Synthetic Probes of Protein Prenylation

蛋白质异戊烯化的合成探针：类异戊二烯脂质的共价修饰（异戊烯化）是一个关键的 参与细胞信号传导的许多蛋白质的翻译后事件。他们发现 Ras家族的原癌基因被法呢基类异戊二烯修饰（法呢基化）， 这些蛋白质的致癌形式表达其转化潜力所需的，已经导致了强烈的 蛋白法尼基转移酶（FTase）抑制剂（FTIs）作为有前途的癌症化疗药物的研究 剂.然而，最近的事态发展表明，快速道行动的作用机制出乎意料地 复杂，虽然它涉及FTase的抑制。此外，类异戊二烯脂质对整体 Ras的生物学尚不完全清楚。因此，应用基于FTase的药理学的关键是 干预是对体内法尼基化途径的彻底理解。对底物的了解 FTase的特异性和异戊二烯基部分的细胞功能对于改善未来的设计至关重要。 FTI。这项研究的中心假设是，异戊二烯基在指导后， 异戊二烯化蛋白的翻译加工和细胞膜定位。一个重要的推论是 一种假设是，对异戊二烯基结构的修饰可能导致对细胞的显著的、生物学相关的影响。 非天然异戊二烯化蛋白质的活性。我们合成了FPP类似物， 但是不能支持转换。这些分子是一类独特的潜在抗癌药物的先导 治疗剂我们称之为RFIs（Ras功能抑制剂）。该项目的具体目标是：1）具体 焦磷酸法呢酯和同源类异戊二烯香叶基香叶基的取代的非天然类似物 焦磷酸将在组合方案中合成; 2）这些化合物将被筛选为底物 或FTase和密切相关的酶香叶基香叶基转移酶I的抑制剂; 3）建立在有前途的 在这一领域的初步结果，在体内类异戊二烯的结构-功能关系将建立， 将H-Ras法尼基基团用可从在 目的1和目的2，并通过显微注射到非洲爪蟾卵母细胞中，分析其生物学功能。的 这些实验的结果将提供进一步深入了解Ras加工的机制， 转化，更好地了解H-Ras法尼基基团在体内的具体功能，并取得丰硕成果 FTI的改进方向以及可能作为RFIs的新型可转移类似物。

Synthetic Probes of Protein Prenylation: Covalent modification by isoprenoid lipids (prenylation) is a critical post-translational event for many proteins involved in cellular signaling. The discovery that the members of the Ras family of protooncogenes are modified by the farnesyl isoprenoid (farnesylation), and that prenylation is required for the oncogenic forms of these proteins to express their transforming potential, has led to intense investigation of protein-farnesyltransferase (FTase) inhibitors (FTIs) as promising cancer chemotherapeutic agents. However, recent developments have made it clear that the mechanism of FTI action is unexpectedly complex, although it involves inhibition of FTase. In addition, the contribution of isoprenoid lipids to the overall biology of Ras is incompletely understood. Therefore, a key to applying FTase-based pharmacological intervention is a thorough understanding of the in vivo farnesylation pathways. Knowledge of the substrate specifities for FTase, and the cellular function of the prenyl moiety are critical to improving the design of future FTIs. The central hypothesis of this study is that the prenyl group plays an active role in directing both post- translational processing and cellular membrane localization of prenylated proteins. An important corollary to this hypothesis is that modifications to the prenyl structure may lead to significant, biologically relevant effects on the activity of the unnaturally prenylated protein. We have synthesized FPP analogs that are transferred to oncogenic Ras but fail to support transformation. These molecules are leads for a unique class of potential anti-cancer therapeutics we term RFIs (Ras function inhibitors). The specific aims of this project are: 1) specifically substituted unnatural analogs of farnesyl pyrophosphate and the homologous isoprenoid geranylgeranyl pyrophosphate will be synthesized in a combinatorial scheme; 2) these compounds will be screened as substrates or inhibitors of FTase and the closely related enzyme geranylgeranyltransferase I; 3) building upon promising preliminary results in this area, an in vivo isoprenoid structure-function relationship will be established by replacing the H-Ras farnesyl group with a select subset of the analogs available from the studies described in specific aim 1and 2 and analyzing their biological functions following microinjection intoXenopus oocytes. The results of these experiments will provide further insight into the mechanisms of Ras processing and transformation, a greater understanding of the specific functions of the H-Ras farnesyl group in vivo, and fruitful directions for improvements in FTIs as well as novel transferable analogs which might act as RFIs.