OPN4

Opsins are members of the guanine nucleotide-binding protein (G protein)-coupled receptor superfamily. This gene encodes a photoreceptive opsin protein that is expressed within the ganglion and amacrine cell layers of the retina. In mouse, retinal ganglion cell axons expressing this gene projected to the suprachiasmatic nucleus and other brain nuclei involved in circadian photoentrainment. In mouse, this protein is coupled to a transient receptor potential (TRP) ion channel through a G protein signaling pathway and produces a physiologic light response via membrane depolarization and increased intracellular calcium. The protein functions as a sensory photopigment and may also have photoisomerase activity. Experiments with knockout mice indicate that this gene attenuates, but does not abolish, photoentrainment. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Jul 2008]

A protein domain is a distinct structural or functional region within a protein that can evolve, function, and exist independently of the rest of the protein chain. These domains in human OPN4 often fold into stable, three-dimensional structures and are associated with specific biological functions, such as binding to DNA, other proteins, or small molecules.

Biological processes and signaling networks where the OPN4 gene in human plays a role, providing insight into its function and relevance in health or disease.

The most significant associations for this gene, including commonly observed domains, pathway involvement, and functional highlights based on current data.

Locations within the cell where the protein is known or predicted to be active, providing insight into its function and cellular context.

Describes the biological processes, cellular components, and molecular functions associated with the human OPN4 gene, providing context for its role in the cell.