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Presence of three pertussis toxin substrates and G o α immunoreactivity in both plasma and granule membranes of chromaffin cells
Author(s) -
Toutant Madeleine,
Aunis Dominique,
Bockaert Joël,
Homburger Vincent,
Rouot Bruno
Publication year - 1987
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(87)80174-6
Subject(s) - pertussis toxin , granule (geology) , adp ribosylation , toxin , adrenal medulla , bordetella pertussis , membrane , g protein , extracellular , gtp' , biochemistry , biology , chemistry , microbiology and biotechnology , enzyme , receptor , endocrinology , catecholamine , paleontology , nad+ kinase , genetics , bacteria
GTP‐binding proteins have been proposed to be involved in some secretory processes. Bordetella pertussis toxin is known to catalyze ADP‐ribosylation of several GTP‐binding proteins. In this paper, the subcellular localization of B. pertussis toxin substrates has been explored in chromaffin cells of bovine adrenal medulla. With appropriate gel electrophoresis conditions, three ADP‐ribosylated substrates of 39, 40 and 41 kDa were detectable in both plasma and granule membranes. The more intense labelling occurred on the 40 kDa component, while the 41 kDa species exhibited electrophoretic mobility similar to that of G i α. Significant immunoreactivity with anti‐G o α antibodies was detected at the level of the 39 kDa faster component. The association of G‐proteins with granule and plasma membranes suggests the involvement of these proteins in the exocytotic process or in its regulation.