MOLECULAR-CLONING, FUNCTIONAL EXPRESSION AND CHROMOSOMAL LOCALIZATIONOF A HUMAN HOMOLOG OF THE CYCLIC NUCLEOTIDE-GATED ION-CHANNEL OF RETINAL CONE PHOTORECEPTORS

We have cloned from human retina a cyclic nucleotide-gated (CNG) ion c hannel that is distinct from the one found in rod photoreceptors. This channel protein is highly homologous to the CNG channel that recently has been cloned from bovine testis and kidney and has been shown to b e present in retinal cone photoreceptors. When expressed in human embr yonic kidney cells, the protein forms functional ion channels with pro perties broadly similar to those described for the cloned bovine chann el, The gene for this channel resides on chromosome 2.