GUCY2D also known as CORD6, GUC1A4, GUC2D ROS-GC and RETGC-1, belongs to the adenylyl cyclase class-4/guanylyl cyclase family. Catalyzes the synthesis of cyclic GMP (cGMP) in rods and cones of photoreceptors. Plays an essential role in phototransduction, by mediating cGMP replenishment. May also participate in the trafficking of membrane-asociated proteins to the photoreceptor outer segment membrane.