Primary structure and chromosomal localization of human and mouse rod photoreceptor cGMP-gated cation channel.
We have determined the primary structures of the human and mouse retinal rod cGMP-gated cation channel by analysis of cDNA clones and amplified DNA. The open reading frames predicted polypeptides of 690 and 683 residues exhibiting 88% sequence similarity. Sequence comparison indicated that the rod channels consist of a variable 90-residue N-terminal region, a short highly charged segment rich in lysine and glutamate, and a 540-residue C-terminal portion that is well conserved in three mammalian species. Significant sequence similarity (59%) of the visual cGMP-gated channel to the olfactory cAMP-gated channel established the existence of a family of cyclic nucleotide-gated ion channel genes. RNA blot analysis revealed transcripts of 3.2 kilobases (kb) in human, mouse, and dog, 3.2, 4.6, and 5.2 kb in bovine, and 3.6 kb in fish. The human channel gene was mapped by polymerase chain reaction of somatic cell hybrid DNAs to chromosome 4 (p14-q13) near the centromere. The mouse channel gene locus (Cncg) was mapped by interspecific backcross haplotype analysis 0.9 centimorgan proximal of the Kit locus on chromosome 5.
Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas 77030.
S J
SJ
Pittler
A K
AK
Lee
M R
MR
Altherr
T A
TA
Howard
M F
MF
Seldin
R L
RL
Hurwitz
J J
JJ
Wasmuth
W
W
Baehr
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002503:Centromere / Q000502:physiology; D002874:Chromosome Mapping; D002894:Chromosomes, Human, Pair 4; D003001:Cloning, Molecular; D054815:Cyclic Nucleotide-Gated Cation Channels; D005136:Eye Proteins / Q000235:genetics*; D015723:Gene Library; D006801:Humans; D006822:Hybrid Cells; D007473:Ion Channels / Q000235:genetics*; D051379:Mice; D008809:Mice, Inbred C3H; D008969:Molecular Sequence Data; D009115:Muridae; D016366:Open Reading Frames; D010786:Photoreceptor Cells / Q000502:physiology*; D011061:Poly A / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D015183:Restriction Mapping; D012160:Retina / Q000502:physiology*; D012689:Sequence Homology, Nucleic Acid
D054815:Cyclic Nucleotide-Gated Cation Channels; D005136:Eye Proteins; D007473:Ion Channels; D012333:RNA, Messenger; D011061:Poly A