Characterization of a Ca2+/calmodulin-dependent protein kinase cascade. Molecular cloning and expression of calcium/calmodulin-dependent protein kinase kinase

J Biol Chem. 1995 Aug 18;270(33):19320-4. doi: 10.1074/jbc.270.33.19320.

Abstract

Recent studies have demonstrated that Ca2+/calmodulin-dependent protein kinase IV (CaM-kinase IV) can mediate Ca(2+)-dependent regulation of gene expression through the phosphorylation of transcriptional activating proteins. We have previously identified and purified a 68-kDa rat brain CaM-kinase kinase that phosphorylates and increases total and Ca(2+)-independent activities of CaM-kinase IV (Tokumitsu, H., Brickey, D. A., Gold, J., Hidaka, H., Sikela, J., and Soderling, T. R. (1994) J. Biol. Chem. 269, 28640-28647). Using a partial amino acid sequence of the purified brain kinase, a CaM-kinase kinase cDNA was cloned from a rat brain cDNA library. Northern blot analysis showed that CaM-kinase kinase mRNA (3.4 kilobases) was expressed in rat brain, thymus, and spleen. Sequence analyses revealed that the cDNA encoded a 505-amino acid protein, which contained consensus protein kinase motifs and was 30-40% homologous with members of the CaM-kinase family. Expression of the cDNA in COS-7 cells yielded an apparent 68-kDa CaM-binding protein, which catalyzed in vitro activation in the presence of Mg2+/ATP and Ca2+/ CaM of CaM-kinases I and IV but not of CaM-kinase II. Co-expression of CaM-kinase kinase with CaM-kinase IV gave a 14-fold enhancement of cAMP-response element-binding protein-dependent gene expression compared with CaM-kinase IV alone. These results are consistent with the hypothesis that CaM-kinases I and IV are regulated through a unique signal transduction cascade involving CaM-kinase kinase.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Brain / enzymology
  • Calcium-Calmodulin-Dependent Protein Kinase Kinase
  • Calcium-Calmodulin-Dependent Protein Kinases / genetics
  • Calcium-Calmodulin-Dependent Protein Kinases / metabolism*
  • Cell Line
  • Cloning, Molecular
  • DNA, Complementary
  • Enzyme Activation
  • Gene Expression Regulation, Enzymologic
  • Molecular Sequence Data
  • Protein Serine-Threonine Kinases*
  • Rats
  • Sequence Homology, Amino Acid
  • Spodoptera
  • Substrate Specificity

Substances

  • DNA, Complementary
  • Protein Serine-Threonine Kinases
  • Calcium-Calmodulin-Dependent Protein Kinase Kinase
  • Calcium-Calmodulin-Dependent Protein Kinases

Associated data

  • GENBANK/L42810