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ABCA4 P78363

视网膜特异性磷脂转运ATP酶ABCA4 (EC 7.6.2.1) (ATP结合盒亚家族A成员4) (RIM ABC转运蛋白) (Rim蛋白) (RmP) (视网膜特异性ATP结合盒转运蛋白) (Stargardt病蛋白)

蛋白质信息 (UniProt)

视网膜特异性磷脂转运ATP酶ABCA4 (EC 7.6.2.1) (ATP结合盒亚家族A成员4) (RIM ABC转运蛋白) (Rim蛋白) (RmP) (视网膜特异性ATP结合盒转运蛋白) (Stargardt病蛋白)

P78363

功能描述

翻转酶,以依赖ATP的方式催化视黄醛-磷脂酰乙醇胺偶联物(如N-视黄亚基-磷脂酰乙醇胺(N-Ret-PE)的11-顺式和全反式异构体)从感光细胞外节盘膜的腔侧叶片转运至细胞质侧叶片,在此11-顺式-视黄亚基-磷脂酰乙醇胺随后异构化为全反式异构体,并被RDH8还原生成全反式视黄醇。这种转运活性确保了光激发产生的全反式视黄醛以及视紫红质和视锥视蛋白再生不需要的11-顺式视黄醛能从感光细胞中有效清除,从而防止其积累和有毒双视黄醇的形成 (PubMed:10075733, PubMed:20404325, PubMed:22735453, PubMed:23144455, PubMed:24097981, PubMed:29847635, PubMed:33375396)。在缺乏视黄醛底物的情况下,在体外显示ATP酶活性 (PubMed:33605212, PubMed:39128720, PubMed:29847635, PubMed:33375396)。可能显示GTP酶活性,该活性受脂质环境和类视黄醇化合物存在的强烈影响 (PubMed:22735453)。在缺乏ATP的情况下以高亲和力结合N-视黄亚基-磷脂酰乙醇胺的非质子化形式,而ATP结合和水解诱导蛋白构象变化,导致N-视黄亚基-磷脂酰乙醇胺释放 (By similarity)。 {ECO:0000250|UniProtKB:F1MWM0, ECO:0000269|PubMed:10075733, ECO:0000269|PubMed:20404325, ECO:0000269|PubMed:22735453, ECO:0000269|PubMed:23144455, ECO:0000269|PubMed:24097981, ECO:0000269|PubMed:29847635, ECO:0000269|PubMed:33375396, ECO:0000269|PubMed:33605212, ECO:0000269|PubMed:39128720}.

组织特异性

Retinal-specific. Seems to be exclusively found in the rims of rod photoreceptor cells.

亚细胞定位

Membrane

关键词

3D-structure Age-related macular degeneration ATP-binding Cell projection Cone-rod dystrophy Cytoplasmic vesicle Disease variant Disulfide bond Endoplasmic reticulum Glycoprotein