PROTEINS OF TELOMERE RETROTRANSPOSABLE ELEMENTS

描述：果蝇的端粒由两个长的串联阵列组成 非LTR反转录转座子、HET-A和START。在这篇文章中描述的研究 提案重点关注HET-A和HET-A编码基因的蛋白质产物 尖酸的元素。他们将检验HET-A和HET-A的产物 尖酸的Gag基因是理解这两个元素是如何被靶向的关键 特别是端粒，从而提供了关于端粒的重要信息 染色体末端的维护。HET-A和START也是 了解构成人类基因组近一半的Gag基因 典型的非LTR反转录转座子(以及HET-A的全部基因组)。HET-A 为研究非LTR型逆转录病毒提供了一个非常有利的模型 因为它在相对较高的水平上表达。它们的两面性 元素使对其蛋白质的研究具有双重信息量。这些研究 建议涉及1)酵母两个杂交实验以筛选相互作用 在HET-A Gag蛋白、Start Gag蛋白和HET-A Gag蛋白的相关组合之间 启动逆转录酶以确定它们是否能够形成 由同源多聚体或异源多聚体形成的粒子：2)RNA 寻找HET-A和/或Start RNA之间相互作用的结合实验 以及由这些元素编码的蛋白质形成核糖核蛋白颗粒 (RNP)我们已确定；3)细胞分离以分离此类RNA；4) 抗体研究以鉴定细胞学中的相关蛋白质 制剂和细胞组分；5)酵母双杂交筛选蛋白质 可能与HET-A和START蛋白相互作用来识别蛋白质 可能参与靶向这些元件的染色体末端蛋白 到端粒。

DESCRIPTION: Drosophila telomeres are formed of long tandem arrays of two non-LTR retrotransposons, HeT-A and TART. The studies described in this proposal focus on the protein products of the genes encoded by the HeT-A and TART elements. They will test the hypothesis that products of the HeT-A and TART gag genes are key to understanding how these two elements are targeted specifically to telomeres and thus give important information on the maintenance of chromosome ends. HeT-A and TART are also models for understanding the gag gene that makes up nearly half the genome of the typical non-LTR retrotransposon (and all of the genome of HeT-A). HeT-A offers an exceptionally favorable model for study of non-LTR retroelements because it is expressed at relatively high levels. The dual nature of these elements makes study of their proteins doubly informative. The studies proposed involve 1) yeast two hybrid experiments to screen for interactions between relevant combinations of HeT-A gag proteins, TART gag proteins, and TART reverse transcriptase to determine whether they are capable of forming particles by either homomultimerization or heteromultimerization: 2) RNA binding experiments looking for interactions between HeT-A and/or TART RNA and proteins encoded by these elements to form ribonucleoprotein particles (RNP) we have identified; 3) cell fractionation to isolate such RNAs; 4) antibody studies to identify relevant proteins both in cytological preparations and in cell fractions; 5) yeast two-hybrid screens for proteins interacting with HeT-A and TART proteins to identify proteins, perhaps chromosomal end proteins that might be involved in targeting these elements to telomeres.