell viability [, ]. This domain can also be found in human ceramide kinase-like protein that has no detectable ceramide-kinase activity [].
