We report the identification and characterization of a novel lipid kinase that phosphorylates
multiple substrates. This enzyme, which we term MuLK for multi-substrate lipid kinase, does
not belong to a previously described lipid kinase family. MuLK has orthologs in many
organisms and is broadly expressed in human tissues. Although predicted to be a soluble
protein, MuLK co-fractionates with membranes and localizes to an internal membrane
compartment. Recombinant MuLK phosphorylates diacylglycerol, ceramide, and 1 …