Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
XB-ART-23094
Science 1992 Dec 11;2585089:1812-5.
Show Gene links Show Anatomy links

Range of messenger action of calcium ion and inositol 1,4,5-trisphosphate.

Allbritton NL , Meyer T , Stryer L .


???displayArticle.abstract???
The range of messenger action of a point source of Ca2+ or inositol 1,4,5-trisphosphate (IP3) was determined from measurements of their diffusion coefficients in a cytosolic extract from Xenopus laevis oocytes. The diffusion coefficient (D) of [3H]IP3 injected into an extract was 283 microns 2/s. D for Ca2+ increased from 13 to 65 microns 2/s when the free calcium concentration was raised from about 90 nM to 1 microM. The slow diffusion of Ca2+ in the physiologic concentration range results from its binding to slowly mobile or immobile buffers. The calculated effective ranges of free Ca2+ before it is buffered, buffered Ca2+, and IP3 determined from their diffusion coefficients and lifetimes were 0.1 micron, 5 microns, and 24 microns, respectively. Thus, for a transient point source of messenger in cells smaller than 20 microns, IP3 is a global messenger, whereas Ca2+ acts in restricted domains.

???displayArticle.pubmedLink??? 1465619
???displayArticle.link??? Science
???displayArticle.grants??? [+]