title: Identification of myosin II kinase from sea urchin eggs as protein kinase CK2.
abstract: Here we purified and identified a myosin II kinase from sea urchin eggs. The activity of this myosin II kinase in the egg extract was not significantly affected by Ca(2+)/calmodulin (CaM). Using sequential column chromatographies, we purified the myosin II kinase from the egg extract as a complex composed of 36- (p36) and 28-kDa (p28) proteins. Partial amino acid sequences of these two components were highly coincident with those of the alpha and beta subunits of protein kinase CK2 (formerly casein kinase II) in sea urchin eggs, respectively. To confirm that the purified myosin II kinase was CK2, we obtained a cDNA which encodes p36 from a cDNA library of sea urchin eggs. The amino acid sequence derived from the obtained cDNA showed over 70% homology to CK2 from various eukaryotes. Furthermore, recombinant p36, as well as the purified myosin II kinase, phosphorylated MRLC. One dimensional phosphopeptide mapping revealed that the phosphorylation site(s) of MRLC by both recombinant p36 and the purified myosin II kinase was identical. These clearly showed that the Ca(2+)/CaM-independent myosin II kinase activity in sea urchin eggs was identical to CK2.
authors.affiliation: Department of Biological Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, 739-8526, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Komaba
authors.forename: H
authors.initials: H
authors.lastname: Hamao
authors.forename: M
authors.initials: M
authors.lastname: Murata-Hori
authors.forename: H
authors.initials: H
authors.lastname: Hosoya
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D047390:Casein Kinase II; D002474:Cell-Free System / Q000201:enzymology; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D018994:Myosin Light Chains / Q000378:metabolism; D009218:Myosins / Q000378:metabolism; D010063:Ovum / Q000201:enzymology / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D012617:Sea Urchins / Q000201:enzymology / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D018076:DNA, Complementary; D018994:Myosin Light Chains; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases; D009218:Myosins