Abstract
The small GTPase Rho and one of its targets, Rho-kinase (also termed ROK or ROCK), are implicated in various cellular functions including stress fiber formation, smooth muscle contraction, tumor cell invasion and cell motility. We have previously reported that Rho-kinase accumulates at the cleavage furrow during cytokinesis in several cultured cells. Here, using Rho-kinase inhibitors, Y-27632 and HA1077, we found that Rho-kinase is responsible for the phosphorylation of myosin regulatory light chain at Ser19 in the cleavage furrow during cytokinesis. On the other hand, phosphorylation of ezrin/radixin/moesin (ERM) proteins at the cleavage furrow was enhanced by the addition of the above Rho-kinase inhibitors. Treatment with Y-27632 strongly enhanced the accumulation of Rho-kinase but not RhoA and citron kinase at the cleavage furrow. Furthermore, the furrow ingression in cytokinesis was significantly prolonged in the presence of Y-27632. These results suggest that Rho-kinase is involved in the progression of cytokinesis through the phosphorylation of several proteins including myosin light chain at the cleavage furrow.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / analogs & derivatives*
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1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / pharmacology
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Actins / metabolism
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Amides / pharmacology
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Blood Proteins / metabolism*
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Carrier Proteins / metabolism
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Cell Division* / drug effects
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Cell Line
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Cytoskeletal Proteins / metabolism*
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Fluorescent Antibody Technique
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HeLa Cells
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Humans
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Intracellular Signaling Peptides and Proteins
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Membrane Proteins / metabolism*
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Microfilament Proteins / metabolism*
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Myosin Light Chains / metabolism*
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Phosphoproteins / metabolism*
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Phosphorylation / drug effects
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Protein Serine-Threonine Kinases / antagonists & inhibitors
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Protein Serine-Threonine Kinases / metabolism*
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Pyridines / pharmacology
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Stress Fibers / chemistry
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Stress Fibers / drug effects
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Stress Fibers / metabolism
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rho-Associated Kinases
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rhoA GTP-Binding Protein / metabolism
Substances
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Actins
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Amides
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Blood Proteins
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Carrier Proteins
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Cytoskeletal Proteins
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Intracellular Signaling Peptides and Proteins
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Membrane Proteins
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Microfilament Proteins
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Myosin Light Chains
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Phosphoproteins
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Pyridines
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ezrin
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Y 27632
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moesin
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radixin
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1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine
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citron-kinase
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Protein Serine-Threonine Kinases
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rho-Associated Kinases
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rhoA GTP-Binding Protein
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fasudil