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1,4‐Dihydropyridines modulate GTP hydrolysis by G o in neuronal membranes
Author(s) -
Sweeney M.I.,
Dolphin A.C.
Publication year - 1992
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(92)81148-f
Subject(s) - gtp' , gtpase , membrane , chemistry , receptor , hydrolysis , microbiology and biotechnology , g protein , biophysics , biochemistry , dihydropyridine , enzyme , calcium , biology , organic chemistry
Several lines of evidence suggest that L‐type Cu 2+ channels (1,4‐dihydropyridine receptors) are modulated by GTP‐binding, proteins. We have further examined this interaction by measuring the effect of 1,4‐dihydropyridines on GTPase activity in brain membranes. Dihydropyridine agonists significantly increased OTPase, reflected by an increase in the maximal rate of GTP hydrolysis, without affecting the affinity for GTP or the binding of a non‐hydrolysable analogue of GTP. The stimulating effect on GTPase was abolished by antisera raised against G o α but not G i α. L‐type Ca 2+ channels may act as endogenous GTPase activating proteins (GAPS) to stimulate GTP hydrolysis by G o .