Diurnal rhythm of rat liver mRNAs encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase. Correlation of functional and total mRNA levels with enzyme activity and protein.
Diurnal rhythm of rat liver mRNAs encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase. Correlation of functional and total mRNA levels with enzyme activity and protein.
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DOI：
10.1016/s0021-9258(18)90983-x
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发表时间：
1984-08
期刊：
影响因子：
--
通讯作者：
C. Clarke;A. Fogelman;P. Edwards
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文献类型：
--
作者：
C. Clarke;A. Fogelman;P. Edwards
大鼠肝脏3-羟基-3-甲基戊二酰辅酶A还原酶表现出活性的昼夜节律，其与还原酶蛋白和还原酶mRNA水平的昼夜节律一致。这种还原酶活性、多肽质量和 mRNA 的昼夜节律存在于饲喂正常饮食（未补充的大鼠饲料）的大鼠和饲喂补充考来烯胺加或减美维诺的饮食的大鼠中。通过8M尿素/十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和免疫印迹测定还原酶蛋白水平。通过肝RNA的体外翻译或印迹杂交来测量还原酶mRNA。正常饮食喂养的大鼠的功能性还原酶 mRNA 水平在黑暗周期中期比在光周期中期高约 10 倍。在喂食考来烯胺和美维诺的大鼠中观察到功能性还原酶 mRNA 的最大诱导。后者的水平比正常饮食的大鼠在昼夜最低点测得的水平高 157 倍。肝脏 RNA 的印迹杂交显示出两种主要的 mRNA，分别为 4.6 和 4.2 千碱基对，以及 6.9 千碱基对的次要 mRNA。这些 mRNA 对所有三种饮食的大鼠均表现出昼夜节律，并在 12 小时黑暗期达到峰值水平。这些数据表明还原酶质量和活性的昼夜节律与其 mRNA 的水平密切相关。
Rat liver 3-hydroxy-3-methylglutaryl coenzyme A reductase exhibits a diurnal rhythm of activity which coincides with a diurnal rhythm of reductase protein and reductase mRNA levels. This diurnal rhythm of reductase activity, polypeptide mass, and mRNA exists in rats fed a normal diet (unsupplemented rat chow) and in rats fed a diet supplemented with cholestyramine plus or minus mevinolin. Levels of reductase protein were determined by 8 M urea/sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. Reductase mRNA was measured by in vitro translation or blot hybridization of liver RNA. Functional reductase mRNA levels in rats fed a normal diet were approximately 10-fold higher during the middle of the dark cycle than during the middle of the light cycle. Maximum induction of functional reductase mRNA was observed in rats fed cholestyramine and mevinolin. This latter level was 157-fold higher than the level measured at the diurnal low point in rats fed a normal diet. Blot hybridization of liver RNA showed two predominant mRNAs of 4.6 and 4.2 kilobase pairs and a minor species at 6.9 kilobase pairs. These mRNAs exhibited a diurnal rhythm for rats on all three diets and reached peak levels during the 12-h dark period. These data indicate that the diurnal rhythm of reductase mass and activity is closely paralleled by the level of its mRNA.