title: Myosin phosphatase target subunit: Many roles in cell function.
abstract: Phosphorylation of myosin II is important in many aspects of cell function and involves a myosin kinase, e.g. myosin light chain kinase, and a myosin phosphatase (MP). MP is regulated by the myosin phosphatase target subunit (MYPT1). The domain structure, properties, and genetic analyses of MYPT1 and its isoforms are outlined. MYPT1 binds the catalytic subunit of type 1 phosphatase, delta isoform, and also acts as an interactive platform for many other proteins. A key reaction for MP is with phosphorylated myosin II and the first process shown to be regulated by MP was contractile activity of smooth muscle. In cell division and cell migration myosin II phosphorylation also plays a critical role and these are discussed. However, based on the wide range of partners for MYPT1 it is likely that MP is implicated with substrates other than myosin II. Open questions are whether the diverse functions of MP reflect different cellular locations and/or specific roles for the MYPT1 isoforms.
authors.affiliation: Department of Molecular Biology and Biochemistry, Rutgers University, 604, Allison Road, Piscataway, NJ 08855, USA.
authors.forename: Fumio
authors.initials: F
authors.lastname: Matsumura
authors.forename: David J
authors.initials: DJ
authors.lastname: Hartshorne
mesh_terms: D002455:Cell Division / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D004789:Enzyme Activation; D008954:Models, Biological; D024462:Myosin Type II / Q000378:metabolism*; D043263:Myosin-Light-Chain Phosphatase / Q000378:metabolism*; D010766:Phosphorylation
chemical_list: D043263:Myosin-Light-Chain Phosphatase; C490372:PPP1R12A protein, human; D024462:Myosin Type II