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Regulation by protein kinase‐C of putative P‐type Ca channels expressed in Xenopus oocytes from cerebellar mRNA
Author(s) -
Fournier Franck,
Charnet Pierre,
Bourinet Emmanuel,
Vilbert Carole,
Matifat Fabrice,
Charpentier Gilles,
Navarre Pierre,
Brûlé Gérard,
Marlot Daniel
Publication year - 1993
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(93)81504-s
Subject(s) - protein kinase c , xenopus , biology , staurosporine , microbiology and biotechnology , long term potentiation , diacylglycerol kinase , phosphorylation , receptor , biochemistry , gene
Xenopus oocytes injected with rat cerebellar mRNA expressed functional voltage‐dependent Ca channels detected as an inward Ba current ( I Ba ). The pharmacological resistance to dihydropyridines and ω‐conotoxin together with the blockade obtained with Agelenopsis aperta venom suggest that these channels could be somehow assimilated to P‐type Ca channels. The precise nature of the transplanted Ca channels was assessed by hybrid‐arrest experiments using a specific oligonucleotide antisense‐derivated from the recently cloned α1‐subunit of P channels (BI‐1 clone). In addition, we demonstrate that exogenous Ca channel activity was enhanced by two different PKC activators (a phorbol ester and a structural analog to diacylglycerol). The general electrophysiological and pharmacological properties of the stimulated Ca channels remain unchanged. This potentiation induced by PKC activators is antagonized by a PKC inhibitor (staurosporine) and by a monoclonal antibody directed against PKC. It is concluded that P‐type Ca channels are potentially regulated by PKC phosphorylation and the functional relevance of this intracellular pathway is discussed.