Neurobiology cGMP binding sites on photoreceptor phosphodiesterase : Role in feedback regulation of visual transduction ( phototranuction / alosery / / noncatnlytic bindi stes / G protein / inhibitory subunit )

A central step in vertebrate visual transduction is the rapid drop in cGMP levels that causes cGMP-gated ion channels in the photoreceptor cell membrane to close. It has long been a puzzle that the cGMP phosphodiesterase (PDE) whose activation causes this decrease contains not only catalytic sites for cGMP hydrolysis but also noncatalytic cGMP binding sites… CONTINUE READING