Yoo Seung Hyun, So Seung Ho, Huh Yang Hoon, Park Hee Yun
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.
Ann N Y Acad Sci. 2002 Oct;971:300-10. doi: 10.1111/j.1749-6632.2002.tb04484.x.
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.
分泌颗粒是分泌细胞中主要的对肌醇三磷酸（IP(3)）敏感的细胞内钙（Ca(2+)）储存库。最近发现，分泌颗粒含有肌醇1,4,5-三磷酸受体（IP(3)R）/钙（Ca(2+)）通道的三种同工型以及高容量、低亲和力的钙（Ca(2+)）储存蛋白嗜铬粒蛋白A（CgA）和B（CgB）。IP(3)R/钙（Ca(2+)）通道在颗粒内pH 5.5时被证明可直接与CgA和CgB相互作用，这种偶联导致偶联的嗜铬粒蛋白对IP(3)R/钙（Ca(2+)）通道活性进行调节。这些结果为分泌颗粒的IP(3)介导的钙（Ca(2+)）释放机制提供了分子结构基础。
