Association of the GTP-Binding Protein Rab3A with Bovine Adrenal Chromaffin Granules

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 87; no. 15; pp. 5692 - 5696
• Main Authors: Darchen, Francois, Zahraoui, Ahmed, Hammel, Frederic, Monteils, Marie-Pierre, Tavitian, Armand, Scherman, Daniel
• Format: Journal Article
• Language: English
• Published: Washington, DC National Academy of Sciences of the United States of America 01-08-1990; National Acad Sciences
• Subjects: 550201 - Biochemistry- Tracer Techniques; Adrenal Cortex - analysis; adrenal gland; ADRENAL GLANDS; Adrenal medulla; Adrenal Medulla - cytology; AMINES; Animals; ANTIBODIES; AROMATICS; AUTONOMIC NERVOUS SYSTEM AGENTS; AZAARENES; BASIC BIOLOGICAL SCIENCES; BETA DECAY RADIOISOTOPES; BIOCHEMISTRY; Biological and medical sciences; BODY; CARDIOTONICS; CARDIOVASCULAR AGENTS; CATECHOLAMINES; Cattle; Cell Fractionation; Cell membranes; Cell physiology; Cells, Cultured; Centrifugation, Density Gradient; CHEMICAL REACTIONS; CHEMISTRY; Chromaffin cells; chromaffin granules; Chromaffin Granules - analysis; Chromaffin Granules - ultrastructure; Chromaffin System - ultrastructure; Cultured cells; DAYS LIVING RADIOISOTOPES; DISTRIBUTION; DOPAMINE; DRUGS; ELECTRON CAPTURE RADIOISOTOPES; ENDOCRINE GLANDS; Endothelial cells; ENZYMES; FLUORESCENCE; Fluorescent Antibody Technique; Fundamental and applied biological sciences. Psychology; GLANDS; GTP-Binding Proteins - analysis; GTP-Binding Proteins - isolation & purification; GUANOSINE; HALOGENATION; HETEROCYCLIC COMPOUNDS; HYDROGEN COMPOUNDS; HYDROXY COMPOUNDS; HYDROXYLASES; INTERMEDIATE MASS NUCLEI; IODINATION; IODINE 125; IODINE ISOTOPES; ISOTOPE APPLICATIONS; ISOTOPES; LUMINESCENCE; MEMBRANE PROTEINS; Molecular and cellular biology; Molecular Weight; MONOCLONAL ANTIBODIES; Nerve Tissue Proteins - analysis; Nerve Tissue Proteins - isolation & purification; NEUROREGULATORS; NUCLEI; NUCLEOSIDES; NUCLEOTIDES; ODD-EVEN NUCLEI; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; ORGANS; Oxidases; OXIDOREDUCTASES; P branes; PHENOLS; POLYPHENOLS; PROTEINS; PURINES; rab3 GTP-Binding Proteins; RADIOISOTOPES; RADIORECEPTOR ASSAY; RIBOSIDES; SECRETION; Secretion. Exocytosis; SUBCELLULAR DISTRIBUTION; Subcellular Fractions - analysis; Subcellular Fractions - ultrastructure; SYMPATHOMIMETICS; TRACER TECHNIQUES; TRITIUM COMPOUNDS; Ungulates; Vesicle; Binding protein; Vertebrata; Mammalia; Bovine; Chromaffin granule; Antibody; Secretion; Artiodactyla; Catecholamine; Ungulata; Immunological method
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.87.15.5692

The Rab3A protein belongs to a large family of small GTP-binding proteins that are present in eukaryotic cells and that share amino acid identities with the Ras proteins (products of the ras protooncogenes). Rab3A, which is specifically located in nervous and endocrine tissues, is suspected to play a key role in secretion. Its localization was investigated in bovine adrenal gland by using a polyclonal antibody. Rab3A was detected in adrenal medulla but not in adrenal cortex. In cultured adrenal medulla cells, Rab3A was specifically expressed in the catecholamine-secreting chromaffin cells. Subcellular fractionation suggested that Rab3A is about 30% cytosolic and that particulate Rab3A is associated with the membrane of chromaffin granules (the catecholamine storage organelles) and with a second compartment likely to be the plasma membrane. The Rab3A localization on chromaffin granule membranes was confirmed by immunoadsorption with an antibody against dopamine β-hydroxylase. Rab3A was not extracted from this membrane by NaCl or KBr but was partially extracted by urea and totally solubilized by Triton X-100, suggesting either an interaction with an intrinsic protein or a membrane association through fatty acid acylation. This study suggests that Rab3A, which may also be located on other secretory vesicles containing noncharacterized small GTP-binding proteins, is involved in their biogenesis or in the regulated secretion process.