Regulation of myosin phosphatase by Rho and Rho-associated kinase (Rho-kinase)
The small guanosine triphosphatase Rho is implicated in myosin light chain (MLC) phosphorylation, which results in contraction of smooth muscle and interaction of actin and myosin in nonmuscle cells. The guanosine triphosphate (GTP)-bound, active form of RhoA (GTP.RhoA) specifically interacted with the myosin-binding subunit (MBS) of myosin phosphatase, which regulates the extent of phosphorylation of MLC. Rho-associated kinase (Rho-kinase), which is activated by GTP.RhoA, phosphorylated MBS and consequently inactivated myosin phosphatase. Overexpression of RhoA or activated RhoA in NIH 3T3 cells increased phosphorylation of MBS and MLC. Thus, Rho appears to inhibit myosin phosphatase through the action of Rho-kinase.
Kimura
K
K
Division of Signal Transduction, Nara Institute of Science and Technology, Ikoma 630-01, Japan.
Ito
M
M
Amano
M
M
Chihara
K
K
Fukata
Y
Y
Nakafuku
M
M
Yamamori
B
B
Feng
J
J
Nakano
T
T
Okawa
K
K
Iwamatsu
A
A
Kaibuchi
K
K
D016475:3T3 Cells; D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D007544:Isopropyl Thiogalactoside / Q000494:pharmacology; D008387:Marine Toxins; D051379:Mice; D008969:Molecular Sequence Data; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000502:physiology; D018994:Myosin Light Chains / Q000378:metabolism; D043263:Myosin-Light-Chain Phosphatase; D010080:Oxazoles / Q000494:pharmacology; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein
D000199:Actins; D047908:Intracellular Signaling Peptides and Proteins; D008387:Marine Toxins; D018994:Myosin Light Chains; D010080:Oxazoles; D007544:Isopropyl Thiogalactoside; C059041:calyculin A; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D010749:Phosphoprotein Phosphatases; D043263:Myosin-Light-Chain Phosphatase; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein