Sequences of autophosphorylation sites in neuronal type II CaM kinase that control Ca2(+)-independent activity

Neuron. 1988 Sep;1(7):593-604. doi: 10.1016/0896-6273(88)90109-2.


After initial activation by Ca2+, the catalytic activity of type II Ca2+/calmodulin-dependent protein kinase rapidly becomes partially independent of Ca2+. The transition is caused by autophosphorylation of a few subunits in the dodecameric holoenzyme, which is composed of varying proportions of two homologous types of subunits, alpha (50 kd) and beta (58-60 kd). We have identified one site in the alpha subunit (Thr286) and two in the beta subunit (Thr287 and Thr382) that are rapidly autophosphorylated. We show that phosphorylation of alpha-Thr286 and beta-Thr287, which are located immediately adjacent to the calmodulin binding domain, controls Ca2(+)-independent activity. In contrast, phosphorylation of beta-Thr382 is not required to maintain Ca2+ independence. It is absent in the alpha subunit and is selectively removed from the minor beta' subunit, apparently by alternative splicing. Regulation of the presence of beta-Thr382 in the holoenzyme by both differential gene expression and alternative splicing suggests that it may have an important but highly specialized function.

Publication types

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

MeSH terms

  • Animals
  • Brain / enzymology*
  • Brain Chemistry
  • Calcium / physiology*
  • Calcium-Calmodulin-Dependent Protein Kinases
  • Cattle
  • In Vitro Techniques
  • Phosphorylation
  • Protein Kinases / metabolism*


  • Protein Kinases
  • Calcium-Calmodulin-Dependent Protein Kinases
  • Calcium