Catalytic domain of the Serine/Threonine Kinases, Cyclin-Dependent protein Kinase Like 2 and 3
STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. CDKL2, also called p56 KKIAMRE, is expressed in testis, kidney, lung, and brain. It functions mainly in mature neurons and plays an important role in learning and memory. Inactivation of CDKL3, also called NKIAMRE (NKIATRE in rat), by translocation is associated with mild mental retardation. It has been reported that CDKL3 is lost in leukemic cells having a chromosome arm 5q deletion, and may contribute to the transformed phenotype. CDKs belong to a large family of STKs that are regulated by their cognate cyclins. Together, they are involved in the control of cell-cycle progression, transcription, and neuronal function. The CDKL2/3 subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.