title: Phosphorylation by MAPKAP kinase 2 activates Mg(2+)-ATPase activity of myosin II.
abstract: Mitogen-activated protein kinase activated protein (MAPKAP) kinase-2 was found to phosphorylate the regulatory light chain of myosin II (MRLC) in vitro in the absence of Ca2+/calmodulin. The tryptic peptides recovered from the MRLC phosphorylated by MAPKAP kinase-2 were identical to the phosphopeptides recovered from myosin light chain kinase (MLCK)-phosphorylated MRLC. Phosphoamino acid analysis revealed that MRLC was phosphorylated by these kinases at the serine residue. This phosphorylation by MAPKAP kinase-2 activated the actin-activated Mg(2+)-ATPase activity of myosin II. These findings indicated that MAPKAP kinase-2 may be a kinase that regulates the actin-activated Mg(2+)-ATPase activity of myosin II.
authors.affiliation: Department of Biological Science, Faculty of Science, Hiroshima University, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Komatsu
authors.forename: H
authors.initials: H
authors.lastname: Hosoya
mesh_terms: D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002645:Chickens; D004789:Enzyme Activation; D005895:Gizzard, Avian; D047908:Intracellular Signaling Peptides and Proteins; D020929:Mitogen-Activated Protein Kinase Kinases; D009130:Muscle, Smooth / Q000201:enzymology; D009218:Myosins / Q000378:metabolism*; D010446:Peptide Fragments / Q000302:isolation & purification; D010449:Peptide Mapping; D010748:Phosphopeptides / Q000302:isolation & purification; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D014357:Trypsin; D000099190:MAP-Kinase-Activated Kinase 2
chemical_list: D017301:Ca(2+) Mg(2+)-ATPase; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D047908:Intracellular Signaling Peptides and Proteins; D020929:Mitogen-Activated Protein Kinase Kinases; D009218:Myosins; D010446:Peptide Fragments; D010748:Phosphopeptides; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D014357:Trypsin; D000099190:MAP-Kinase-Activated Kinase 2