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Islet‐activating protein prevents nicotinic acid‐induced GTPase stimulation and GTP but not GTPγS‐induced adenylate cyclase inhibition in rat adipocytes
Author(s) -
Aktories Klaus,
Schultz Günter,
Jakobs Karl H.
Publication year - 1983
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(83)80254-3
Subject(s) - gtp' , adenylate kinase , gtpase , stimulation , cyclase , chemistry , gtp binding protein regulators , g protein , microbiology and biotechnology , endocrinology , medicine , biochemistry , biology , signal transduction , receptor , enzyme
The influence of islet‐activating protein (IAP), a Bordetella pertussis toxin, was studied on adenylate cyclase and GTPase activities in rat adipocyte membranes. Pretreatment of rats or intact rat adipocytes with IAP did not affect adenylate cyclase inhibition by the stable GTP analog, GTPγS, whereas inhibition by GTP was abolished. Concomitantly, activation of the adipocyte enzyme by sodium and its inhibition by nicotinic acid were prevented. Furthermore, IAP treatment of adipocyte membranes prevented nicotinic acid‐induced stimulation of a high affinity GTPase. The data suggest that a GTP‐hydrolyzing system involved in the inhibitory regulation of adenylate cyclase is the target of IAP's action.