title: Src-dependent phosphorylation of ROCK participates in regulation of focal adhesion dynamics.
abstract: When a cell migrates, the RhoA-ROCK-mediated contractile signal is suppressed in the leading edge to allow dynamic adhesions for protrusion. However, several studies have reported that RhoA is indeed active in the leading edge of a migrating cell during serum stimulation. Here, we present evidence that regulation of ROCKII phosphorylation at the Y722 site in peripheral focal contacts is crucial for controlling the turnover of the focal adhesion (FA) complex uncoupled from RhoA activation during serum-stimulated migration. However, this phosphorylation control is dispensable for migration when RhoA is downregulated in cells treated with platelet-derived growth factor (PDGF). We further present evidence that ROCKII is phosphorylated by Src in FAs and this phosphorylation event decreases RhoA binding activity of ROCKII. Lack of this regulatory control leads to sustained myosin-mediated contractility and FA elongation during lysophosphatidic acid (LPA) stimulation. Altogether, our data suggest that Src-dependent ROCKII phosphorylation provides a means of tuning contractility required for FAs dynamics when RhoA is active.
authors.affiliation: Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 112, Taiwan.
authors.forename: Hsiao-Hui
authors.initials: HH
authors.lastname: Lee
authors.forename: Sui-Chih
authors.initials: SC
authors.lastname: Tien
authors.forename: Tzuu-Shuh
authors.initials: TS
authors.lastname: Jou
authors.forename: Yuan-Chen
authors.initials: YC
authors.lastname: Chang
authors.forename: Jheng-Guang
authors.initials: JG
authors.lastname: Jhong
authors.forename: Zee-Fen
authors.initials: ZF
authors.lastname: Chang
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000235:genetics; D015536:Down-Regulation; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D022001:Focal Adhesions / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D007211:Indoles / Q000494:pharmacology; D051379:Mice; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism*; D041681:NIH 3T3 Cells; D010766:Phosphorylation / Q000187:drug effects / Q000235:genetics; D010982:Platelet-Derived Growth Factor / Q000378:metabolism; D013449:Sulfonamides / Q000494:pharmacology; D019076:Transgenes / Q000235:genetics; D054460:rho-Associated Kinases / Q000235:genetics / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*; D019061:src-Family Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D007211:Indoles; D050505:Mutant Proteins; D010982:Platelet-Derived Growth Factor; C416927:SU 6656; D013449:Sulfonamides; D019061:src-Family Kinases; C515852:ROCK2 protein, human; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein