Journal
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Volume 23, Issue 22, Pages -Publisher
MDPI
DOI: 10.3390/ijms232214143
Keywords
CNGA1; CNGB1; photoreceptor; retina; calmodulin; phototransduction
Funding
- National Institutes of Health [R01 EY012347]
Ask authors/readers for more resources
Retinal cyclic nucleotide-gated (CNG) ion channels play a crucial role in visual phototransduction. This review discusses the binding of calmodulin to CNGB1 subunits and its impact on channel desensitization and retinal disease.
Retinal cyclic nucleotide-gated (CNG) ion channels bind to intracellular cGMP and mediate visual phototransduction in photoreceptor rod and cone cells. Retinal rod CNG channels form hetero-tetramers comprised of three CNGA1 and one CNGB1 protein subunits. Cone CNG channels are similar tetramers consisting of three CNGA3 and one CNGB3 subunits. Calmodulin (CaM) binds to two distinct sites (CaM1: residues 565-587 and CaM2: residues 1120-1147) within the cytosolic domains of rod CNGB1. The binding of Ca2+-bound CaM to CNGB1 promotes the Ca2+-induced desensitization of CNG channels in retinal rods that may be important for photoreceptor light adaptation. Mutations that affect Ca2+-dependent CNG channel function are responsible for inherited forms of blindness. In this review, we propose structural models of the rod CNG channel bound to CaM that suggest how CaM might cause channel desensitization and how dysregulation of the channel may lead to retinal disease.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available