catalytic activity:H(2)CO(3) = CO(2) + H(2)O.,cofactor:Zinc.,disease:Defects in CA4 are the cause of retinitis pigmentosa type 17 (RP17) [MIM:600852]. RP leads to degeneration of retinal photoreceptor cells. 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. RP17 inheritance is autosomal dominant.,enzyme regulation:Inhibited by acetazolamide.,function:Reversible hydration of carbon dioxide. May stimulate the sodium/bicarbonate transporter activity of SLC4A4.,similarity:Belongs to the alpha-carbonic anhydrase family.,subunit:Interacts with SLC4A4.,tissue specificity:Expressed in the endothelium of the choriocapillaris in eyes (at protein level).,
Cell membrane ; Lipid-anchor, GPI-anchor .
Expressed in the endothelium of the choriocapillaris in eyes (at protein level). Not expressed in the retinal epithelium at detectable levels.