An ADP-Ribosylation Factor GTPase-activating Protein Git2-short/KIAA0148 Is Involved in Subcellular Localization of Paxillin and Actin Cytoskeletal Organization

• DOI: 10.1091/mbc.12.3.645
• Publication Date: 2013-07-03T00:09:59Z
• Authors: Yuichi Mazaki; Shigeru Hashimoto; Katsuya Okawa; Asako Tsubouchi; Kuniaki Nakamura; Ryohei Yagi; Hajime Yano; Akiko Kondo; Akihiro Iwamatsu; Akira Mizoguchi; Hisataka Sabe
• Keywords: Paxillin; PTK2

Paxillin acts as an adaptor protein in integrin signaling. We have shown that paxillin exists a relatively large cytoplasmic pool, including perinuclear areas, addition to focal complexes formed at the cell periphery and adhesions underneath cell. Several ADP-ribosylation factor (ARF) GTPase-activating proteins (GAPs; ARFGAPs) been associate with paxillin. report here Git2-short/KIAA0148 exhibits properties of paxillin-associated ARFGAP appears be colocalized paxillin, primarily areas. A fraction Git2-short was also localized actin-rich structures periphery. Unlike however, did not accumulate is short isoform Git2, which highly homologous p95PKL, another paxillin-binding protein, showed weaker binding affinity toward than Git2. The activities Git2 previously demonstrated vitro, we provided evidence least one ARF isoform, ARF1, intracellular substrate for GAP activity Git2-short. could antagonize several known ARF1-mediated phenotypes: overexpression Git2-short, but its GAP-inactive mutant, caused redistribution Golgi beta-COP reduced amounts paxillin-containing actin stress fibers. Perinuclear localization sensitive inactivation, affected by overexpression. On other hand, unaffected or even augmented Therefore, weakly interacting pleiotropic functions involving regulation organization, cytoskeletal subcellular all need coordinately regulated during integrin-mediated adhesion