Journal Article

Differential Effect of Actomyosin Relaxation on the Dynamic Properties of Focal Adhesion Proteins

Lavelin, Irena, Medalia, Ohad, Livne, Ariel, Kam, Zvi, Wolfenson, Haguy, Geiger, Benjamin, Henis, Yoav I., Volberg, Tova, Patla, Israel

2013

Overview

Treatment of cultured cells with inhibitors of actomyosin contractility induces rapid deterioration of stress fibers, and disassembly of the associated focal adhesions (FAs). In this study, we show that treatment with the Rho kinase inhibitor Y-27632, which blocks actomyosin contractility, induces disarray in the FA-associated actin bundles, followed by the differential dissociation of eight FA components from the adhesion sites. Live-cell microscopy indicated that the drug triggers rapid dissociation of VASP and zyxin from FAs (τ values of 7-8 min), followed by talin, paxillin and ILK (τ ~16 min), and then by FAK, vinculin and kindlin-2 (τ = 25-28 min). Examination of the molecular kinetics of the various FA constituents, using Fluorescence Recovery After Photobleaching (FRAP), in the absence of or following short-term treatment with the drug, revealed major changes in the kon and koff values of the different proteins tested, which are in close agreement with their differential dissociation rates from the adhesion sites. These findings indicate that mechanical, actomyosin-generated forces differentially regulate the molecular kinetics of individual FA-associated molecules, and thereby modulate FA composition and stability.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Actin / Actin Cytoskeleton - drug effects / Actin Cytoskeleton - metabolism / Actomyosin / Actomyosin - antagonists & inhibitors / Actomyosin - metabolism / Adhesion / Amides - pharmacology / Animals / Biology / Cell adhesion & migration / Cell culture / Cell Line / Contractility / Cytoskeleton / Deoxyribonucleic acid / Dismantling / Dissociation / DNA / Enzyme inhibitors / Extracellular matrix / Fluorescence / Fluorescence recovery after photobleaching / Focal adhesion kinase / Focal Adhesions - drug effects / Focal Adhesions - metabolism / Humans / ILK protein / Kinetics / Life sciences / Medical imaging / Metastasis / Microscopy / Muscle proteins / Neurobiology / Neurosciences / Paxillin / Photobleaching / Protein Kinase Inhibitors - pharmacology / Proteins / Pyridines - pharmacology / Rats / Rho-associated kinase / rho-Associated Kinases - antagonists & inhibitors / Talin / Vinculin