Phosphorylation of the regulatory subunit of smooth muscle protein phosphatase 1M at Thr850 induces its dissociation from myosin.
Rho kinase is known to control smooth muscle contractility by phosphorylating the 110 kDa myosin-targetting subunit (MYPT1) of the myosin-associated form of protein phosphatase 1 (PP1M). Phosphorylation of MYPT1 at Thr695 has previously been reported to inhibit the catalytic activity of PP1. Here, we show that the phosphorylation of Thr850 by Rho kinase dissociates PP1M from myosin, providing a second mechanism by which myosin phosphatase activity is inhibited.
Velasco
Guillermo
G
Division of Signal Transduction Therapy, School of Life Sciences, University of Dundee, DD1 5EH, Dundee, UK.
Armstrong
Chris
C
Morrice
Nick
N
Frame
Sheelagh
S
Cohen
Philip
P
D000818:Animals; D001483:Base Sequence; D020134:Catalytic Domain; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D009130:Muscle, Smooth / Q000378:metabolism*; D043263:Myosin-Light-Chain Phosphatase; D009218:Myosins / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D054645:Protein Phosphatase 1; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D021122:Protein Subunits; D013912:Threonine / Q000378:metabolism; D054460:rho-Associated Kinases
D047908:Intracellular Signaling Peptides and Proteins; D021122:Protein Subunits; D013912:Threonine; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; D043263:Myosin-Light-Chain Phosphatase; D009218:Myosins