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Myotonic dystrophy protein kinase phosphorylates the myosin phosphatase targeting subunit and inhibits myosin phosphatase activity
Author(s) -
Murányi Andrea,
Zhang Rongxin,
Liu Feizhou,
Hirano Katsuya,
Ito Masaaki,
Epstein Henry F.,
Hartshorne David J.
Publication year - 2001
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(01)02283-9
Subject(s) - phosphorylation , myotonic dystrophy , phosphatase , myosin , myosin light chain kinase , kinase , myosin light chain phosphatase , rho associated protein kinase , biology , protein subunit , protein kinase a , microbiology and biotechnology , dephosphorylation , biochemistry , genetics , gene
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.