ROCK-II-induced membrane blebbing and chromatin condensation require actin cytoskeleton.
Ectopic expression of ROCK II (Rho kinase II or ROKalpha), an effector of Rho GTPase, induces membrane blebbing and chromatin condensation. ROCK II can induce membrane blebbing in the presence of the caspase inhibitor z-VAD-fmk or in caspase-3-deficient MCF-7 cells, indicating that the activation of caspases is not required. ROCK-II-induced membrane blebbing, however, is reversed by the myosin light chain kinase inhibitor ML-7 or cytochalasin D. In addition, the expression of a constitutively activated form of cofilin (S3A-cofilin) suppresses both membrane blebbing and chromatin condensation in ROCK II expressing cells. These findings suggest that the activation of actin-myosin contractility is responsible for membrane blebbing and chromatin condensation and implicate ROCK II as a potential mediator of the morphological changes associated with apoptosis.
Department of Medicine, Microbiology, Immunology, and Molecular Genetics, UCLA School of Medicine, Los Angeles, California 900095-1678, USA.
Yuhong
Y
Song
Bao Q
BQ
Hoang
David D
DD
Chang
D008841:Actin Cytoskeleton / Q000502:physiology*; D051339:Actin Depolymerizing Factors; D017209:Apoptosis / Q000502:physiology; D053148:Caspase 3; D020169:Caspases / Q000502:physiology; D002462:Cell Membrane / Q000502:physiology; D002478:Cells, Cultured; D002843:Chromatin / Q000502:physiology*; D053938:DNA Fragmentation / Q000502:physiology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008840:Microfilament Proteins / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D054460:rho-Associated Kinases
D051339:Actin Depolymerizing Factors; D002843:Chromatin; D047908:Intracellular Signaling Peptides and Proteins; D008840:Microfilament Proteins; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases