Myotonic dystrophy protein kinase phosphorylates the myosin phosphatase targeting subunit and inhibits myosin phosphatase activity

FEBS Letters

Liu, Feizhou⁵  Zhang, Rongxin⁴  Hartshorne, David J.⁶  Ito, Masaaki²  Epstein, Henry F.¹  Hirano, Katsuya³  Murányi, Andrea⁶ 

[1] Departments of Neurology, Molecular Physiology and Biophysics and Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030-3498, USA;1st Department of Internal Medicine, Mie University School of Medicine, Tsu, Mie 514, Japan;Division of Molecular Cardiology, Faculty of Medicine, Kyushu University, Fukuoka 812-8582, Japan;Department of Neurology, Baylor College of Medicine, Houston, TX 77030-3498, USA;Departments of Neurology and Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030-3498, USA;Muscle Biology Group, Shantz Building, University of Arizona, Tucson, AZ 85721-0038, USA

关键词: Myosin target subunit;    Myosin phosphatase;    Myotonic dystrophy protein kinase;    Rho-kinase;    DMPK;    myotonic dystrophy protein kinase;    MDFPK;    myotonic dystrophy family of protein kinases;    MP;    myosin phosphatase;    MYPT;    myosin phosphatase target subunit;    PP1cδ;    delta isoform of the catalytic subunit of protein phosphatase type 1;    Rho-kinase;    Rho-associated protein kinase (ROK;    ROCK;    p160ROCK);    GST;    glutathione S-transferase;   

DOI  :  10.1016/S0014-5793(01)02283-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Myotonic dystrophy protein kinase (DMPK) and Rho-kinase are related. An important function of Rho-kinase is to phosphorylate the myosin-binding subunit of myosin phosphatase (MYPT1) and inhibit phosphatase activity. Experiments were carried out to determine if DMPK could function similarly. MYPT1 was phosphorylated by DMPK. The phosphorylation site(s) was in the C-terminal part of the molecule. DMPK was not inhibited by the Rho-kinase inhibitors, Y-27632 and HA-1077. Several approaches were taken to determine that a major site of phosphorylation was T654. Phosphorylation at T654 inhibited phosphatase activity. Thus both DMPK and Rho-kinase may regulate myosin II phosphorylation.

【 授权许可】

Unknown