High level production and localization of bovine rod cGMP-gated cation channel subunit 1 in baculovirus-infected insect cells and Saccharomyces cerevisiae.

The cGMP-gated cation channel is responsible for the last step in the vertebrate phototransduction cascade which couples light activation of rhodopsin to a change in membrane permeability. Two different expression systems, baculovirus-infected Spodoptera frugiperda (Sf9) insect cells and Saccharomyces cerevisiae, were used for the overproduction of the cGMP-gated cation channel subunit 1 of bovine rod cells. Presence of recombinant channel protein was monitored by SDS-PAGE and Western-blot analysis. Through immunogold labeling, the heterologously expressed cation channel was found to be localized predominantly in the inner compartments of the infected insect cells and in the vacuole of recombinant yeast cells.