CNGB1: Cyclic Nucleotide Gated Channel Subunit Beta 1
Essential component of rod photoreceptor CNG channels; mutations cause retinitis pigmentosa
Gene Information Card
| Symbol | CNGB1 |
|---|---|
| Full Name | Cyclic Nucleotide Gated Channel Subunit Beta 1 |
| Gene Type | Protein coding |
| Chromosomal Location | 16q21 |
| NCBI Gene ID | 1258 ncbi.nlm.nih.gov/gene/1258 |
| Ensembl ID | ENSG00000100030 |
| UniProt ID | Q14028 |
| OMIM ID | 600724 |
| HGNC ID | 2151 |
| Aliases | CNCG2, CNG4, GAR1, RP45, RCNC2, RCNCb |
Description
CNGB1 encodes the beta-1 subunit of the cyclic nucleotide-gated (CNG) channel in rod photoreceptors. This channel is critical for phototransduction: in darkness, cGMP keeps the channel open, allowing Na+ and Ca2+ influx; light reduces cGMP, closing the channel and hyperpolarizing the cell. CNGB1 modulates channel gating, ion selectivity, and trafficking. Loss-of-function mutations cause autosomal recessive retinitis pigmentosa (RP45) and achromatopsia-like phenotypes.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Retinitis pigmentosa 45 (RP45) | Loss-of-function mutations in CNGB1 disrupt rod CNG channel function, leading to rod photoreceptor degeneration. | OMIM #613767; ClinVar |
| Cone-rod dystrophy | Rare CNGB1 variants may impair both rod and cone CNG channels, causing progressive vision loss. | ClinVar; literature case reports |
| Achromatopsia (partial) | Biallelic CNGB1 mutations can cause incomplete achromatopsia with residual cone function. | NCBI Gene; case studies |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Retina | 0.0 (RNA-seq not applicable; protein abundant) | High (rod photoreceptors) |
| Testis | 0.0 | Not detected |
| Brain | 0.0 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Retinal pigment epithelium (ARPE-19) | 0.0 | No endogenous expression; used in overexpression studies |
| HEK293T | 0.0 | No endogenous expression; heterologous expression for electrophysiology |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.319C>T (p.Arg107*) | Nonsense | Rare | Premature stop; loss of function; associated with RP45 |
| c.1654C>T (p.Arg552*) | Nonsense | Rare | Premature stop; loss of function; reported in RP45 families |
| c.2002C>T (p.Arg668Cys) | Missense | Rare | Alters channel gating; likely pathogenic |
| c.2401delA (p.Thr801Profs*13) | Frameshift | Rare | Frameshift; loss of function; reported in RP45 |
Mutation functional classification
Loss of Function (LOF)
Majority of pathogenic CNGB1 mutations are loss-of-function (nonsense, frameshift, splice-site), leading to absent or nonfunctional CNG channel beta subunit and rod degeneration.
Gain of Function (GOF)
No gain-of-function mutations reported for CNGB1.
Dominant Negative (DN)
No dominant-negative mutations reported; all pathogenic variants are recessive.
View complete mutation data：
Gene Ontology (GO)
| • ion channel activity (GO:0005216) | • voltage-gated potassium channel complex (GO:0008076) |
| • integral component of membrane (GO:0016021) | • phototransduction (GO:0007602) |
| • protein binding (GO:0005515) | • intracellular cyclic nucleotide activated cation channel activity (GO:0005242) |
Pathways
• Phototransduction cascade (KEGG: hsa04744)
• cGMP-PKG signaling pathway (Reactome: R-HSA-418457)
Protein Summary
CNGB1 encodes the beta-1 subunit (80 kDa) of the rod CNG channel. It contains six transmembrane domains, a cyclic nucleotide-binding domain (CNBD), and a C-terminal leucine zipper. The beta subunit modulates channel gating, ion selectivity, and mediates trafficking to the outer segment. It forms a heterotetramer with three CNGA1 alpha subunits. Mutations cause retinitis pigmentosa 45.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CNGB1 Knockout HEK293 Cell Line | EDJ-KQ1804 | Human | 1258 | Details Get a Quote |
| CNGB1 Knockout HeLa Cell Line | EDJ-KQ52940 | Human | 1258 | Details Get a Quote |
| CNGB1 Knockout A-549 Cell Line | EDJ-KQ61406 | Human | 1258 | Details Get a Quote |
| CNGB1 Knockout HCT 116 Cell Line | EDJ-KQ69901 | Human | 1258 | Details Get a Quote |
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