, Volume 40, Issue 11, pp 1185–1188 | Cite as

Structure and function of a calmodulin-dependent smooth muscle myosin light chain kinase

  • G. Bailin


In smooth muscle the Mr 20,000 light chain of myosin is phosphorylated by a calmodulin-dependent protein kinase. It consists of 2 subunits: calmodulin, an acidic protein of Mr 17,000 that binds 4 moles of Ca2+; and a larger protein of Mr circa 130,000. Activation of the kinase is dependent upon their association in the presence of Ca2+. Cyclic AMP-dependent protein kinase phosphorylation of the myosin light chain kinase occurs at 2 sites. It decreases the affinity of the kinase for calmodulin and a reduction in the rate of light chain phosphorylation occurs. The kinase has an overall asymmetric shape composed of a globular head and tail region for the skeletal muscle enzyme. Trypsin digestion of this kinase releases a fragment of Mr 36,000 from the globular region that contains the catalytic and calmodulin binding sites. Chymotrypsin digestion of the kinase from smooth muscle generates a fragment of Mr 80,000 that does not contain the calmodulin binding or cyclic AMP-dependent protein kinase phosphorylation sites. It is a Ca2+-independent form of the kinase that phosphorylates the light chain of myosin. These structural features indicate a regulatory role for the kinase in smooth muscle phosphorylation and contraction.

Key words

Calmodulin cyclic AMP myosin protein kinase phosphorylation smooth muscle (gizzards) 


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  1. 1.
    Adachi, K., Carruthers, C. A., and Walsh, M. P., Identification of the native form of chicken gizzard myosin light chain kinase with the aid of monoclonal antibodies. Biochem. biophys. Res. Commun.115 (1983) 855–863.CrossRefPubMedGoogle Scholar
  2. 2.
    Adelstein, R. S., and Eisenberg, E., Regulation and kinetics of the actin-myosin ATP interaction. A. Rev. Biochem.49 (1980) 921–956.CrossRefGoogle Scholar
  3. 3.
    Adelstein, R. S., and Klee, C. B., Purification and characterization of smooth muscle myosin light chain kinase. J. biol. Chem.256 (1981) 7501–7510.PubMedGoogle Scholar
  4. 4.
    Aksoy, M. O., Murphy, R. A., and Kamm, K. E., Role of calcium and myosin light chain phosphorylation in the regulation of smooth muscle. Am. J. Physiol.242 (1982) C109-C116.PubMedGoogle Scholar
  5. 5.
    Bailin, G., Peptide fragments of the heavy chain region of phosphorylated and dinitrophenylated gizzard myosin. Biochim. biophys. Acta747 (1983) 171–176.PubMedGoogle Scholar
  6. 6.
    Cambell, K. P., and MacLennan, D. H., A calmodulin-dependent protein kinasase system from skeletal muscle sarcoplasmic reticulum. J. biol. Chem.257 (1982) 1238–1241.PubMedGoogle Scholar
  7. 7.
    Cheung, W. Y., Calmodulin plays a pivotal role in cellular regulation. Science207 (1980) 19–27.PubMedGoogle Scholar
  8. 8.
    Chiesi, M., and Carafoli, E., Role of calmodulin in skeletal muscle sarcoplasmic reticulum. Biochemistry22 (1983) 985–993.CrossRefPubMedGoogle Scholar
  9. 9.
    Conti, M. A., and Adelstein, R. S., The relationship between calmodulin binding and phosphorylation of smooth muscle myosin kinase by the catalytic subunit of cAMP-dependent protein kinase. J. biol. Chem.256 (1981) 3178–3181.PubMedGoogle Scholar
  10. 10.
    Crouch, T. H., Horoyde, M. J., Collins, J. H., Solaro, R. J., and Potter, J. D., Interaction of calmodulin with skelated muscle myosin light chain kinase. Biochemistry20 (1981) 6318–6325.PubMedGoogle Scholar
  11. 11.
    Dabrowska, R., Sherry, J. M. F., Aromatorio, D. K., and Hartshorne, D. J., Modulator protein as a component of the myosin light chain kinase from chicken gizzards. Biochemistry17 (1978) 253–258.CrossRefPubMedGoogle Scholar
  12. 12.
    Edelman, A. M., and Krebs, E. G., Phosphorylation of skeletal muscle myosin light chain kinase by the catalytic subunit of cAMP-dependent protein kinase. FEBS Lett.138 (1982) 292–298.CrossRefGoogle Scholar
  13. 13.
    Hartshorne, D., Phosphorylation of myosin and the regulation of smooth muscle actomyosin, in: Cell and Muscle Molity, vol. 2, pp. 185–220. Eds R. M. Dowben and J. W. Shay, Plenum Press, New York 1982.Google Scholar
  14. 14.
    Hidaka, H., Naka, M., and Yamaki, T., Effect of novel specific myosin light chain kinase inhibitors on Ca2+-activated Mg2+-ATPase of chicken gizzard actomyosin. Biochem. biophys. Res. Commun.90 (1979) 695–699.CrossRefGoogle Scholar
  15. 15.
    Ikebe, M., Hinkins, S., and Hartshorne, D. J., Correlation of enzymatic properties and conformation of smooth muscle myosin. Biochemistry22 (1983) 4580–4587.CrossRefPubMedGoogle Scholar
  16. 16.
    Kemp, B. E., Pearson, R. B., and House, C., Role of basic amino acid residues in the phosphorylation of synthetic peptides by myosin light chain kinase. Proc. natl Acad. Sci. USA80 (1983) 7471–7475.PubMedGoogle Scholar
  17. 17.
    Kendrick-Jones, J., Cande, W. Z., Tooth, P. J., Smith, R. C., and Scholey, J. M., Studies on the effect of phosphorylation of the 20,000 M, light chain of vertebrate smooth muscle myosin. J. molec. Biol.165 (1983) 139–162.PubMedGoogle Scholar
  18. 18.
    Kerrick, W. G. L., Hoar, P. E., and Cassidy, P. S., Calcium-activated tension: the role of myosin light chain phosphorylation. Fedn. Proc.165 (1983) 1558–1563.Google Scholar
  19. 19.
    Manning, D. R., and Stull, J. T., Myosin light chain phosphorylatin and phosphorylase ‘a’ activity in rat extensor digtiorum longus muscle. Biochem. biophys. Res. Commun.90 (1979) 164–170.CrossRefPubMedGoogle Scholar
  20. 20.
    Mayr, G. W., and Heilmeyer, L. M. G. Jr. Shape and substructure of skeletal muscle myosin light chain kinase. Biochemistry22 (1983) 4316–4326.CrossRefPubMedGoogle Scholar
  21. 21.
    Miller, J. R., Silver, P. J., and Stull, J. T., Role of MLCK phosphorylation in beta-adrenergic relaxation of tracheal smooth muscle. Molec. Pharmac.24 (1983) 235–242.Google Scholar
  22. 22.
    Mrwa, U., and Hartshorne, D. J., Phosphorylation of smooth muscle myosin and myosin light chains. Fedn Proc.39 (1980) 1544–1573.Google Scholar
  23. 23.
    Nairn, A. C., and Perry, S. V., Calmodulin and myosin light chain kinase of rabbit fast skeletal muscle. Biochem. J.179 (1979) 89–97.PubMedGoogle Scholar
  24. 24.
    Nunnally, M. H., and Stull, J. T., Mammalian skeletal muscle myosin light chain kinases. A comparisonof antiserum cross reactivity. J. biol. Chem.259 (1984) 1776–1780.PubMedGoogle Scholar
  25. 25.
    Pato, M. D., and Adelstein, R. S., Purification and characterization of a multisubunit phosphatase from turkey gizzard smooth muscle. J. biol. Chem.258 (1983) 7047–7054.PubMedGoogle Scholar
  26. 26.
    Pemrick, S. M., The phosphorylated L2 light chain of skeletal myosin is a modifier of the actomyosin ATPase. J. biol. Chem.255 (1980) 8836–8841.PubMedGoogle Scholar
  27. 27.
    Potter, J. D., Seidel, J. C., Leavis, P. C., Lehrer, S. S., and Gergely, J., in: Calcium binding protein, pp. 179–196. Eds. W. Drabikowski, H. Strzelecka-Golaszewska and E. Carafoli. Elsevier, Amsterdam 1974.Google Scholar
  28. 28.
    Silver, P. J., and Stull, J. T., Effects of calmodulin antagonist fluphenazine on phosphorylation of myosin and phosphorylase in intact smooth muscle. Molec. Pharmac.23 (1983) 665–670.Google Scholar
  29. 29.
    Sobieszek, A., Vertebrate smooth muslce myosin, enzymatic and structural properties, in: Biochemistry of Smooth Muscle, pp. 413–443. Ed. N. L. Stephens. University Park Press, Baltimore 1977.Google Scholar
  30. 30.
    Srivastava, S., and Hartshorne, D. J., Conversion of a Ca2+-dependent myosin light chain kinase from skeletal muscle to a Ca2+-independent form. Biochem. biophys. Res. Commun.110 (1983) 701–708.CrossRefPubMedGoogle Scholar
  31. 31.
    Stull, J. T., Blumenthal, D. K., and Cooke, R., Regulation of contraction by myosin phosphorylation. Biochem. Pharmac.29 (1980) 2537–2543.CrossRefGoogle Scholar
  32. 32.
    Stull, J. T., Manning, D. R., High, W. C., and Blumenthal, D. K., Phosphorylation of contractile proteins in heart and skeletal muscle. Fedn Proc.39 (1980) 1552–1557.Google Scholar
  33. 33.
    Tanaka, T., Ohmura, T., Yamakado, T., and Hedaka, H., Two types of calcium dependent protein phosphorylations modulated by calmodulin antagonists. Naphthalene derivatives. Molec. Pharmac.22 (1982) 408–412.Google Scholar
  34. 34.
    Walsh, M. P., Bridenbaugh, R., Kerrick, W. G. L., and Hartshorne, D. J., Gizzard Ca2+-independent myosin light chain kinase: evidence in facvor of the phosphorylation theory. Fedn Proc.42 (1983) 45–49.Google Scholar
  35. 35.
    Walsh, M. P., Dabrowska, R., Hinkins, S., and Hartshorne, D. J., Calcium independent myosin light chain kinase of smooth muscle. Preparation by limited chymotryptic digestion of the calcium ion dependent enzyme, purification and characterization. Biochemistry21 (1982) 1919–1925.CrossRefPubMedGoogle Scholar
  36. 36.
    Walsh, M. P., Hinkins, S., Flink, I. L., and Hartshorne, D. J., Bovine stomach myosin light chain kinase. Purification, characterization and comparison with the turkey gizzard enzyme. Biochemistry21 (1982) 6890–6896.CrossRefPubMedGoogle Scholar
  37. 37.
    Walsh, M. P., Hinkins, S., Muguruma, M., and Hartshorne, D. J., Identification of two forms of myosin light chain kinase in turkey gizzard. FEBS Lett.153 (1983) 156–160.CrossRefPubMedGoogle Scholar
  38. 38.
    Yagi, K., Yazawa, M., Kakiuchi, S., Ohshima, M., and Uenishi, K., Identification of an activator protein for myosin light chain kinase as the Ca2+-dependent modulatory protein. J. biol. chem.253 (1978) 1338–1340.PubMedGoogle Scholar

Copyright information

© Birkhäuser Verlag 1984

Authors and Affiliations

  • G. Bailin
    • 1
  1. 1.Department of BiochemistryUMDNJ-School of Osteopathic MedicinePiscatawayUSA

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