ROLE OF THE ANTIZYME FAMILY DURING XENOPUS DEVELOPMENT

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目及 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者的研究机构。 多胺是带电的有机分子，对细胞中的大分子反应至关重要，但在高水平下是有毒的。 多胺合成酶和多胺催化酶都存在调节良好的生物合成途径。 抗酶（AZ）是一种参与控制多胺水平的蛋白质，在调节细胞中多胺水平中起作用。 AZ通过直接结合和靶向降解ODC抑制多胺摄取和限速酶鸟氨酸脱羧酶（ODC）的活性，将多胺降低至毒性水平以下。 通过了解AZ在正常环境中的功能，可以更好地了解AZ在疾病环境中的作用，并确定其在控制细胞增殖中的毒性性质。 芽殖酵母是研究多胺的一种较好的生物。 酵母中多胺合成的调节已经被描述，尽管没有具体描述抗酶在该过程中的作用。 此外，哺乳动物形式的多胺基因可以补充其在酵母细胞中的功能等同物。 使用酵母遗传筛选，可以分离和表征与AZ及其对ODC的调节功能性相互作用的基因。 本研究拟通过遗传筛选获得在酵母ODC/AZ通路的调控和功能中发挥作用的酵母基因。 已经设计了一种依赖于ODC酶活性的菌株。 抗酶的表达由于多胺水平的降低而导致诱导致死。 我们希望分离出能与多胺途径相互作用并逆转致死表型的酵母基因。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Polyamines are charged organic molecules that are vitally important for macromolecular reactions in cells but are toxic at high levels. There exist well-regulated biosynthetic pathways for both polyamine anabolism and catabolism. A protein involved in the control of polyamine levels, antizyme (AZ), plays a role in regulating polyamine levels in cells. AZ lowers polyamines below toxic levels by inhibiting polyamine uptake and activity of the rate-limiting enzyme ornithine decarboxylase (ODC) via direct binding and targeted degradation of ODC. By understanding the function of AZ in a normal setting, one can better understand the role of AZ in a disease setting and determine the nature of its toxicity in controlling cell proliferation. A tractable organism for polyamine research is the budding yeast Saccharomyces cerevisiae. The regulation of polyamine synthesis in yeast has been delineated although not specifically the role of antizyme in the process. In addition, mammalian forms of the polyamine genes can complement their functional equivalents in yeast cells. Using a yeast genetic screen, genes that functionally interact with AZ and its regulation of ODC can be isolated and characterized. This study proposes to use a genetic screen to obtain yeast genes that play a role in the regulation and function of the ODC/AZ pathway in yeast. A strain has been designed that is dependent on ODC enzymatic activity for viability. Expression of antizyme results in induced lethality due to lowered levels of polyamines. We hope to isolate yeast genes that can interact with the polyamine pathway and revert the lethal phenotype.