FARNESOL IS UTILIZED FOR PROTEIN ISOPRENYLATION AND THE BIOSYNTHESIS OF CHOLESTEROL IN MAMMALIAN-CELLS
FARNESOL IS UTILIZED FOR PROTEIN ISOPRENYLATION AND THE BIOSYNTHESIS OF CHOLESTEROL IN MAMMALIAN-CELLS
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DOI：
10.1006/bbrc.1995.1854
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发表时间：
1995-06-15
影响因子：
3.1
通讯作者：
WAECHTER, CJ
中科院分区：
文献类型：
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作者：
CRICK, DC;ANDRES, DA;WAECHTER, CJ
已经获得的证据表明，游离法尼醇（F-OH）可用于哺乳动物细胞中的类异戊二烯生物合成。当大鼠C6神经胶质细胞和非洲绿色猴肾细胞系（CV-1）与[H-3]F-OH一起孵育时，放射性被掺入胆固醇、泛醌（CoQ）和异戊二烯化蛋白中。在C6和CV-1细胞中，来自[H-3]F-OH的标记物掺入胆固醇中被特异性抑制焦磷酸法呢酯（F-P-P）转化为角鲨烯的角鲨烯抑制素1（SQ）阻断。这一结果强烈表明，胆固醇，可能是辅酶Q和蛋白质，是通过F-P-P代谢标记的。来自C6和CV-1细胞的脱脂蛋白质级分的SDS-PAGE分析揭示了几种标记的多肽。与通过半胱氨酸残基的异戊二烯化修饰的这些蛋白质一致，链霉蛋白酶E消化释放了具有[H-3]法尼基-半胱氨酸（F-Cys）的色谱迁移率的主要标记产物。当C6和CV-1细胞与[H-3]香叶基香叶醇（GG-OH）孵育时，标记不同的多肽组。两组蛋白质似乎都被[H-3]甲羟戊酸内酯代谢标记，并且通过链霉蛋白酶E处理从这些蛋白质中释放[H-3]标记的F-Cys和香叶基香叶基半胱氨酸（GG-Cys）。这些细胞和生物化学研究表明，F-OH可用于类异戊二烯生物合成和蛋白质异戊二烯化后，在哺乳动物细胞中被转化为F-P-P的磷酸化反应，仍有待阐明。(C)出版社：Academic Press
Evidence has been obtained indicating that free farnesol (F-OH) can be utilized for isoprenoid biosynthesis in mammalian cells. When rat C6 glial cells and an African green monkey kidney cell line (CV-1) were incubated with [H-3]F-OH, radioactivity was incorporated into cholesterol, ubiquinone (CoQ) and isoprenylated proteins. The incorporation of label from [H-3]F-OH into cholesterol in C6 and CV-1 cells was blocked by squalestatin 1 (SQ) which specifically inhibits the conversion of farnesyl pyrophosphate (F-P-P) to squalene. This result strongly suggests that cholesterol, and probably CoQ and protein, is metabolically labeled via F-P-P. SDS-PAGE analysis of the delipidated protein fractions from C6 and CV-1 cells revealed several labeled polypeptides. Consistent with these proteins being modified by isoprenylation of cysteine residues, Pronase E digestion released a major labeled product with the chromatographic mobility of [H-3]farnesyl-cysteine (F-Cys). A different set of polypeptides was labeled when C6 and CV-1 cells were incubated with [H-3]geranylgeraniol (GG-OH). Both sets of proteins appear to be metabolically labeled by [H-3]mevalonolactone, and [H-3]-labeled F-Cys and geranylgeranyl-cysteine (GG-Cys) were liberated from these proteins by Pronase E treatment. These cellular and biochemical studies indicate that F-OH can be used for isoprenoid biosynthesis and protein isoprenylation in mammalian cells after being converted to F-P-P by phosphorylation reactions that remain to be elucidated. (C) 1995 Academic Press, Inc.