Anti-ABCA4 Antibody Picoband® Fluoro488 Conjugated

ABCA4 (ATP-Binding Cassette, Subfamily A, Member 4), also known as ABCR, is a protein which in humans is encoded by the ABCA4 gene. ABCA4 is a member of the ATP-binding cassette transporter gene sub-family A (ABC1) found exclusively in multicellular eukaryotes. Using a whole genome radiation hybrid panel, this gene is mapped to 1p21-p13. And this gene is expressed exclusively in retina photoreceptor cells, indicating the gene product mediates transport of an essental molecule across the photoreceptor cell membrane. Additionally, it is showed by immunofluorescence microscopy and Western blot analysis that ABCR is present in foveal and peripheral cone, as well as rod, photoreceptors. The results suggested that the loss in central vision experienced by patients with Stargardt macular dystrophy arises ly from ABCR-mediated foveal cone degeneration.

Retinal-specific ATP-binding cassette transporter; ATP-binding cassette sub-family A member 4; RIM ABC transporter; RIM protein; RmP; Stargardt disease protein; ABCA4; ABCR

In the visual cycle, acts as an inward-ed retinoid flipase, retinoid substrates imported by ABCA4 from the extracellular or intradiscal (rod) membrane surfaces to the cytoplasmic membrane surface are all-trans-retinaldehyde (ATR) and N-retinyl-phosphatidyl-ethanolamine (NR-PE) . Once transported to the cytoplasmic surface, ATR is reduced to vitamin A by trans- retinol dehydrogenase (tRDH) and then transferred to the retinal pigment epithelium (RPE) where it is converted to 11-cis-retinal. May play a role in photoresponse, removing ATR/NR-PE from the extracellular photoreceptor surfaces during bleach recovery. .

1. Allikmets, R., Shroyer, N. F., Singh, N., Seddon, J. M., Lewis, R. A., Bernstein, P. S., Peiffer, A., Zabriskie, N. A., Hutchinson, A., Dean, M., Lupski, J. R., Leppert, M. Mutation of the Stargardt disease gene (ABCR) in age-related macular degeneration. Science 277: 1805-1807, 1997. 2. Allikmets, R., Singh, N., Sun, H., Shroyer, N. F., Hutchinson, A., Chidambaram, A., Gerrard, B., Baird, L., Stauffer, D., Peiffer, A., Rattner, A., Smallwood, P., Li, Y., Anderson, K. L., Lewis, R. A., Nathans, J., Leppert, M., Dean, M., Lupski, J. R. A photoreceptor cell-specific ATP-binding transporter gene (ABCR) is mutated in recessive Stargardt macular dystrophy. Nature Genet. 15: 236-246, 1997. Note: Erratum: Nature Genet. 17:122 only, 1997. 3. Molday, L. L., Rabin, A. R., Molday, R. S. ABCR expression in foveal cone photoreceptors and its role in Stargardt macular dystrophy. Nature Genet. 25: 257-258, 2000.