Protein
Retinal-specific phospholipid-transporting ATPase ABCA4
Function
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.
Similarity
Belongs to the ABC transporter superfamily. ABCA family.
Sequence
MGFLRQIQLLLWKNWTLRKRQKIRFVVELVWPLSLFLVLIWLRNANPLYSQHECHFPNKAMPSAGLLPWLQGIFCNMNNPCFQNPTPGESPGTVSNYNNSILARVYRDFQELFMDTPEVQHLGQVWAELRTLSQFMDTLRTHPERFAGRGLQIRDILKDEEALTLFLMRNIGLSDSVAHLLVNSQVRVEQFAYGVPDLELTDIACSEALLQRFIIFSQRRGAQTVRDALCPLSQVTLQWIEDTLYADVDFFKLFHVLPTLLDSSSQGINLRFWGGILSDLSPRMQKFIHRPSVQDLLWVSRPLLQNGGPETFTQLMSILSDLLCGYPEGGGSRVFSFNWYEDNNYKAFLGIDSTRKDPAYSYDKRTTSFCNSLIQSLESNPLTKIAWRAAKPLLMGKILFTPDSPAARRIMKNANSTFEELDRVRKLVKAWEEVGPQIWYFFEKSTQMTVIRDTLQHPTVKDFINRQLGEEGITTEAVLNFFSNGPQEKQADDMTSFDWRDIFNITDRFLRLANQYLECLVLDKFESYDDEVQLTQRALSLLEENRFWAGVVFPGMYPWASSLPPHVKYKIRMDIDVVEKTNKIKDRYWDSGPRADPVEDFRYIWGGFAYLQDMVEQGIVKSQMQAEPPIGVYLQQMPYPCFVDDSFMIILNRCFPIFMVLAWIYSVSMTVKGIVLEKELRLKETLKNQGVSNAVIWCTWFLDSFSIMALSIFLLTLFIMHGRILHYSDPFILFLFLLAFATATIMQSFLLSTLFSKASLAAACSGVIYFTLYLPHVLCFAWQDRMTADLKTTVSLLSSVAFGFGTEYLVRFEEQGLGLQWSNIGKSPLEGDEFSFLLSMKMMLLDAALYGLLAWYLDQVFPGDYGTPLPWYFLLQESYWLGGEGCSTREERALEKTEPLTEEMEDPEHPEGMNDSFFERELPGLVPGVCVKNLVKVFEPSGRPAVDRLNITFYENQITAFLGHNGAGKTTTLSILTGLLPPTSGTVLIGGKDIETNLDVVRQSLGMCPQHNILFHHLTVAEHILFYAQLKGRSWEEAQLEMEAMLEDTGLHHKRNEEAQDLSGGMQRKLSVAIAFVGDSKVVVLDEPTSGVDPYSRRSIWDLLLKYRSGRTIIMSTHHMDEADLLGDRIAIISQGRLYCSGTPLFLKNCFGTGFYLTLVRKMKNIQSQRGGCEGVCSCTSKGFSTRCPTRVDEITEEQVLDGDVQELMDLVYHHVPEAKLVECIGQELIFLLPNKNFKQRAYASLFRELEETLADLGLSSFGISDTPLEEIFLKVTEDAGAGSMFVGGAQQKREQAGLRHPCSAPTEKLRQYAQAPHTCSPGQVDPPKGQPSPEPEDPGVPFNTGARLILQHVQALLVKRFHHTIRSRKDFVAQIVLPATFVFLALMLSIIVPPFGEFPALTLHPWMYGHQYTFFSMDEPNNEHLEVLADVLLNRPGFGNRCLKEEWLPEYPCINATSWKTPSVSPNITHLFQKQKWTAAHPSPSCKCSTREKLTMLPECPEGAGGLPPPQRTQRSTEVLQDLTNRNISDYLVKTYPALIRSSLKSKFWVNEQRYGGISIGGKLPAIPISGEALVGFLSGLGQMMNVSGGPVTREASKEMLDFLKHLETTDNIKVWFNNKGWHALVSFLNVAHNAILRASLPRDRDPEEYGITVISQPLNLTKEQLSDITVLTTSVDAVVAICVIFAMSFVPASFVLYLIQERVTKAKHLQFISGVSPTTYWLTNFLWDIMNYAVSAGLVVGIFIGFQKKAYTSPDNLPALVSLLMLYGWAVIPMMYPASFLFEVPSTAYVALSCANLFIGINSSAITFVLELFENNRTLLRFNAMLRKLLIVFPHFCLGRGLIDLALSQAVTDVYAQFGEEYSANPFQWDLIGKNLVAMAIEGVVYFLLTLLIQHHFFLTRWIAEPAREPVFDEDDDVAEERQRVMSGGNKTDILKLNELTKVYSGSSSPAVDRLCVGVRPGECFGLLGVNGAGKTTTFKMLTGDTTVTSGDATVAGKSILTSISDVHQNMGYCPQFDAIDDLLTGREHLYLYARLRGVPSKEIEKVANWGIQSLGLSLYADRLAGTYSGGNKRKLSTAIALTGCPPLLLLDEPTTGMDPQARRMLWNTIVSIIREGRAVVLTSHSMEECEALCTRLAIMVKGTFQCLGTIQHLKYKFGDGYIVTMKIKSPKDDLLPDLNPVEQFFQGNFPGSVQRERHHSMLQFQVPSSSLARIFQLLISHKDSLLIEEYSVTQTTLDQVFVNFAKQQTETYDLPLHPRAAGASWQAKLEEKSGRLQTQEPLPAGSEQLANGSNPTAAEDKHTRSPQ