ABCA4 Catalyzes the translocation of specific phospholipids from the extracellular/lumenal to the cytoplasmic leaflet of membrane coupled to the hydrolysis of ATP. Transports preferentially phosphatidylethanolamine. In the visual cycle, acts as an inward-directed 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. Belongs to the ABC transporter superfamily. ABCA family. Retinal-specific. Seems to be exclusively found in the rims of rod photoreceptor cells. Note: This description may include information from UniProtKB.
Protein type: Membrane protein, integral; Membrane protein, multi-pass; Transporter; Transporter, ABC family
Chromosomal Location of human Ortholog: 1p22.1
Cellular Component:  cytoplasmic vesicle; endoplasmic reticulum; intracellular membrane-bounded organelle; membrane; photoreceptor disc membrane; photoreceptor outer segment; rod photoreceptor disc membrane
Molecular Function:  11-cis retinal binding; ABC-type transporter activity; all-trans retinal binding; ATP binding; ATP hydrolysis activity; ATPase-coupled intramembrane lipid transporter activity; ATPase-coupled transmembrane transporter activity; flippase activity; GTPase activity; lipid transporter activity; N-retinylidene-phosphatidylethanolamine flippase activity; phosphatidylethanolamine flippase activity; phospholipid transporter activity; retinoid binding; retinol transmembrane transporter activity
Biological Process:  lipid transport; phospholipid transfer to membrane; phospholipid translocation; photoreceptor cell maintenance; phototransduction, visible light; retinal metabolic process; retinoid metabolic process; retinol transport; transmembrane transport; visual perception
Disease: Cone-rod Dystrophy 3; Macular Degeneration, Age-related, 2; Retinitis Pigmentosa 19; Stargardt Disease 1
Reference #:  P78363 (UniProtKB)
Alt. Names/Synonyms: ABC10; ABCA4; ABCR; ARMD2; ATP binding cassette subfamily A member 4; ATP binding cassette transporter; ATP-binding cassette sub-family A member 4; ATP-binding cassette transporter, retinal-specific; ATP-binding cassette, sub-family A (ABC1), member 4; ATP-binding transporter, retina-specific; CORD3; DKFZp781N1972; FFM; FLJ17534; photoreceptor rim protein; retina-specific ABC transporter; Retinal-specific ATP-binding cassette transporter; Retinal-specific phospholipid-transporting ATPase ABCA4; RIM ABC transporter; RIM protein; RmP; RP19; Stargardt disease protein; STGD; STGD1
Gene Symbols: ABCA4
Molecular weight: 255,944 Da
Basal Isoelectric point: 5.89  Predict pI for various phosphorylation states
Select Structure to View Below


Protein Structure Not Found.

Cross-references to other databases:  AlphaFold  |  STRING  |  cBioPortal  |  Wikipedia  |  Reactome  |  neXtProt  |  Protein Atlas  |  BioGPS  |  Pfam  |  RCSB PDB  |  Phospho.ELM  |  NetworKIN  |  UniProtKB  |  Entrez-Gene  |  GenPept  |  Ensembl Gene