Serine/threonine-protein kinase PAK 4 (PAK4)

Serine/threonine protein kinase that plays a role in a variety of different signaling pathways including cytoskeleton regulation, cell migration, growth, proliferation or cell survival. Activation by various effectors including growth factor receptors or active CDC42 and RAC1 results in a conformational change and another autophosphorylation on several serine and/or threonine residues.

Phosphorylates and inactivates the protein phosphatase SSH1, leading to increased inhibitory phosphorylation of the actin binding/depolymerizing factor cofilin. Reduced cofilin activity may lead to stabilization of actin filaments.