Identification and characterization of all-trans-retinol dehydrogenase from photoreceptor outer segments, the visual cycle enzyme that reduces all-trans-retinal to all-trans-retinol
Identification and characterization of all-trans-retinol dehydrogenase from photoreceptor outer segments, the visual cycle enzyme that reduces all-trans-retinal to all-trans-retinol
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DOI：
10.1074/jbc.275.15.11034
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发表时间：
2000-04-14
影响因子：
4.8
通讯作者：
Nathans, J
中科院分区：
文献类型：
--
作者：
Rattner, A;Smallwood, PM;Nathans, J
视黄醇脱氢酶 (RDH) 是一种催化光感受器外节内全反式视黄醛还原为全反式视黄醇的酶，是第一个被鉴定的视觉周期酶活性。之前的研究表明，该酶利用 NADPH，相对于 11-顺式视黄醛，表现出对全反式视黄醛的明显偏好，并且与外节膜紧密相关。本文报道了利用视网膜 cDNA 高通量测序的减法和归一化以及数据库同源性搜索来检测视网膜特异性基因，鉴定了短链脱氢酶/还原酶家族的新成员光感受器 RDH (prRDH)。牛和人 prRDH 高度同源，并且与 17-β-羟基类固醇脱氢酶 1 关系最为密切。重组牛 prRDH 的酶学特性与之前报道的粗制牛棒外节制剂中 RDH 活性的特性非常匹配。原位杂交和RNA印迹显示PRRDH基因在感光细胞中特异性表达，蛋白质印迹和免疫细胞化学显示prRDH仅定位于视杆和视锥外节，并且prRDH与外节膜紧密相关。总而言之，这些数据表明 prRDH 是负责将光感受器外节内的全反式视黄醛还原为全反式视黄醇的酶。
Retinol dehydrogenase (RDH), the enzyme that catalyzes the reduction of all-trans-retinal to all-trans-retinol within the photoreceptor outer segment, was the first visual cycle enzymatic activity to be identified, Previous work has shown that this enzyme utilizes NADPH, shows a marked preference for all-trans-retinal over 11-cis-retinal, and is tightly associated with the outer segment membrane. This paper reports the identification of a novel member of the short chain dehydrogenase/reductase family, photoreceptor RDH (prRDH), using subtraction and normalization of retina cDNA high throughput sequencing, and data base homology searches to detect retina-specific genes. Bovine and human prRDH are highly homologous and are most closely related to 17-beta-hydroxysteroid dehydrogenase 1, The enzymatic properties of recombinant bovine prRDH closely match those previously reported for RDH activity in crude bovine rod outer segment preparations. In situ hybridization and RNA blotting show that the PRRDH gene is expressed specifically in photoreceptor cells, and protein blotting and immunocytochemistry show that prRDH localizes exclusively to both rod and cone outer segments and that prRDH is tightly associated with outer segment membranes. Taken together, these data indicate that prRDH is the enzyme responsible for the reduction of all-trans-retinal to all-trans-retinol within the photoreceptor outer segment.