Gating in CNGA1 channels.
The aminoacid sequences of CNG and K(+) channels share a significant sequence identity, and it has been suggested that these channels have a common ancestral 3D architecture. However, K(+) and CNG channels have profoundly different physiological properties: indeed, K(+) channels have a high ionic selectivity, their gating strongly depends on membrane voltage and when opened by a steady depolarizing voltage several K(+) channels inactivate, whereas CNG channels have a low ion selectivity, their gating is poorly voltage dependent, and they do not desensitize in the presence of a steady concentration of cyclic nucleotides that cause their opening. The purpose of the present review is to summarize and recapitulate functional and structural differences between K(+) and CNG channels with the aim to understand the gating mechanisms of CNG channels.
Mazzolini
Monica
M
CBM S.c.r.l, Area Science Park SS 14 Km 163.5, 34012, Basovizza (TS), Trieste, Italy.
Marchesi
Arin
A
Giorgetti
Alejandro
A
Torre
Vincent
V
D000595:Amino Acid Sequence; D000818:Animals; D054815:Cyclic Nucleotide-Gated Cation Channels / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015640:Ion Channel Gating; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D015221:Potassium Channels / Q000235:genetics / Q000378:metabolism; D011487:Protein Conformation; D016415:Sequence Alignment
D054815:Cyclic Nucleotide-Gated Cation Channels; D015221:Potassium Channels