Abca4 - ATP-binding cassette, sub-family A (ABC1), member 4

The membrane-associated protein encoded by this gene is a member of the superfamily of ATP-binding cassette (ABC) transporters. ABC proteins transport various molecules across extra- and intracellular membranes. ABC genes are divided into seven distinct subfamilies (ABC1, MDR/TAP, MRP, ALD, OABP, GCN20, White). This protein is a member of the ABC1 subfamily. Members of the ABC1 subfamily comprise the only major ABC subfamily found exclusively in multicellular eukaryotes. This protein was the first of the ABC transporters to be observed in photoreceptors and may play a role in the photoresponse. Mutations in the human gene are found in patients diagnosed with Stargardt disease and are associated with retinitis pigmentosa-19 and macular degeneration age-related 2. [provided by RefSeq, Jul 2008]