Photoreceptor required for image-forming vision at low light intensity. Required for photoreceptor cell viability after birth (By similarity). Light-induced isomerization of 11-cis to all-trans retinal triggers a conformational change that activates signaling via G-proteins. Subsequent receptor phosphorylation mediates displacement of the bound G-protein alpha subunit by the arrestin SAG and terminates signaling (By similarity). Homodimer (By similarity). May form a complex composed of RHO, GRK1 and RCVRN in a Ca(2+)-dependent manner; RCVRN prevents the interaction between GRK1 and RHO (By similarity). Interacts with GRK1 (By similarity). Interacts (phosphorylated form) with SAG. Interacts with GNAT1. Interacts with GNAT3. SAG and G-proteins compete for a common binding site (By similarity). Interacts with PRCD; the interaction promotes PRCD stability. Synthesized in the inner segment (IS) of rod photoreceptor cells before vectorial transport to disk membranes in the rod outer segment (OS) photosensory cilia. Phosphorylated on some or all of the serine and threonine residues present in the C-terminal region. Contains one covalently linked retinal chromophore. Upon light absorption, the covalently bound 11-cis-retinal is converted to all-trans-retinal. After hydrolysis of the Schiff base and release of the covalently bound all-trans-retinal, active rhodopsin is regenerated by binding of a fresh molecule of 11-cis-retinal. Belongs to the G-protein coupled receptor 1 family. Opsin subfamily.