Coupling of the IP3 receptor/Ca2+ channel with Ca2+ storage proteins chromogranins A and B in secretory granules

Seung H. Yoo

Research output: Contribution to journalReview articlepeer-review

61 Scopus citations


The secretory granules of neuroendocrine cells, which function as an inositol (1,4,5)-trisphosphate-sensitive intracellular Ca2+ store, contain both the inositol (1,4,5)-trisphosphate receptor/Ca2+ channel and the high- capacity low-affinity Ca2+ storage proteins, chromogranins A and B. Chromogranins A and B, which exist in ~2 mM range in the secretory granules, can bind 50-100 mol of Ca2+/mol with dissociation constants of 2-4 mM. These proteins interact directly with the inositol (1,4,5)-trisphosphate receptor/Ca2+ channel at the intragranular pH 5.5, not only changing the conformation of the inositol (1,4,5)-trisphosphate receptor/Ca2+ channel but also modulating the channel activity. Given the homo- and heterotetrameric existence of both the inositol (1,4,5)-trisphosphate receptor/Ca2+ channel and chromogranins A and B, these tetrameric proteins appear to interact, thus controlling the intracellular Ca2+ concentration.

Original languageEnglish (US)
Pages (from-to)424-428
Number of pages5
JournalTrends in Neurosciences
Issue number9
StatePublished - Sep 1 2000

ASJC Scopus subject areas

  • Neuroscience(all)


Dive into the research topics of 'Coupling of the IP<sub>3</sub> receptor/Ca<sup>2+</sup> channel with Ca<sup>2+</sup> storage proteins chromogranins A and B in secretory granules'. Together they form a unique fingerprint.

Cite this