Fibronectin Matrix Assembly Requires Distinct Contributions from Rho Kinases I and -II
- 1 January 2007
- journal article
- Published by American Society for Cell Biology (ASCB) in Molecular Biology of the Cell
- Vol. 18 (1) , 66-75
- https://doi.org/10.1091/mbc.e06-08-0684
Abstract
Extracellular matrix is integral to tissue architecture and regulates many aspects of cell behavior. Fibronectin matrix assembly involves the actin cytoskeleton and the small GTPase RhoA, but downstream signaling is not understood. Here, down-regulation of either rho kinase isoform (ROCK I or -II) by small interfering RNA treatment blocked fibronectin matrix assembly, although the phenotypes were distinct and despite persistence of the alternate kinase. Remnant fibronectin on ROCK-deficient fibroblasts was mostly punctate and more deoxycholate soluble compared with controls. Fibronectin matrix assembly defects in ROCK-deficient cells did not result from decreased synthesis/secretion, altered fibronectin mRNA splicing, metalloproteinase activity, or α5β1 integrin dysfunction. Rescue could be effected by ROCK protein restoration or phosphomimetic myosin light chain expression. However, the effect of ROCK I deficiency on fibronectin matrix assembly was secondary to altered cell surface morphology, rich in filopodia, resulting from high GTP–Cdc42 levels. Total internal reflection microscopy revealed that a submembranous pool of myosin light chain in control cells was missing in ROCK II-deficient cells and replaced by stress fibers. Together, two rho kinases contribute to fibronectin matrix assembly in a different manner and cortical myosin II-driven contractility, but not stress fibers, may be critical in this activity.Keywords
This publication has 44 references indexed in Scilit:
- Decreased Perivascular Fibrosis but Not Cardiac Hypertrophy in ROCK1 +/− Haploinsufficient MiceCirculation, 2005
- Rho GTPases in cell biologyNature, 2002
- ROCK and mDia1 antagonize in Rho-dependent Rac activation in Swiss 3T3 fibroblastsThe Journal of cell biology, 2002
- Regulatory Role for Src and Phosphatidylinositol 3-Kinase in Initiation of Fibronectin Matrix AssemblyJournal of Biological Chemistry, 2002
- Basement membrane proteoglycans in glomerular morphogenesis: chondroitin sulfate proteoglycan is temporally and spatially restricted during development.Journal of Histochemistry & Cytochemistry, 1993
- Inhibition of binding of fibronectin to matrix assembly sites by anti-integrin (alpha 5 beta 1) antibodies.The Journal of cell biology, 1990
- Selective secretion of alternatively spliced fibronectin variants.The Journal of cell biology, 1989
- Monoclonal antibody to fibronectin which inhibits extracellular matrix assemblyFEBS Letters, 1987
- Binding of plasma fibronectin to cell layers of human skin fibroblasts.The Journal of cell biology, 1983
- Cytochalasin B releases a major surface-associated glycoprotein, fibronectin, from cultured fibroblastsExperimental Cell Research, 1978