Cyclic nucleotide-gated channel subunit alpha 1 (CNGA1)

Cyclic nucleotide-gated channel subunit alpha 1 (CNGA1) is a pore-forming subunit of the rod photoreceptor cGMP-gated ion channel, essential for the phototransduction cascade in vertebrate vision[1][2]. CNGA1 combines with beta subunits (sometimes CNGB1) to form the functional cGMP-gated cation channel of rod photoreceptors. When darkness prevails, high intracellular cGMP concentrations keep the channel open, enabling a steady influx of Na⁺ and Ca²⁺, which maintains the resting depolarized state required for neurotransmitter release. Upon light activation, cGMP concentrations decrease, closing the channel, resulting in membrane hyperpolarization and visual signal transmission. Structural studies reveal that CNGA1 has a six-transmembrane domain topology, shares similarities to voltage-gated channels while being directly regulated by cyclic nucleotides, and features unique Ca²⁺ binding/interaction mechanisms[1]. Loss-of-function mutations in CNGA1 lead to autosomal recessive retinitis pigmentosa by disrupting normal phototransduction[2].

Other names

Cyclic nucleotide-gated channel alpha-1CNG channel alpha-1CNG-1CNG1CNCG1CNCGRod photoreceptor cGMP-gated channel subunit alphacGMP-gated cation channel alpha-1Cyclic nucleotide-gated cation channel 1Cyclic nucleotide-gated channel, photoreceptorRCNCalphaRCNC1RCNCaRP49Interleukin-1 homologue

Ligand binding (cGMP > cAMP) leads to channel opening, allowing influx of cations (primarily Na⁺ and Ca²⁺) Channel gating and ion selectivity determine photoreceptor depolarization/hyperpolarization in response to light[1][3]