IUBMB Enzyme Nomenclature


Accepted name: myosin-light-chain kinase

Reaction: ATP + [myosin light chain] = ADP + [myosin light chain] phosphate

Other name(s): [myosin-light-chain] kinase; ATP:myosin-light-chain O-phosphotransferase; calcium/calmodulin-dependent myosin light chain kinase; MLCK; MLCKase; myosin kinase; myosin light chain kinase; myosin light chain protein kinase; myosin light-chain kinase (phosphorylating); smooth-muscle-myosin-light-chain kinase; STK18

Systematic name: ATP:[myosin light chain] O-phosphotransferase

Comments: Requires Ca2+ and calmodulin for activity. The 20-kDa light chain from smooth muscle myosin is phosphorylated more rapidly than any other acceptor, but light chains from other myosins and myosin itself can act as acceptors, but more slowly.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 51845-53-5


1. Adelstein, R.S. and Klee, C.B. Purification and characterization of smooth muscle myosin light chain kinase. J. Biol. Chem. 256 (1981) 7501-7509. [PMID: 6894756]

2. Hathaway, D.R. and Adelstein, R.S. Human platelet myosin light chain kinase requires the calcium-binding protein calmodulin for activity. Proc. Natl. Acad. Sci. USA 76 (1979) 1653-1657. [PMID: 156362]

3. Pires, E., Perry, S.V. and Thomas, M.A.W. Myosin light-chain kinase, a new enzyme from striated muscle. FEBS Lett. 41 (1974) 292-296. [PMID: 4853304]

4. Nunnally, M.H., Rybicki, S.B. and Stull, J.T. Characterization of chicken skeletal muscle myosin light chain kinase. Evidence for muscle-specific isozymes. J. Biol. Chem. 260 (1985) 1020-1026. [PMID: 3881420]

5. Edelman, A.M., Takio, K., Blumenthal, D.K., Hansen, R.S., Walsh, K.A., Titani, K. and Krebs, E.G. Characterization of the calmodulin-binding and catalytic domains in skeletal muscle myosin light chain kinase. J. Biol. Chem. 260 (1985) 11275-11285. [PMID: 3897230]

6. Mal, T.K., Skrynnikov, N.R., Yap, K.L., Kay, L.E. and Ikura, M. Detecting protein kinase recognition modes of calmodulin by residual dipolar couplings in solution NMR. Biochemistry 41 (2002) 12899-12906. [PMID: 12390014]

7. Sobieszek, A. Enzyme kinetic characterization of the smooth muscle myosin phosphorylating system: activation by calcium and calmodulin and possible inhibitory mechanisms of antagonists. Biochim. Biophys. Acta 1450 (1999) 77-91. [PMID: 10231558]

8. Sobieszek, A., Borkowski, J. and Babiychuk, V.S. Purification and characterization of a smooth muscle myosin light chain kinase-phosphatase complex. J. Biol. Chem. 272 (1997) 7034-7041. [PMID: 9054394]

9. Fujita, K., Ye, L.H., Sato, M., Okagaki, T., Nagamachi, Y. and Kohama, K. Myosin light chain kinase from skeletal muscle regulates an ATP-dependent interaction between actin and myosin by binding to actin. Mol. Cell. Biochem. 190 (1999) 85-90. [PMID: 10098974]

[EC created 1986 as EC, transferred 2005 to EC]

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