Overview:

PAK proteins is a family of serine/threonine kinases that serve as targets for the small GTP binding proteins, CDC42 and RAC1, and have been implicated in a wide range of biological activities. The p21 activated kinases (PAK) are critical effectors that link Rho GTPases to cytoskeleton reorganization and nuclear signaling. PAK2 is activated by proteolytic cleavage during caspase-mediated apoptosis, and may play a role in regulating the apoptotic events in the dying cell (1). The CDC42 and RAC1 induce autophosphorylation of PAK2, which stimulates sustained phosphorylation of other substrates (2).

References:

1. Koeppel, M. A. et.al: Identification and characterization of PS-GAP as a novel regulator of caspase-activated PAK-2. J. Biol. Chem. 279: 53653-53664, 2004. 2. Martin, G. A. et.al: A novel serine kinase activated by rac1/CDC42Hs-dependent autophosphorylation is related to PAK65 and STE20. EMBO J. 14: 1970-1978, 1995.