Feedback inhibition of polyisoprenyl pyrophosphate synthesis from mevalonate in vitro. Implications for protein prenylation.
Feedback inhibition of polyisoprenyl pyrophosphate synthesis from mevalonate in vitro. Implications for protein prenylation.
复制标题
DOI：
10.1016/s0021-9258(18)42396-4
复制
发表时间：
1992-04
期刊：
影响因子：
--
通讯作者：
R. Lutz;T. McLain;M. Sinensky
中科院分区：
文献类型：
--
作者：
R. Lutz;T. McLain;M. Sinensky
蛋白质的异戊二烯化利用聚异戊二烯焦磷酸 (FPP) 和香叶基香叶基焦磷酸 (GGPP) 作为异戊二烯基供体。这些聚异戊二烯也是泛醌和多萜醇合成的前体。我们之前已经描述了兔网织红细胞裂解物中标记的甲羟戊酸对 rab 1b 的香叶基香叶基化（Khosravi-Far, R.、Lutz, R. J.、Cox, A. D.、Conroy, L.、Bourne, J. R.、Sinensky, M.、Balch, W. E.、Buss, J. C. 和 Der, C. J. (1991)美国国家科学院。 88、6264-6268）。我们现在直接证明甲羟戊酸掺入兔网织红细胞胞质中的 FPP 和 GGPP。高压液相色谱分析表明，仅合成了全反式-E,E,E-GGPP，即体内蛋白质香叶基香叶基化的异戊烯基供体。与重组 H-ras 和 rab1b 一起孵育，分别导致法尼基和香叶基香叶基衍生物的合成增加。这种增加完全是由蛋白质掺入的聚异戊二烯类化合物造成的，聚异戊二烯焦磷酸池没有变化。此外，GGPP 抑制其自身合成，而不影响 FPP 合成，在大约 3 microM GGPP 时具有半最大抑制。通过抑制异戊烯基异构酶来抑制FPP合成导致异戊烯基焦磷酸合成急剧增加。 FPP 还抑制甲羟戊酸转化为 FPP。这些发现表明，这些聚异戊二烯焦磷酸酯可以在体外下调其自身合成，并且这种调节可以控制这些聚异戊二烯类化合物在体内的水平。
The prenylation of proteins utilizes the polyisoprenyl pyrophosphates (FPP) and geranylgeranyl pyrophosphate (GGPP) as prenyl donors. These polyisoprenoids are also precursors to ubiquinone and dolichol synthesis. We have previously described the geranylgeranylation of rab 1b from labeled mevalonate in rabbit reticulocyte lysates (Khosravi-Far, R., Lutz, R. J., Cox, A. D., Conroy, L., Bourne, J. R., Sinensky, M., Balch, W. E., Buss, J. C., and Der, C. J. (1991) Proc. Natl. Acad. Sci. U.S.A. 88, 6264-6268). We now directly demonstrate the incorporation of mevalonate into FPP and GGPP in rabbit reticulocyte cytosol. High pressure liquid chromatography analysis reveals that only all-trans-E,E,E-GGPP, the prenyl donor for in vivo protein geranylgeranylation, is synthesized. Incubations with recombinant H-ras and rab1b result in an increased synthesis of farnesyl and geranylgeranyl derivatives, respectively. The increase is wholly accounted for by protein-incorporated polyisoprenoids with no change in the polyisoprenyl pyrophosphate pools. Further, GGPP inhibits its own synthesis, without affecting FPP synthesis, with half-maximal inhibition at approximately 3 microM GGPP. Inhibition of FPP synthesis by the inhibition of isopentenyl isomerase causes a dramatic increase in isopentenyl pyrophosphate synthesis. FPP also inhibits conversion of mevalonate into FPP. These findings indicate that these polyisoprenyl pyrophosphates can down-regulate their own synthesis in vitro, and this regulation may control the levels of these polyisoprenoids in vivo.