TRANSLATIONAL PHYSIOLOGY Distinct role of Rab3A and Rab3B in secretory activity of rat melanotrophs
نویسندگان
چکیده
M. Rupnik, M. Kreft, F. Nothias, S. Grilc, L. K. Bobanovic, L. Johannes, T. Kiauta, P. Vernier, F. Darchen, and R. Zorec Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, School of Medicine, and Celica Biomedical Sciences Center, Ljubljana, Slovenia; and Centre National de la Recherche Scientifique (CNRS)-UMR7101, IFR-83, Université P. & M. Curie, and Institut de Biologie-Physico-Chimique, CNRS, UPR 1929, Université Paris 7 Denis Diderot, Paris, France
منابع مشابه
Distinct role of Rab3A and Rab3B in secretory activity of rat melanotrophs.
Members of the Rab3 (A-D) subfamily of small GTPases are believed to play a key role in regulated exocytosis. These proteins share approximately 80% identity at amino acid level. The question of whether isoforms of Rab3 are functionally redundant was the subject of this study. We used RT-PCR analysis, in situ hybridization histochemistry, and confocal microscope-based analysis of immunocytochem...
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Rab3a is a small GTPase of the Rab3 subfamily that acts during late stages of Ca²⁺-regulated exocytosis. Previous functional analysis in pituitary melanotrophs described Rab3a as a positive regulator of Ca²⁺-dependent exocytosis. However, the precise role of the Rab3a isoform on the kinetics and intracellular [Ca²⁺] sensitivity of regulated exocytosis, which may affect the availability of two m...
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Rab3A, Rab3B, Rab3C, and Rab3D constitute a family of GTP-binding proteins that are implicated in regulated exocytosis. Various localizations and distinct functions have been proposed for different and occasionally even for the same Rab3 protein. This is exemplified by studies demonstrating that deletion of Rab3A in knock-out mice results in dysregulation of the final stages of exocytosis, wher...
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In this study we examined the biochemical properties and subcellular localization of Rab3A, Rab3B and Rab3C in bovine adrenal chromaffin cells. The Kd for guanosine 5'-[gamma-thio]triphosphate (GTP[S]) of the three Rab3 proteins was 15, 2700 and 204 nM for Rab3A, Rab3B and Rab3C respectively. The intrinsic GTPase activity of the three Rab3 proteins seemed similar and was increased approx. 3-fol...
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We examined the presence of small molecular mass GTP-binding proteins of the Rab3 family in different insulin-secreting cells. Rab3B and Rab3C were identified by western blotting in rat and in human pancreatic islets, in two rat insulin-secreting cell lines, RINm5F and INS-1, as well as in the hamster cell line HIT-T15. In contrast, Rab3A was detected in rat pancreatic islets as well as in the ...
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