title: Distribution profile of inositol 1,4,5-trisphosphate receptor isoforms in adrenal chromaffin cells.
abstract: Given the importance of inositol 1,4,5-trisphosphate receptor (IP(3)R)/Ca(2+) channels in the control of intracellular Ca(2+) concentrations, we determined the relative concentrations of the IP(3)R isoforms in subcellular organelles, based on serially sectioned electron micrographs. The endoplasmic reticulum (ER) was estimated to contain 15-20% of each of the three IP(3)R isoforms while secretory granules contained 58-69%. The nucleus contained approximately 15% each of IP(3)R-1 and -2, but 25% of IP(3)R-3, whereas the plasma membrane contained approximately 1% or less of each. These suggested that secretory granules, the nucleus and ER are at the center of IP(3)-dependent intracellular Ca(2+) control mechanisms in chromaffin cells.
authors.affiliation: National Creative Research Initiative Center for Secretory Granule Research, and Department of Biochemistry, Inha University College of Medicine, Jung Gu, Incheon, Republic of Korea.
authors.forename: Yang Hoon
authors.initials: YH
authors.lastname: Huh
authors.forename: Jie Ae
authors.initials: JA
authors.lastname: Yoo
authors.forename: Sook Jin
authors.initials: SJ
authors.lastname: Bahk
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Yoo
mesh_terms: D000311:Adrenal Glands / Q000166:cytology* / Q000648:ultrastructure; D000313:Adrenal Medulla / Q000166:cytology / Q000648:ultrastructure; D000818:Animals; D015220:Calcium Channels / Q000276:immunology / Q000378:metabolism; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D002467:Cell Nucleus / Q000378:metabolism / Q000648:ultrastructure; D019439:Chromaffin Cells / Q000378:metabolism* / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000378:metabolism / Q000648:ultrastructure; D021621:Imaging, Three-Dimensional; D007150:Immunohistochemistry; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D008954:Models, Biological; D020033:Protein Isoforms / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D022142:Secretory Vesicles / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D015220:Calcium Channels; D020033:Protein Isoforms; D018160:Receptors, Cytoplasmic and Nuclear; D015544:Inositol 1,4,5-Trisphosphate