CLONING OF A CDNA FOR LIVER MICROSOMAL RETINOL DEHYDROGENASE - A TISSUE-SPECIFIC, SHORT-CHAIN ALCOHOL-DEHYDROGENASE
CLONING OF A CDNA FOR LIVER MICROSOMAL RETINOL DEHYDROGENASE - A TISSUE-SPECIFIC, SHORT-CHAIN ALCOHOL-DEHYDROGENASE
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DOI：
10.1074/jbc.270.8.3900
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发表时间：
1995-02-24
影响因子：
4.8
通讯作者：
NAPOLI, JL
中科院分区：
文献类型：
--
作者：
CHAI, XY;BOERMAN, MHEM;NAPOLI, JL
视黄酸是由视黄醇生物合成的一种激素，通过死亡调控真核生物基因表达，调控多种生物系统。这项工作报告的克隆和表达的肝cDNA编码的微粒体视黄醇脱氢酶（RoDH），催化的主要和限速步骤，在视黄酸的合成。从重组酶获得的预测的氨基酸序列和生化数据验证它是短链醇脱氢酶。与微粒体RoDH一样，重组酶被识别为与细胞视黄醇结合蛋白结合的底物视黄醇，与NADP而不是NAD具有更高的活性，被乙醇或磷脂酰胆碱刺激，不被4-甲基吡唑抑制，被氧化苯胂和甘珀酸抑制，并定位于微粒体。RoDH识别视黄醇的生理形式，全细胞视黄醇结合蛋白，其K-m为0.9 μ M，低于肝脏中类似于5 μ M浓度的全细胞视黄醇结合蛋白的值。北方和Western印迹分析显示，尽管在肝、脑、肾、肺和睾丸中有酶活性，但RoDH仅在大鼠肝中表达。这些数据表明，短链醇脱氢酶的组织特异性同工酶催化视黄酸生物合成的第一步，并进一步加强了与细胞视黄醇结合蛋白结合的视黄醇“盒"作为生理底物的证据。
Retinoic acid, a hormone biosynthesized hom retinol, controls numerous biological systems by regulating eukaryotic gene expression hom conception through death. This work reports the cloning and expression of a Liver cDNA encoding a microsomal retinol dehydrogenase (RoDH), which catalyzes the primary and rate-limiting step in retinoic acid synthesis. The predicted amino acid sequence and biochemical data obtained from the recombinant enzyme verify it as a short-chain alcohol dehydrogenase. Like microsomal RoDH, the recombinant enzyme recognized as substrate retinol bound to cellular retinol-binding protein, had higher activity with NADP rather than NAD, was stimulated by ethanol or phosphatidylcholine, was not inhibited by 4-methylpyrazole, was inhibited by phenylarsine oxide and carbenoxolone and localized to microsomes. RoDH recognized the physiological form of retinol, holocellular retinol-binding protein, with a K-m of 0.9 mu M, a value lower than the similar to 5 mu M concentration of holocellular retinol binding protein in liver. Northern and Western blot analyses revealed RoDH expression only in rat Liver, despite enzymatic activity in liver, brain, kidney, lung, and testes. These data suggest that tissue specific isozyme(s) of short chain alcohol dehydrogenases catalyze the first step in retinoic acid biogenesis and further strengthen the evidence that the ''cassette'' of retinol bound to cellular retinol-binding protein serves as a physiological substrate.