title: Annexin II in exocytosis: catecholamine secretion requires the translocation of p36 to the subplasmalemmal region in chromaffin cells.
abstract: Annexin II is a Ca(2+)-dependent membrane-binding protein present in a wide variety of cells and tissues. Within cells, annexin II is found either as a 36-kD monomer (p36) or as a heterotetrameric complex (p90) coupled with the S-100-related protein, p11. Annexin II has been suggested to be involved in exocytosis as it can restore the secretory responsiveness of permeabilized chromaffin cells. By quantitative confocal immunofluorescence, immunoreplica analysis and immunoprecipitation, we show here the translocation of p36 from the cytosol to a subplasmalemmal Triton X-100 insoluble fraction in chromaffin cells following nicotinic stimulation. A synthetic peptide corresponding to the NH2-terminal domain of p36 which contains the phosphorylation sites was microinjected into individual chromaffin cells and catecholamine secretion was monitored by amperometry. This peptide blocked completely the nicotine-induced recruitment of p36 to the cell periphery and strongly inhibited exocytosis evoked by either nicotine or high K+. The light chain of annexin II, p11, was selectively expressed by adrenergic chromaffin cells, and was only present in the subplasmalemmal Triton X-100 insoluble protein fraction of both resting and stimulated cells. p11 can modify the Ca(2+)- and/or the phospholipid-binding properties of p36. We found that loss Ca2+ was required to stimulate the translocation of p36 and to trigger exocytosis in adrenergic chromaffin cells. Our findings suggest that the translocation of p36 to the subplasmalemmal region is an essential event in regulated exocytosis and support the idea that the presence of p11 in adrenergic cells may confer a higher Ca2+ affinity to the exocytotic pathway in these cells.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale U-338, Biologie de la Communication Cellulaire, Strasbourg, France.
authors.forename: S
authors.initials: S
authors.lastname: Chasserot-Golaz
authors.forename: N
authors.initials: N
authors.lastname: Vitale
authors.forename: I
authors.initials: I
authors.lastname: Sagot
authors.forename: B
authors.initials: B
authors.lastname: Delouche
authors.forename: S
authors.initials: S
authors.lastname: Dirrig
authors.forename: L A
authors.initials: LA
authors.lastname: Pradel
authors.forename: J P
authors.initials: JP
authors.lastname: Henry
authors.forename: D
authors.initials: D
authors.lastname: Aunis
authors.forename: M F
authors.initials: MF
authors.lastname: Bader
mesh_terms: D000313:Adrenal Medulla / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D017306:Annexin A2 / Q000032:analysis / Q000378:metabolism*; D001426:Bacterial Proteins; D001692:Biological Transport; D002118:Calcium / Q000494:pharmacology; D002395:Catecholamines / Q000378:metabolism*; D002417:Cattle; D002458:Cell Fractionation; D002462:Cell Membrane / Q000737:chemistry; D002463:Cell Membrane Permeability / Q000187:drug effects; D002478:Cells, Cultured; D003600:Cytosol / Q000737:chemistry; D004299:Dopamine beta-Hydroxylase / Q000032:analysis; D005089:Exocytosis / Q000502:physiology*; D008780:Methyltransferases / Q000032:analysis; D008969:Molecular Sequence Data; D009538:Nicotine / Q000494:pharmacology; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000494:pharmacology; D050918:Phosphatidylethanolamine N-Methyltransferase; D010766:Phosphorylation; D013301:Streptolysins / Q000494:pharmacology
chemical_list: D017306:Annexin A2; D001426:Bacterial Proteins; D002395:Catecholamines; D010446:Peptide Fragments; D013301:Streptolysins; C025964:streptolysin O; D009538:Nicotine; D004299:Dopamine beta-Hydroxylase; D008780:Methyltransferases; D050918:Phosphatidylethanolamine N-Methyltransferase; D002118:Calcium