3swy

Structural highlights

Disease

CNGA3_HUMAN Achromatopsia;Cone rod dystrophy. The disease is caused by mutations affecting the gene represented in this entry. Defects in CNGA3 may be a cause of Leber congenital amaurosis (LCA), a severe dystrophy of the retina, typically becoming evident in the first years of life. Visual function is usually poor and often accompanied by nystagmus, sluggish or near-absent pupillary responses, photophobia, high hyperopia and keratoconus.

Function

CNGA3_HUMAN Visual signal transduction is mediated by a G-protein coupled cascade using cGMP as second messenger. This protein can be activated by cyclic GMP which leads to an opening of the cation channel and thereby causing a depolarization of cone photoreceptors. Induced a flickering channel gating, weakened the outward rectification in the presence of extracellular calcium, increased sensitivity for L-cis diltiazem and enhanced the cAMP efficacy of the channel when coexpressed with CNGB3 (By similarity). Essential for the generation of light-evoked electrical responses in the red-, green- and blue sensitive cones.^[1]

See Also

• Ion channels 3D structures

References

1. ↑ Sundin OH, Yang JM, Li Y, Zhu D, Hurd JN, Mitchell TN, Silva ED, Maumenee IH. Genetic basis of total colourblindness among the Pingelapese islanders. Nat Genet. 2000 Jul;25(3):289-93. PMID:10888875 doi:http://dx.doi.org/10.1038/77162