title: Phosphorylation of vertebrate smooth muscle and nonmuscle myosin heavy chains in vitro and in intact cells.
abstract: In this article we summarize our recent experiments studying the phosphorylation of vertebrate myosin heavy chains by protein kinase C and casein kinase II. Protein kinase C phosphorylates vertebrate non-muscle myosin heavy chains both in vitro and in intact cells. A single serine residue near the end of the helical portion of the myosin rod is the only site phosphorylated in a variety of vertebrate nonmuscle myosin heavy chains. There does not appear to be a site for protein kinase C phosphorylation in vertebrate smooth muscle myosin heavy chains. Casein kinase II phosphorylates a single serine residue located near the carboxyl terminus of the 204 x 10(3) Mr smooth muscle myosin heavy chain in vitro as well as in cultured smooth muscle cells. It does not phosphorylate the 200 x 10(3) Mr smooth muscle myosin heavy chain. However, the site is present in vertebrate nonmuscle myosin heavy chains. The 204 x 10(3) Mr myosin heavy chain of embryonic chicken gizzard smooth muscle is exceptional in not containing a site for casein kinase II phosphorylation.
authors.affiliation: Laboratory of Molecular Cardiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892.
authors.forename: C A
authors.initials: CA
authors.lastname: Kelley
authors.forename: S
authors.initials: S
authors.lastname: Kawamoto
authors.forename: M A
authors.initials: MA
authors.lastname: Conti
authors.forename: R S
authors.initials: RS
authors.lastname: Adelstein
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D047388:Casein Kinases; D006801:Humans; D008969:Molecular Sequence Data; D009130:Muscle, Smooth / Q000378:metabolism*; D009218:Myosins / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism; D014714:Vertebrates
chemical_list: D011494:Protein Kinases; D047388:Casein Kinases; D011493:Protein Kinase C; D009218:Myosins