title: RhoA and ROCK promote migration by limiting membrane protrusions.
abstract: Previously, we and others have shown that RhoA and ROCK signaling are required for negatively regulating integrin-mediated adhesion and for tail retraction of migrating leukocytes. This study continues our investigation into the molecular mechanisms underlying RhoA/ROCK-regulated integrin adhesion. We show that inhibition of ROCK up-regulates integrin-mediated adhesion, which is accompanied by both increased phosphotyrosine signaling through Pyk-2 and paxillin and inappropriate membrane protrusions. We provide evidence that inhibition of ROCK induces integrin adhesion by promoting remodeling of the actin cytoskeleton. Furthermore, we find that ROCK regulates membrane activity through a pathway involving cofilin. Inhibition of RhoA signaling allows the formation of multiple competing lamellipodia that disrupt productive migration of monocytes. Together, our results show that RhoA/ROCK signaling promotes migration by restricting integrin activity and membrane protrusions to the leading edge.
authors.affiliation: Department of Cell and Developmental Biology, Lineberger Comprehensive Cancer Center and Comprehensive Center for Inflammatory Disorders, University of North Carolina, Chapel Hill, North Carolina 27599, USA. becky_worthlake@med.unc.edu
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Worthylake
authors.forename: Keith
authors.initials: K
authors.lastname: Burridge
mesh_terms: D000577:Amides / Q000494:pharmacology; D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology* / Q000648:ultrastructure; D002465:Cell Movement / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016023:Integrins / Q000502:physiology; D047908:Intracellular Signaling Peptides and Proteins; D009000:Monocytes / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D011725:Pyridines / Q000494:pharmacology; D015398:Signal Transduction / Q000502:physiology*; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein / Q000502:physiology*
chemical_list: D000577:Amides; D004791:Enzyme Inhibitors; D016023:Integrins; D047908:Intracellular Signaling Peptides and Proteins; D011725:Pyridines; C108830:Y 27632; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein