Abstract
The release of Ca 2+ from intracellular stores by sub‐optimal doses of inositol trisphosphate has been shown to be dose‐related (‘quantal’), and a simple model is proposed here to account for this phenomenon. It is suggested that there is a regulatory Ca 2+ ‐binding site on, or associated with, the luminal domain of the InsP 3 receptor, which allosterically controls Ca 2+ efflux, and the affinity for Ca 2+ of that site is modulated by InsP 3 binding to the cytoplasmic domain of the receptor; a similar mechanism applied to the ryanodine receptor might also explain some aspects of Ca 2+ ‐induced Ca 2+ release. The stimulated entry of Ca 2+ into a cell which occurs upon activation of inositide‐linked receptors has been variously and confusingly proposed to be regulated by InsP 3 , InsP 4 , and/or a ‘capacitative’ Ca 2+ pool; the mechanism of InsP, receptor action suggested here is shown to lead to a potential reconciliation of all these conflicting proposals.
Keywords
Ryanodine receptorInositolReceptorBiophysicsInositol trisphosphateIntracellularChemistryInositol phosphateMechanism of actionCalciumCytoplasmBinding siteInositol trisphosphate receptorBiochemistryBiologyIn vitro
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Publication Info
- Year
- 1990
- Type
- review
- Volume
- 263
- Issue
- 1
- Pages
- 5-9
- Citations
- 740
- Access
- Closed
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Cite This
Robin F. Irvine
(1990).
‘Quanta’ Ca<sup>2+</sup> release and the control of Ca<sup>2+</sup> entry by inositol phosphates ‐ a possible mechanism.
FEBS Letters
, 263
(1)
, 5-9.
https://doi.org/10.1016/0014-5793(90)80692-c
Identifiers
- DOI
- 10.1016/0014-5793(90)80692-c