Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.


Sci. STKE, 28 March 2000
Vol. 2000, Issue 25, p. tw3
[DOI: 10.1126/stke.2000.25.tw3]

EDITORS' CHOICE

Calcium Coordinating Calcium Release

Several mechanisms exist for releasing intracellular stores of calcium: activation of inositol trisphosphate (IP3) receptors, activation of ryanodine receptors, and stimulation of Ca2+ release by nicotinic acid adenine dinucleotide phosphate (NAADP+). Santella et al. studied calcium fluxes in starfish oocytes in response to injected caged NAADP+. Photolysis of the caged NAADP+ led to an increase in intracellular calcium [Ca2+]i that was partially blocked by the addition of both heparin (to block Ca2+ release from IP3 receptors) and 8-NH2-cyclic ADPribose (to block Ca2+ release from ryanodine receptors). The authors suggest that NAADP+ initiates an increase in [Ca2+]i that triggers further release from IP3 and ryanodine receptor-operated stores. Additionally, NAADP+ stimulated an increase in [Ca2+]i from intracellular stores in immature oocytes, but the NAADP+-stimulated increase in [Ca2+]i in mature oocytes was derived from extracellular sources of calcium, suggesting that the NAADP+-sensitive compartment fused with the plasma membrane as a consequence of oocyte maturation.

Santella, L., Kyozuka, K., Genazzani, A.A., De Riso, L., and Carafoli, E. (2000) Nicotinic acid adenine dinucleotide phosphate-induced Ca2+ release. J. Biol. Chem. 275: 8301-8306. [Abstract] [Full Text]

Citation: Coordinating Calcium Release. Sci. STKE 2000, tw3 (2000).


To Advertise     Find Products


Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882