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Science 20 June 1986:
Vol. 232. no. 4757, pp. 1543 - 1545
DOI: 10.1126/science.3487116
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Articles

Science, Vol 232, Issue 4757, 1543-1545
Copyright © 1986 by American Association for the Advancement of Science

articles

Blockade of visual excitation and adaptation in Limulus photoreceptor by GDP-beta-S

A Fein

Light causes both depolarization and adaptation to light in Limulus ventral photoreceptors. Both visual excitation and adaptation were blocked by guanosine 5'-O-(2-thiodiphosphate) (GDP-beta-S), a metabolically stable analog of guanosine 5'-diphosphate (GDP). However, GDP-beta-S did not block the excitation caused by injection of inositol 1,4,5-trisphosphate into the cell. These results suggest a molecular cascade of visual excitation and adaptation: Light isomerizes the visual pigment rhodopsin, which in turn activates a guanyl nucleotide-binding protein. The binding protein then stimulates production of inositol 1,4,5-trisphosphate, which causes release of calcium from the endoplasmic reticulum.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Rapid Coupling of Calcium Release to Depolarization in Limulus polyphemus Ventral Photoreceptors as Revealed by Microphotolysis and Confocal Microscopy.
K. Ukhanov and R. Payne (1997)
J. Neurosci. 17, 1701-1709
   Abstract »    Full Text »    PDF »
G Protein Control of Drosophila Photoreceptor Phospholipase C.
J. L. R. Deer, J. B. Hurley, and S. L. Yarfitz (1995)
J. Biol. Chem. 270, 12623-12628
   Abstract »    Full Text »    PDF »
Purification, Characterization, and Partial Amino Acid Sequence of a G Protein-activated Phospholipase C from Squid Photoreceptors.
J. Mitchell, J. Gutierrez, and J. K. Northup (1995)
J. Biol. Chem. 270, 854-859
   Abstract »    Full Text »    PDF »


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