GNG4

GNG4 is a gene that encodes a protein belonging to the guanine nucleotide-binding protein (G protein) alpha subunit family. These proteins are integral components of signal transduction pathways, acting as molecular switches that transmit signals from cell surface receptors to intracellular effectors. GNG4 specifically plays a role in the visual system, particularly in the phototransduction cascade of photoreceptor cells.

The GNG4 protein is expressed in rod and cone cells, which are responsible for dim light and color vision, respectively. It interacts with other proteins in the phototransduction pathway, including rhodopsin (in rods) or cone opsins, transducin, and phosphodiesterase. When light strikes a photoreceptor, it triggers a conformational change in the opsin, which in turn activates the associated G protein. This activation leads to a cascade of events that ultimately results in a change in the cell's membrane potential, transmitting the visual signal to the brain.

Mutations or alterations in the GNG4 gene have been associated with certain types of inherited retinal diseases. These conditions can lead to progressive vision loss, affecting either night vision (nyctalopia) or color perception, and can vary in severity. Research into GNG4 and its function continues to enhance our understanding of visual processing and the molecular basis of vision disorders.