Publications

• Purification and characterization of a calmodulin-dependent myosin heavy chain kinase from intestinal brush border.

  Rieker J.P., Swanljung-Collins H., Collins J.H.

  A calcium- and calmodulin-dependent kinase that represents the majority of the myosin heavy chain kinase activity in chicken intestinal brush borders has been highly purified. The purification steps include gel filtration, high performance chromatography on anion and cation exchangers, and affinit ... >> More

  A calcium- and calmodulin-dependent kinase that represents the majority of the myosin heavy chain kinase activity in chicken intestinal brush borders has been highly purified. The purification steps include gel filtration, high performance chromatography on anion and cation exchangers, and affinity chromatography on calmodulin-Sepharose. The purified kinase consists of a single major, apparently autophosphorylatable polypeptide of 50,000 daltons. The Stokes radius (68 A) and sedimentation coefficient (17.5 S) indicate that it has a molecular weight of approximately 490,000. The kinase catalyzed the incorporation of a maximum of 0.8 mol of phosphate/mol of heavy chain, and essentially no phosphate was incorporated into the light chains. This kinase is distinct from other myosin kinases, but has a number of properties in common with the type II calmodulin-dependent protein kinases. << Less

  J Biol Chem 262:15262-15268(1987) [PubMed] [EuropePMC]

• Membrane-bound Dictyostelium myosin heavy chain kinase: a developmentally regulated substrate-specific member of the protein kinase C family.

  Ravid S., Spudich J.A.

  A cDNA clone corresponding to the Dictyostelium myosin heavy chain kinase (MHCK) gene was isolated using antibodies specific to the purified enzyme. Sequence analysis of the cDNA revealed that the Dictyostelium MHCK possesses all of the domains characteristic of members of the protein kinase C fam ... >> More

  A cDNA clone corresponding to the Dictyostelium myosin heavy chain kinase (MHCK) gene was isolated using antibodies specific to the purified enzyme. Sequence analysis of the cDNA revealed that the Dictyostelium MHCK possesses all of the domains characteristic of members of the protein kinase C family. The amino-terminal region of the MHCK contains the cysteine-rich motif with an internal duplication that is present in all known protein kinase C species. This domain precedes sequences that are highly homologous to protein kinase catalytic domains. The carboxyl-terminal region contains a cluster of 23 serine and threonine residues that may represent the autophosphorylation domain of the Dictyostelium MHCK. These results, along with previous studies that indicate that this enzyme has very restrictive substrate specificity, incorporates approximately 20 mol of phosphate per mol of kinase through an autophosphorylation reaction, and is expressed only during development, suggest that the Dictyostelium MHCK is a distinct member of the protein kinase C family and imply that this kinase family, which may include members with very specific cellular functions, may be even more heterogeneous than previously thought. << Less

  Proc. Natl. Acad. Sci. U.S.A. 89:5877-5881(1992) [PubMed] [EuropePMC]

• Substrate specificity of Acanthamoeba myosin I heavy chain kinase as determined with synthetic peptides.

  Brzeska H., Lynch T.J., Martin B., Corigliano-Murphy A., Korn E.D.

  Phosphorylation of a single threonine (myosin IA) or serine (myosins IB and IC) in the heavy chains of the Acanthamoeba myosin I isozymes is required for expression of their actin-activated Mg2(+)-ATPase activities. We now report that the synthetic peptide Gly-Arg-Gly-Arg-Ser-Ser-Val-Tyr-Ser, whic ... >> More

  Phosphorylation of a single threonine (myosin IA) or serine (myosins IB and IC) in the heavy chains of the Acanthamoeba myosin I isozymes is required for expression of their actin-activated Mg2(+)-ATPase activities. We now report that the synthetic peptide Gly-Arg-Gly-Arg-Ser-Ser-Val-Tyr-Ser, which corresponds to the phosphorylated region of Acanthamoeba myosin IC, is a good substrate for myosin I heavy chain kinase: Km = 54 microM, and Vmax = 15 mumols/min.mg. The same serine is phosphorylated as in the native substrate (residue 6 in the above sequence), and kinase activity with the synthetic peptide as substrate is also stimulated by phosphatidylserine-enhanced autophosphorylation of the kinase. These results indicate that all of the essential sequence determinants of kinase specificity are contained within this 9-residue peptide. With the peptide as substrate, we found that another acidic phospholipid, phosphatidylinositol, also enhances autophosphorylation of the kinase whereas the neutral phospholipids phosphatidylcholine and phosphatidylethanolamine do not. By comparing the Km and Vmax values for a series of synthetic peptide substrates, we established that 1 basic amino acid is essential on the NH2-terminal side of the phosphorylation site, and two are preferable, and that a tyrosine is essential 2 residues away on the COOH-terminal side. There is a slight preference for arginines over lysines. All of these local sequence specificity determinants are present in the three native substrates, Acanthamoeba myosins IA, IB, and IC, and in two Dictyostelium myosin I isozymes that are putative substrates for the kinase. Similar sequences do not occur in the myosins I from intestinal brush border, which is not a substrate for the Acanthamoeba kinase. << Less

  J Biol Chem 265:16138-16144(1990) [PubMed] [EuropePMC]

• Myosin heavy chain kinase from developed Dictyostelium cells. Purification and characterization.

  Ravid S., Spudich J.A.

  We purified to homogeneity the Dictyostelium discoideum myosin heavy chain kinase that is implicated in the heavy chain phosphorylation increases that occur during chemotaxis. The kinase is initially found in the insoluble fraction of developed cells. The major purification step was achieved by af ... >> More

  We purified to homogeneity the Dictyostelium discoideum myosin heavy chain kinase that is implicated in the heavy chain phosphorylation increases that occur during chemotaxis. The kinase is initially found in the insoluble fraction of developed cells. The major purification step was achieved by affinity chromatography using a tail fragment of Dictyostelium myosin (LMM58) expressed in Escherichia coli (De Lozanne, A., Berlot, C. H., Leinwand, L. A., and Spudich, J. A. (1988) J. Cell Biol. 105, 2990-3005). The kinase has an apparent molecular weight of 84,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The apparent native molecular weight by gel filtration is 240,000. The kinase catalyzes phosphorylation of myosin heavy chain or LMM58 with similar kinetics, and the extent of phosphorylation for both is 4 mol of phosphate/mol. With both substrates the Vmax is about 18 mumol/min/mg and the Km is 15 microM. The myosin heavy chain kinase is specific to Dictyostelium myosin heavy chain, and the phosphorylated amino acid is threonine. The kinase undergoes autophosphorylation. Each mole of kinase subunit incorporates about 20 mol of phosphates. Phosphorylation of myosin by this kinase inhibits myosin thick filament formation, suggesting that the kinase plays a role in the regulation of myosin assembly. << Less

  J Biol Chem 264:15144-15150(1989) [PubMed] [EuropePMC]

• Purification and characterization of a myosin I heavy chain kinase from Acanthamoeba castellanii.

  Hammer J.A., Albanesi J.P., Korn E.D.

  In previous work from this laboratory, a partially purified protein kinase from the soil amoeba Acanthamoeba castellanii was shown to phosphorylate the heavy chain of the two single-headed Acanthamoeba myosin isoenzymes, myosin IA and IB, resulting in a 10-to 20-fold increase in their actin-activa ... >> More

  In previous work from this laboratory, a partially purified protein kinase from the soil amoeba Acanthamoeba castellanii was shown to phosphorylate the heavy chain of the two single-headed Acanthamoeba myosin isoenzymes, myosin IA and IB, resulting in a 10-to 20-fold increase in their actin-activated Mg2+-ATPase activities (Maruta, H., and Korn, E.D. (1977) J. Biol. Chem. 252, 8329-8332). A myosin I heavy chain kinase has now been purified to near homogeneity from Acanthamoeba by chromatography on DE-52 cellulose, phosphocellulose, and Procion red dye, followed by chromatography on histone-Sepharose. Myosin I heavy chain kinase contains a single polypeptide of 107,000 Da by electrophoretic analysis. Molecular sieve chromatography yields a Stokes radius of 4.1 nm, consistent with a molecular weight of 107,000 for a native protein with a frictional ratio of approximately 1.3:1. The kinase catalyzes the incorporation of 0.9 to 1.0 mol of phosphate into the heavy chain of both myosins IA and IB. Phosphoserine has been shown to be the phosphorylated amino acid in myosin IB. The kinase has highest specific activity toward myosin IA and IB, about 3-4 mumol of phosphate incorporated/min/mg (30 degrees C) at concentrations of myosin I that are well below saturating levels. The kinase also phosphorylates histone 2A, isolated smooth muscle light chains, and, to a very small extent, casein, but has no activity toward phosvitin or myosin II, a third Acanthamoeba myosin isoenzyme with a very different structure from myosin IA and IB. Myosin I heavy chain kinase requires Mg2+ but is not dependent on Ca2+, Ca2+/calmodulin, or cAMP for activity. The kinase undergoes an apparent autophosphorylation. << Less

  J Biol Chem 258:10168-10175(1983) [PubMed] [EuropePMC]

• Purification and characterization of a myosin heavy chain kinase from Dictyostelium discoideum.

  Cote G.P., Bukiejko U.

  A Dictyostelium discoideum myosin heavy chain kinase has been purified 14,000-fold to near homogeneity. The enzyme has a Mr = 130,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and greater than 700,000 as determined by gel filtration on Bio-Gel A-1.5m. The enzyme ha ... >> More

  A Dictyostelium discoideum myosin heavy chain kinase has been purified 14,000-fold to near homogeneity. The enzyme has a Mr = 130,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and greater than 700,000 as determined by gel filtration on Bio-Gel A-1.5m. The enzyme has a specific activity of 1 mumol/min X mg when assayed at a Dictyostelium myosin concentration of 0.3 mg/ml. A maximum of 2 mol of phosphate/mol of myosin is incorporated by the kinase, and the phosphorylated amino acid is threonine. Phosphate is incorporated only into the myosin heavy chains, not into the light chains. The actin-activated Mg2+-ATPase of Dictyostelium myosin is inhibited 70-80% following maximal phosphorylation with the kinase. The myosin heavy chain kinase requires 1-2 mM Mg2+ for activity and is most active at pH 7.0-7.5. The activity of the enzyme is not significantly altered by the presence of Ca2+, Ca2+ and calmodulin, EGTA, cAMP, or cGMP. When incubated with Mg2+ and ATP, phosphate is incorporated into the myosin heavy chain kinase, perhaps by autophosphorylation. << Less

  J Biol Chem 262:1065-1072(1987) [PubMed] [EuropePMC]