Autophosphorylation of type II Ca2+/calmodulin-dependent protein kinase in cultures of postnatal rat hippocampal slices - PubMed (original) (raw)

Autophosphorylation of type II Ca2+/calmodulin-dependent protein kinase in cultures of postnatal rat hippocampal slices

S S Molloy et al. Proc Natl Acad Sci U S A. 1991.

Abstract

Autophosphorylation of Thr286 on type II Ca2+/calmodulin-dependent protein kinase (CaM kinase) in vitro causes kinase activity to become partially independent of Ca2+. Here we report that Thr286 is the major CaM kinase autophosphorylation site occupied in situ in "organotypic" hippocampal cultures. Measurement of Ca(2+)-independent CaM kinase activity revealed that approximately one-third of the kinase is autophosphorylated in situ when the basal Ca2+ concentration is 15-43 nM. This proportion was substantially reduced 30 min after removal of extracellular Ca2+ or treatment of the cultures with protein kinase inhibitors and was increased by treatment with okadaic acid. Therefore, the high proportion of autophosphorylated kinase at basal Ca2+ concentrations appears to be maintained by Ca(2+)-dependent autophosphorylation. Homogenates of intact hippocampi also contain a high proportion of Ca(2+)-independent type II CaM kinase, 13-23% depending on developmental age. Thus, in hippocampal neurons, an important function of the autophosphorylation mechanism may be to produce a relatively high level of CaM kinase activity, even at basal Ca2+ concentrations, permitting both upward and downward local regulation by physiological agents.

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References

    1. Neuron. 1988 Sep;1(7):593-604 - PubMed
    1. Nature. 1970 Aug 15;227(5259):680-5 - PubMed
    1. J Biol Chem. 1989 Dec 25;264(36):21830-6 - PubMed
    1. Science. 1989 Aug 25;245(4920):862-6 - PubMed
    1. Nature. 1989 Aug 17;340(6234):554-7 - PubMed

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