TABLE 6

CNGB3 channels

Channel name CNGB31,2
Description Cyclic nucleotide-gated cation channel B subunit
Other names CNG6, CNGb2, CCNC2
Molecular information Human: 809aa, NM_019098, NP_061971, chr. 8q21–q22
Rat: not cloned
Mouse: 694aa, NM_013927, NP_038955, chr. 4 A3
Associated subunits CNGB3 assembles with CNGA3 in cone photoreceptors
Functional assays When assembled with CNGA3: 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 modifiers None
Blockers l-cis-diltiazem binds to this subunit and inhibits the current flowing through the CNGA3/CNGB3 channel
Radioligands None
Channel distribution Cone photoreceptors, testis
Physiological functions Modulatory subunit of CNGA3, color vision
Mutations and pathophysiology Missense mutations in CNGB3 causes achromatopsia (Pingelapese blindness)
Pharmacological significance Not established
  • aa, amino acids; chr., chromosome.

  • 1. Gerstner A, Zong X, Hofmann F, and Biel M (2000) Molecular cloning and functional characterization of a new modulatory cyclic nucleotide-gated channel subunit from mouse retina. J Neurosci 20:1324-1332

  • 2. Sundin OH, Yang JM, Li Y, Zhu D, Hurd JN, Mitchell TN, Silva ED, and Maumenee IH (2000) Genetic basis of total colour blindness among the Pingelapese islanders. Nat Genet 25:289-293