The photoreceptor rim protein is an ABC transporter encoded by the gene for recessive Stargardt's disease (ABCR).
Rim protein (RmP) is a high-Mr membrane glycoprotein that has been localized to the rims of photoreceptor outer segment discs, but its molecular identity is unknown. Here, we describe the purification of RmP and present the sequence of its mRNA. RmP is a new member of the ATP-binding cassette (ABC) transporter superfamily. We show that RmP is expressed specifically in photoreceptors and predominantly in outer segments. Further, RmP is identical to the protein recently shown to be affected in recessive Stargardt's disease. RmP is the first ABC transporter observed in photoreceptors and may play a role in the photoresponse.
Azarian
S M
SM
Department of Psychiatry and Program in Neuroscience, University of Texas Southwestern Medical Center, Dallas 75235-9111, USA.
Travis
G H
GH
D018528:ATP-Binding Cassette Transporters / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002874:Chromosome Mapping; D002878:Chromosomes, Human, Pair 1; D018076:DNA, Complementary / Q000302:isolation & purification; D005808:Genes, Recessive; D006801:Humans; D008268:Macular Degeneration / Q000235:genetics*; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification; D051379:Mice; D008969:Molecular Sequence Data; D009928:Organ Specificity; D012374:Rod Cell Outer Segment / Q000737:chemistry*
C056475:ABCA4 protein, human; D018528:ATP-Binding Cassette Transporters; C512841:Abca4 protein, mouse; D018076:DNA, Complementary; D008562:Membrane Glycoproteins