BEST1

This gene encodes a member of the bestrophin gene family. This small gene family is characterized by proteins with a highly conserved N-terminus with four to six transmembrane domains. Bestrophins may form chloride ion channels or may regulate voltage-gated L-type calcium-ion channels. Bestrophins are generally believed to form calcium-activated chloride-ion channels in epithelial cells but they have also been shown to be highly permeable to bicarbonate ion transport in retinal tissue. Mutations in this gene are responsible for juvenile-onset vitelliform macular dystrophy (VMD2), also known as Best macular dystrophy, in addition to adult-onset vitelliform macular dystrophy (AVMD) and other retinopathies. Alternative splicing results in multiple variants encoding distinct isoforms.[provided by RefSeq, Nov 2008]

Bestrophin 1

Forms calcium-sensitive chloride channels. Highly permeable to bicarbonate.

Chloride transmembrane transport Source: InterPro
Chloride transport Source: MGI
Detection of light stimulus involved in visual perception Source: Ensembl
Ion transmembrane transport Source: Reactome
Regulation of calcium ion transport Source: Ensembl
Transepithelial chloride transport Source: HGNC-UCL
Visual perception Source: ProtInc

Cell membrane; Basolateral cell membrane

Macular dystrophy, vitelliform, 2 (VMD2): An autosomal dominant form of macular degeneration that usually begins in childhood or adolescence. VMD2 is characterized by typical 'egg-yolk' macular lesions due to abnormal accumulation of lipofuscin within and beneath the retinal pigment epithelium cells. Progression of the disease leads to destruction of the retinal pigment epithelium and vision loss.
Retinitis pigmentosa 50 (RP50): A retinal dystrophy belonging to the group of pigmentary retinopathies. Retinitis pigmentosa is characterized by retinal pigment deposits visible on fundus examination and primary loss of rod photoreceptor cells followed by secondary loss of cone photoreceptors. Patients typically have night vision blindness and loss of midperipheral visual field. As their condition progresses, they lose their far peripheral visual field and eventually central vision as well.
Bestrophinopathy, autosomal recessive (ARB): A retinopathy characterized by loss of central vision, an absent electro-oculogram light rise, and electroretinogram anomalies.
Vitreoretinochoroidopathy, autosomal dominant (ADVIRC): A disorder characterized by vitreoretinochoroidal dystrophy. The clinical presentation is variable. VRCP may be associated with cataract, nanophthalmos, microcornea, shallow anterior chamber, and glaucoma.

Cytoplasmic: 1-25 aa
Helical: 26-46 aa
Extracellular: 47-70 aa
Helical: 71-91 aa
Cytoplasmic: 92-178 aa
Helical: 179-199 aa
Extracellular: 200-228 aa
Intramembrane: 229-249 aa
Extracellular: 250-270 aa
Helical: 271-291 aa
Cytoplasmic: 292-585 aa