Inositol 1,4,5-trisphosphate receptor/Ca(2+) channel modulatory role of chromogranins A and B.
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.
Yoo
Seung Hyun
SH
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
So
Seung Ho
SH
Huh
Yang Hoon
YH
Park
Hee Yun
HY
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*
D015220:Calcium Channels; D053379:Chromogranin A; D002864:Chromogranins; D053496:Inositol 1,4,5-Trisphosphate Receptors; D020033:Protein Isoforms; D018160:Receptors, Cytoplasmic and Nuclear