Retinal guanylate cyclase 1 (RetGC1 (commonly used), GUCY2D (gene symbol))

Retinal guanylate cyclase 1 (RetGC1), encoded by the GUCY2D gene, is a retina-specific enzyme responsible for catalyzing the synthesis of cyclic GMP from GTP in rod and cone photoreceptor cells. RetGC1 is integral to the phototransduction process, replenishing cGMP after light-induced hydrolysis to ensure proper recovery of photoreceptor cell response and visual function. Structurally, RetGC1 is a membrane-bound protein with extracellular, transmembrane, and cytoplasmic domains including a kinase-like region and a catalytic domain. Its activity is tightly regulated by calcium-binding proteins (guanylate cyclase activator proteins, GCAPs), which modulate its function in response to changes in intracellular Ca^2+ during light/dark adaptation. Pathogenic mutations in GUCY2D cause autosomal recessive retinal diseases such as Leber congenital amaurosis type 1 and cone-rod dystrophy, characterized by early-onset blindness. Therapeutic strategies for these disorders primarily focus on gene augmentation to restore RetGC1 function in affected patients

Other names

RetGC1GUCY2DRetinal guanylyl cyclase 1Retinal guanylate cyclase

Gene augmentation (gene therapy using AAV to express wild-type GUCY2D for LCA1 patients) Restoration of cGMP synthesis by supplementing or correcting defective enzyme in photoreceptors Indirect modulation of phototransduction and visual cycle