Catalyzes the synthesis of cyclic GMP (cGMP) in rods and cones of photoreceptors. Plays an essential role in phototransduction, by mediating cGMP replenishment (PubMed:21928830, PubMed:30319355, PubMed:26100624, PubMed:9600905, PubMed:15123990). May also participate in the trafficking of membrane-asociated proteins to the photoreceptor outer segment membrane (By similarity). GTP = 3',5'-cyclic GMP + diphosphate Activated by GUCA1A when free calcium ions concentration is low, and inhibited by GUCA1A when free calcium ions concentration is high (By similarity). Negatively regulated by RD3; inhibits the basal and GUCA1A-stimulated guanylate cyclase activity (PubMed:21928830). Homodimer; requires homodimerization for guanylyl cyclase activity (By similarity). Interacts with RD3; promotes the exit of GUCY2D from the endoplasmic reticulum and its trafficking to the photoreceptor outer segments (PubMed:21928830, PubMed:21078983). Interaction with RD3 negatively regulates guanylate cyclase activity (PubMed:21928830). Retina. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. The disease may be caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. The gene names for receptor guanylyl cyclases are inconsistent between mouse and human. The ortholog of the mouse Gucy2d gene is a pseudogene in humans. Belongs to the adenylyl cyclase class-4/guanylyl cyclase family. Retina International's Scientific Newsletter