ABCA4

ABCA4 ATP-binding cassette A4 transporter is an important lipid inward-turnover enzyme in retinal photoreceptor cells and retinal pigment epithelial cells. It belongs to the ATP-binding cassette ABC transporter superfamily and has a transmembrane domain and extracellular domain, as well as a nucleotide binding domain responsible for ATP binding and hydrolysis. The main function of ABCA4 is to use the energy provided by ATP to transport retinylphosphatidylethanolamine NRPE from the inner side of the outer segment membrane disk to the cytoplasmic side, maintaining the visual cycle, ensuring the effective clearance of all-trans-retinal and excess 11-cis-retinal from photoreceptor cells, and preventing the accumulation of toxic retinoid compounds. The visual cycle signaling pathway involved in ABCA4 is crucial for the health of the retina, and its loss-of-function mutations can lead to Stargardt macular degeneration and related genetic retinal diseases. Therefore, ABCA4 plays a crucial role in lipid transport and visual cycle in the visual system, and is an important target for studying and treating related retinal diseases.