TABLE 1

CNGA1 channels

Channel name CNGA11,2,3
Description Cyclic nucleotide-gated cation channel A subunit
Other names CNG1, CNGa1, RCNC1
Molecular information Human: 690aa, NM_000087, NP_000087, chr. 4p12-cen
Rat: 683aa, NM_053497, NP_445949, chr. 14p11
Mouse: 683aa, NM_007723, NP_031749, chr. 4 C5
Associated subunits CNGB1a (rod photoreceptor channel: 3 CNGA1:1 CNGB1a)
Functional assays Patch-clamp, calcium imaging
Current Cyclic nucleotide-activated current
Conductance 25–30pS (in calcium-free solution)
Ion selectivity Ca2+ > K+ ∼ Na+
Activation Not established
Inactivation Not established
Activators cGMP ≫ cAMP (partial agonist)
Gating modifiers None
Blockers l-cis-diltiazem (in the presence of CNGB1a)
Radioligands None
Channel distribution Outer segment of rod photoreceptors, pinealocytes, some neurones
Physiological functions Light transduction (low light intensities)
Mutations and pathophysiology Missense mutations in CNGA1 cause autosomal recessive retinitis pigmentosa
Pharmacological significance Not established
  • aa, amino acids; chr., chromosome.

  • 1. Dhallan RS, Macke JP, Eddy RL, Shows TB, Reed RR, Yau KW, and Nathans J (1992) Human rod photoreceptor cGMP-gated channel: amino acid sequence, gene structure, and functional expression. J Neurosci 12:3248-3256

  • 2. Kaupp UB, Niidome T, Tanabe T, Terada S, Bonigk W, Stuhmer W, Cook NJ, Kangawa K, Matsuo H, Hirose T, et al. (1989) Primary structure and functional expression from complementary DNA of the rod photoreceptor cyclic GMP-gated channel. Nature (Lond) 342:762-766

  • 3. Pittler SJ, Lee AK, Altherr MR, Howard TA, Seldin MF, Hurwitz RL, Wasmuth JJ, and Baehr W (1992) Primary structure and chromosomal localization of human and mouse rod photoreceptor cGMP-gated cation channel. J Biol Chem 267:6257-6262