caa a22 4500 469084006 CHVBK 20180323132959.0 cr unu---uuuuu 170328e19920801xx s 000 0 eng 10.1007/BF00319624 doi (NATIONALLICENCE)springer-10.1007/BF00319624 Immunolocalization of synexin (annexin VII) in adrenal chromaffin granules and chromaffin cells: evidence for a dynamic role in the secretory process [Elektronische Daten] [Gemma Kuijpers, George Lee, Harvey Pollard] Summary: Synexin (annexin VII) is a Ca2+- and phospholid-binding protein which has been proposed to play a role in Ca2+-dependent membrane fusion processes. Using a monoclonal antibody against synexin, Mab 10E7, and immunogold, we carried out a semiquantitative localization study of synexin in bovine adrenal medullary chromaffin granules, and in resting and nicotine-stimulated adrenal chromaffin cells. Isolated chromaffin granules contained very little synexin, whereas chromaffin granules aggregated with synexin (24 μg/mg) and Ca2+ (1 mM) clearly showed synexin-associated immunogold particles in the vicinity of the granule membrane (1.88 gold particles per granule profile). In isolated, cultured adrenal chromaffin cells, synexin was present in the nucleus (5.5 particles/μm2) and in the cytosol (5.3 particles/μm2), but mainly around the granule membrane in the granular cell area (11.7 particles/μm2). During the active phase of cholinergically stimulated catecholamine secretion, the amount of synexin label was reduced by 33% in the nucleus, by 23% in the cytosol, and by 51% in the granule area. The plasma membrane contained a small amount of synexin, which did not significantly change upon stimulation of the cells. We conclude that synexin is involved in the secretory process in chromaffin cells. Springer-Verlag, 1992 Chromaffin cell nationallicence Secretion nationallicence Synexin nationallicence Annexins nationallicence Membrane fusion nationallicence Ca2+-binding proteins nationallicence Bovine nationallicence Kuijpers Gemma Laboratory of Cell Biology and Genetics, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, 20892, Bethesda, MD, USA aut Lee George Laboratory of Cell Biology and Genetics, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, 20892, Bethesda, MD, USA aut Pollard Harvey Laboratory of Cell Biology and Genetics, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, 20892, Bethesda, MD, USA aut Cell and Tissue Research Springer-Verlag 269/2(1992-08-01), 323-330 0302-766X 269:2<323 1992 269 441 https://doi.org/10.1007/BF00319624 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00319624 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kuijpers Gemma Laboratory of Cell Biology and Genetics, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, 20892, Bethesda, MD, USA aut NATIONALLICENCE 700 1- Lee George Laboratory of Cell Biology and Genetics, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, 20892, Bethesda, MD, USA aut NATIONALLICENCE 700 1- Pollard Harvey Laboratory of Cell Biology and Genetics, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, 20892, Bethesda, MD, USA aut NATIONALLICENCE 773 0- Cell and Tissue Research Springer-Verlag 269/2(1992-08-01), 323-330 0302-766X 269:2<323 1992 269 441 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer