期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:2001
卷号:98
期号:26
页码:14865-14870
DOI:10.1073/pnas.251249298
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Abl family nonreceptor tyrosine kinases regulate cellular morphogenesis and motility through functional interactions with the actin cytoskeleton. Although Abl family kinases are known to contain filamentous (F)-actin-binding domains at their C termini, it is unclear how Abl family kinases regulate the structure and/or function of the actin cytoskeleton. We show here that the Abl-related kinase Arg binds with positive cooperativity to F-actin in vitro with binding saturating at a ratio of one Arg/two actin molecules. Measurements of the F-actin-binding properties of Arg deletion mutants led to the identification of a second, previously uncharacterized internal F-actin-binding domain in Arg. Purified Arg can bundle F-actin in vitro, and this bundling activity requires both F-actin-binding domains. An Arg-yellow fluorescent protein fusion protein can induce the formation of actin-rich structures at the lamellipodia of Swiss 3T3 fibroblasts. Both of Arg's F-actin-binding domains are necessary and sufficient for the formation of these actin-rich structures. Together, our data suggest that Arg can use its F-actin-bundling activity to directly regulate actin cytoskeletal structure in vivo.