Role of p-21-activated kinases in cell survival and apoptotic pathways

A balance between cell survival and cell death is necessary for multicellul ar organisms to maintain: homeostasis. The family of p21-activated kinases (PAKs 1, 2, and 3) are Rho GTPase-regulated serine/threonine kinases implic ated in the regulation of a variety of cellular processes. The aim of this review is to describe two mechanisms by which PAKs can influence cellular h omeostasis. PAK2 is proteolytically cleaved and activated by caspases after stimulation of death receptors; this activation is implicated in the regul ation of biochemical and morphological changes during apoptosis. PAK1 is ac tivated by cell survival factors (for example, interleukin 3) and promotes survival via phosphorytation and inactivation of the pro-apoptotic Bcl-2 fa mily member Bad. Drug Dev. Res. 52:542-548, 2001. (C) 2001 Wiley-Liss, Inc.