Cyclic nucleotide–gated ion channels or CNG channels are ion channels that function in response to the binding of cyclic nucleotides. CNG channels are nonselective cation channels that are found in the membranes of various tissue and cell types, and are significant in sensory transduction as well as cellular development. Their function can be the result of a combination of the binding of cyclic nucleotides and either a depolarization or a hyperpolarization event. Initially discovered in the cells that make up the retina of the eye, CNG channels have been found in many different cell types across both the animal and the plant kingdoms. CNG channels have a very complex structure with various subunits and domains that play a critical role in their function. CNG channels are significant in the function of various sensory pathways including vision and olfaction, as well as in other key cellular functions such as hormone release and chemotaxis. CNG channels have also been found to exist in prokaryotes, including many spirochaeta, though their precise role in bacterial physiology remains unknown.
Potassium voltage-gated channel subfamily D member 2 is a protein that in humans is encoded by the KCND2 gene. It contributes to the cardiac transient outward potassium current (Ito1), the main contributing current to the repolarizing phase 1 of the cardiac action potential.
Potassium/sodium hyperpolarization-activated cyclic nucleotide-gated ion channel 2 is a protein that in humans is encoded by the HCN2 gene.
Cyclic nucleotide-gated cation channel alpha-3 is a protein that in humans is encoded by the CNGA3 gene.
Potassium voltage-gated channel subfamily H member 1 is a protein that in humans is encoded by the KCNH1 gene.
Cyclic nucleotide gated channel beta 3, also known as CNGB3, is a human gene encoding an ion channel protein.
Cyclic nucleotide-gated channel alpha 1, also known as CNGA1, is a human gene encoding an ion channel protein. Heterologously expressed CNGA1 can form a functional channel that is permeable to calcium. In rod photoreceptors, however, CNGA1 forms a heterotetramer with CNGB1 in a 3:1 ratio. The addition of the CNGB1 channel imparts altered properties including more rapid channel kinetics and greater cAMP-activated current. When light hits rod photoreceptors, cGMP concentrations decrease causing rapid closure of CNGA1/B1 channels and, therefore, hyperpolarization of the membrane potential.
Potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 4 is a protein that in humans is encoded by the HCN4 gene.
Olfactory receptor 2K2 is a protein that in humans is encoded by the OR2K2 gene.
Potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 1 is a protein that in humans is encoded by the HCN1 gene.
Cyclic nucleotide gated channel beta 1, also known as CNGB1, is a human gene encoding an ion channel protein.
Potassium voltage-gated channel, Shaw-related subfamily, member 4 (KCNC4), also known as Kv3.4, is a human gene.
Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-T2 is a protein that in humans is encoded by the GNGT2 gene.
Calcium-activated potassium channel subunit beta-4 is a protein that in humans is encoded by the KCNMB4 gene.
Potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 3 is a protein that in humans is encoded by the HCN3 gene.
Cyclic nucleotide-gated cation channel alpha-4 is a protein that in humans is encoded by the CNGA4 gene.
Potassium voltage-gated channel subfamily H member 7 is a protein that in humans is encoded by the KCNH7 gene. The protein encoded by this gene is a voltage-gated potassium channel subunit.
Mucolipin-3 also known as TRPML3 is a protein that in humans is encoded by the MCOLN3 gene. It is a member of the small family of the TRPML channels, a subgroup of the large protein family of TRP ion channels.
CatSper1, is a protein which in humans is encoded by the CATSPER1 gene. CatSper1 is a member of the cation channels of sperm family of protein. The four proteins in this family together form a Ca2+-permeant ion channel specific essential for the correct function of sperm cells.
CatSper2, is a protein which in humans is encoded by the CATSPER2 gene. CatSper2 is a member of the cation channels of sperm family of protein. The four proteins in this family together form a Ca2+-permeant ion channel specific essential for the correct function of sperm cells.
