title: Inositol 1,4,5-trisphosphate receptor/Ca(2+) channel modulatory role of chromogranins A and B.
abstract: The secretory granules function as the major IP(3)-sensitive intracellular Ca(2+) store of secretory cells. Recently it was found that the secretory granules contain three isoforms of inositol 1,4,5-trisphosphate receptor (IP(3)R)/Ca(2+) channels and high-capacity, low-affinity Ca(2+) storage proteins chromogranins A (CgA) and B (CgB). The IP(3)R/Ca(2+) channel was shown to directly interact with CgA and CgB at the intragranular pH 5.5, and this coupling led to modulation of the IP(3)R/Ca(2+) channel activity by the coupled chromogranins. These results provide the molecular structural basis of the IP(3)-mediated Ca(2+) release mechanism of secretory granules.
authors.affiliation: National Creative Research Initiative Center for Secretory Granule Research, Department of Biochemistry, Inha University College of Medicine,Shinheungdong 3ga, Jung Gu, Incheon 400-712, Korea. shyoo@inha.ac.kr
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Yoo
authors.forename: Seung Ho
authors.initials: SH
authors.lastname: So
authors.forename: Yang Hoon
authors.initials: YH
authors.lastname: Huh
authors.forename: Hee Yun
authors.initials: HY
authors.lastname: Park
mesh_terms: D000818:Animals; D015220:Calcium Channels / Q000737:chemistry / Q000378:metabolism*; D002417:Cattle; D053379:Chromogranin A; D002864:Chromogranins / Q000737:chemistry / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D006863:Hydrogen-Ion Concentration; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007700:Kinetics; D008954:Models, Biological; D011485:Protein Binding; D020033:Protein Isoforms; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry / Q000378:metabolism*
chemical_list: D015220:Calcium Channels; D053379:Chromogranin A; D002864:Chromogranins; D053496:Inositol 1,4,5-Trisphosphate Receptors; D020033:Protein Isoforms; D018160:Receptors, Cytoplasmic and Nuclear