CLK4, Active

CLK4 or CDC-like kinase 4 belongs to the CDC2-like protein kinase (CLK) family that can interact with and phosphorylate the serine- and arginine-rich (SR) proteins. The SR proteins are known to play an important role in the formation of spliceosomes and thus may be involved in the regulation of alternative splicing. CLK4 expressed in E. coli phosphorylated myelin basic protein as a substrate as well as autophosphorylating itself but it did not phosphorylate H2B (1).