TY - JOUR T1 - Human rod photoreceptor cGMP-gated channel: amino acid sequence, gene structure, and functional expression JF - The Journal of Neuroscience JO - J. Neurosci. SP - 3248 LP - 3256 DO - 10.1523/JNEUROSCI.12-08-03248.1992 VL - 12 IS - 8 AU - RS Dhallan AU - JP Macke AU - RL Eddy AU - TB Shows AU - RR Reed AU - KW Yau AU - J Nathans Y1 - 1992/08/01 UR - http://www.jneurosci.org/content/12/8/3248.abstract N2 - Phototransduction in retinal rods involves a G-protein-mediated signaling cascade that leads to cGMP hydrolysis and the closure of a cGMP-gated channel. This channel has recently been purified from bovine retina and molecularly cloned (Kaupp et al., 1989). We report here the cloning of cDNA and genomic DNA encoding the human rod cGMP-gated channel, based upon its homology to the bovine counterpart. The human mRNA structure differs from the bovine in containing an Alu repetitive element spliced into the 5′ untranslated region. The human cGMP-gated channel gene (CNCG) is located on chromosome 4 and contains at least 10 exons. One large exon encodes the carboxy-terminal two-thirds of the protein, whereas seven small exons encode the amino-terminal one-third of the protein. Alternative splicing removes one of the small exons in a subset of transcripts in the human retina, producing an internal in- frame deletion of 36 codons. When expressed in a human embryonic kidney cell line (293S), the full-length cDNA clone, but not the differentially spliced variant, produced functional ion channels broadly similar to the native channels in vertebrate rods. ER -