GTPase-activating protein that catalyzes the conversion of active GTP-bound Rho GTPases to their inactive GDP-bound form, thus suppressing various Rho GTPase-mediated cellular processes (PubMed:11432776). Also converts Cdc42 to an inactive GDP-bound state (PubMed:11432776). Essential for PTKB2 regulation of cytoskeletal organization via Rho family GTPases. Inhibits PAK2 proteolytic fragment PAK-2p34 kinase activity and changes its localization from the nucleus to the perinuclear region. Stabilizes PAK-2p34 thereby increasing stimulation of cell death (By similarity). Associates with MICAL1 on the endosomal membrane to promote Rab8-Rab10-dependent tubule extension. After dissociation with MICAL1, recruits WDR44 which connects the endoplasmic reticulum (ER) with the endosomal tubule, thereby participating in the export of a subset of neosynthesized proteins (PubMed:32344433).
