Regulation and structure of murine malic enzyme mRNA.
Regulation and structure of murine malic enzyme mRNA.
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小鼠苹果酸酶 mRNA 的调节和结构。
DOI：
10.1111/j.1749-6632.1986.tb15522.x
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发表时间：
1986
影响因子：
5.2
通讯作者：
Rubin,CS
中科院分区：
文献类型：
--
作者：
Bagchi,S;Wise,LS;Brown,ML;Sul,HS;Bregman,D;Rubin,CS
胞浆苹果酸酶是一种同源四聚体(M=250 00O)，催化苹果酸氧化脱羧基：苹果酸+NADP*+丙酮酸+CO+NADPH+H+。该反应产生的NADPH是棕榈酸和其他长链脂肪酸从头合成所需还原当量的主要来源。因此，苹果酸酶被认为是包括ATP-柠檬酸裂解酶、脂肪酸合成酶、苹果酸酶和其他造脂酶的合成速率通常受到激素的协调调节，特定mRNA水平的饮食变化解释了饥饿/碳水化合物喂养模式下观察到的苹果酸酶、脂肪酸合成酶和ATP-柠檬酸裂解酶浓度的平行变化，从而表明控制施加在翻译前水平。Goodridge和他的同事10已经证明，当饥饿的新生鸭子被喂以高碳水化合物饲料时，苹果酸酶mRNA的稳定性和RNA酶基因的转录速度都增加了3-5倍，这决定了肝脏苹果酸酶mRNA含量净增加20倍。
Cytosolic malic enzyme is a homotetramer (M,= 250 OOO) that catalyzes the oxidative decarboxylation of malate: malate+ NADP*.+ pyruvate+ CO,+ NADPH+ H+.'NADPH produced by this reaction is a major source of the reducing equivalents necessary for the de novo biosynthesis of palmitate and other long-chain fatty acids.'Thus, malic enzyme is considered a member of a small family of" lipogenic" enzymes that includes ATP-citrate lyase, fatty acid synthetase, and acetyl-CoA carboxylase.'The rates of synthesis of malic enzyme and other lipogenic enzymes are often coordinately regulated by hormones and dietary Alterations in specific mRNA levels account for parallel changes in the concentrations of malic enzyme, fatty acid synthetase, and ATP-citrate lyase observed in a starvation/carbohydrate feeding paradigm and in response to triiodothyr~ nine,~~ thereby indicating that control is exerted at the pretranslational level. Goodridge and colleagues10 have demonstrated that 3-to 5-fold increases in both the stability of malic enzyme mRNA and rate of transcription of the rnalic enzyme gene determine a net 20-fold elevation in hepatic malic enzyme mRNA content when starved neonatal ducks are fed a high-carbohydrate diet.