Gene expression of the phosducin-like protein in the retina.

Phosducin, which is expressed abundantly in the retina, mediates phototransduction or signal transduction cascades by interacting with transducin or G-protein beta gamma-subunits. We have reported on the possibility that phosducin is expressed from a multiple gene family and that each phosducin may mediate G-protein-coupled signal transduction cascades. To elucidate new genes that may mediate signal transduction cascades in the retina and that may form a gene family with phosducin, we screened a bovine retinal cDNA library. During the screening, we identified a cDNA that looked the same as the phosducin-like protein of the rat, as reported by other investigators. We examined the gene expression in rat retina using semiquantitative polymerase chain reaction and compared it to that of other organs. One form generated by alternative splicing expressed in the retina was the same as in other tissues, but, interestingly, another form had differing tissue distribution and was expressed abundantly in the retina.