Distribution profile of inositol 1,4,5-trisphosphate receptor isoforms in adrenal chromaffin cells.
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.
Huh
Yang Hoon
YH
National Creative Research Initiative Center for Secretory Granule Research, and Department of Biochemistry, Inha University College of Medicine, Jung Gu, Incheon, Republic of Korea.
Yoo
Jie Ae
JA
Bahk
Sook Jin
SJ
Yoo
Seung Hyun
SH
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
D015220:Calcium Channels; D020033:Protein Isoforms; D018160:Receptors, Cytoplasmic and Nuclear; D015544:Inositol 1,4,5-Trisphosphate