Plays a key role in phospholipid biosynthesis by catalyzing the phosphorylation of free choline to phosphocholine, the first step in phosphatidylcholine biosynthesis ( ). Also phosphorylates ethanolamine, thereby contributing to phosphatidylethanolamine biosynthesis (, ). Has higher activity with choline (, ). May contribute to tumor cell growth .
This isoform plays a key role in lipolysis of lipid droplets following glucose deprivation . In response to glucose deprivation, phosphorylated by AMPK, promoting localization to lipid droplets . Phosphorylation is followed by acetylation by KAT5, leading to dissociation of the homodimer into a monomer . Monomeric CHKA isoform 1 is converted into a tyrosine-protein kinase, which phosphorylates lipid droplet structural proteins PLIN2 and PLIN3, leading to lipolysis of lipid droplets .
Subcellular locations: Cytoplasm, Cytosol
Subcellular locations: Lipid droplet
Isoform 1 localizes to lipid droplets following phosphorylation by AMPK.