PROTEINS OF TELOMERE RETROTRANSPOSABLE ELEMENTS

描述：果蝇端粒是由两个端粒的长串联阵列形成的。 非LTR反转录转座子，HeT-A和TART。 本文中描述的研究 该提案集中在由HeT-A编码的基因的蛋白质产物上， TART元素。 他们将检验HeT-A和 TART gag基因是理解这两个元件如何靶向的关键 特别是端粒，从而提供了重要的信息 维持染色体末端。 HeT-A和TART也是 了解gag基因，它构成了近一半的基因组， 典型的非LTR反转录转座子（和HeT-A的所有基因组）。 HeT-A 为非LTR追溯元素的研究提供了一个非常有利的模型 因为它的表达水平相对较高。 这些问题的双重性质 元素使研究它们的蛋白质具有双重信息。 研究 建议涉及1）酵母双杂交实验，以筛选相互作用 HeT-A gag蛋白、TART gag蛋白和 TART逆转录酶，以确定它们是否能够形成 通过同源多聚化或异源多聚化的颗粒：2）RNA 寻找HeT-A和/或TART RNA之间相互作用的结合实验 以及由这些元件编码的蛋白质，以形成核糖核蛋白颗粒 (RNP)我们已经鉴定了; 3）细胞分级分离以分离这样的RNA; 4） 抗体研究，以确定相关的蛋白质， 制备和细胞组分中; 5）蛋白质的酵母双杂交筛选 与HeT-A和TART蛋白质相互作用以识别蛋白质， 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.