ATP-binding cassette, sub-family A (ABC1), member 4, also known as ABCA4 or ABCR, is a protein which in humans is encoded by the ABCA4gene.[5][6][7]
ABCA4 is a member of the ATP-binding cassette transporter gene sub-family A (ABC1) found exclusively in multicellular eukaryotes.[5] The gene was first cloned and characterized in 1997 as a gene that causes Stargardt disease, an autosomal recessive disease that causes macular degeneration.[8] The ABCA4 gene transcribes a large retina-specific protein with two transmembrane domains (TMD), two glycosylated extracellular domains (ECD), and two nucleotide-binding domains (NBD). The ABCA4 protein is almost exclusively expressed in retina localizing in outer segment disk edges of rod photoreceptors.[9]
^Allikmets R, Singh N, Sun H, Shroyer NF, Hutchinson A, Chidambaram A, Gerrard B, Baird L, Stauffer D, Peiffer A, Rattner A, Smallwood P, Li Y, Anderson KL, Lewis RA, Nathans J, Leppert M, Dean M, Lupski JR (March 1997). "A photoreceptor cell-specific ATP-binding transporter gene (ABCR) is mutated in recessive Stargardt macular dystrophy". Nature Genetics. 15 (3): 236–46. doi:10.1038/ng0397-236. PMID9054934. S2CID31677978.
^Nasonkin I, Illing M, Koehler MR, Schmid M, Molday RS, Weber BH (January 1998). "Mapping of the rod photoreceptor ABC transporter (ABCR) to 1p21-p22.1 and identification of novel mutations in Stargardt's disease". Human Genetics. 102 (1): 21–6. doi:10.1007/s004390050649. PMID9490294. S2CID22070963.