CNGB1 channels

Channel name CNGB11,2
Description Cyclic nucleotide-gated cation channel B subunit
Other names CNG4, CNGb1, RCNC2
Molecular information Human CNGB1a: 1245aa, NM_001297, NP_001288, chr: 16q13
Rat CNGB1a: 1339aa, NM_031809, NP_113997, chr. 19p12
Rat CNGB1b: 858aa, CAA04152, AAC19120
Mouse CNGB1b: 966aa, XM_286113, XP_286113, chr. 8 C5
Associated subunits CNGB1a assembles with CNGA1 in rod photoreceptors; CNGB1b assembles with CNGA2 and CNGA4 in olfactory neurones
Functional assays When assembled with CNGA1 or CNGA2/CNGA4: patch-clamp, calcium imaging
Current Not functional on its own
Conductance Not established
Ion selectivity Not established
Activation Not established
Inactivation Not established
Activators None
Gating inhibitors Ca2+-calmodulin (in native rod and olfactory channel)
Blockers l-cis-diltiazem binds to this subunit and inhibits the current flowing through the CNGA1/CNGB1a channel
Radioligands None
Channel distribution Rod photoreceptors, olfactory neurones, sperm
Physiological functions Ca2+-calmodulin-dependent desensitization of rod and olfactory CNG channel; required for cell surface expression of rod channel
Mutations and pathophysiology Recessive retinitis pigmentosa is caused by the G993V mutation
Pharmacological significance Not established
Comments Splice variants have been identified in various mammals; CNGB1a, the “long” isoform, contains a glutamic acid-rich protein domain (GARP); CNGB1b, the “short” isoform (858aa in rat), does not have this domain; GAR1 (315aa in rat) corresponds to the N terminus of CNGB1a; the GARP domain is involved in association with other proteins
  • aa, amino acids; chr., chromosome.

  • 1. Ardell MD, Bedsole DL, Schoborg RV, and Pittler SJ (2000) Genomic organization of the human rod photoreceptor cGMP-gated cation channel beta-subunit gene. Gene 245:311-318

  • 2. Chen TY, Peng YW, Dhallan RS, Ahamed B, Reed RR, and Yau KW (1993) A new subunit of the cyclic nucleotide-gated cation channel in retinal rods. Nature (Lond) 362:764-767