Phosphorylation of the cytoskeletal protein CAP1 controls its association with cofilin and actin

摘要: Cell signaling can control the dynamic balance between filamentous and monomeric actin by modulating regulatory proteins. One family of regulating proteins that controls dynamics comprises cyclase-associated 1 2 (CAP1 2, respectively). However, cell signals regulate CAPs remained unknown. We mapped phosphorylation sites on mouse CAP1 found S307 S309 to be sites. further identified glycogen synthase kinase 3 as a phosphorylating S309. The phosphomimetic mutant S307D/S309D lost binding its partner cofilin and, when expressed in cells, caused accumulation stress fibers similar cells with reduced CAP expression. In contrast, non-phosphorylatable S307A/S309A showed drastically increased actin. These results suggest serves facilitate release for subsequent cycle filament severing. Moreover, our function tandem; neither alterations and/or actin, nor defects rescuing phenotype enlarged size knockdown was observed point mutants either or summary, we identify novel mechanism through phosphorylation.