POLYCOMB-GROUP GENES AND GENE REGULATION

多梳基团基因和基因调控

• 批准号: 6179376
• 负责人: RICHARD S JONES
• 金额: $ 22.97万
• 依托单位: SOUTHERN METHODIST UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-01 至 2002-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6179376
• 关键词: DNA footprinting; Drosophilidae; alleles; developmental genetics; fusion gene; gene expression; gene induction /repression; gene interaction; genetic regulation; genetic transcription; immunocytochemistry; immunoprecipitation; molecular cloning; molecular genetics; nonmammalian vertebrate embryology; nucleic acid sequence; polymerase chain reaction; protein structure function; temperature sensitive mutant; yeast two hybrid system

The development of multicellular organisms requires that specific fates be assigned to cells and that cells "memorize" these instructions through many cycles of cell division. A well documented example involves the transcriptional regulation of the Drosophila Antennapedia (ANT-C) and bithorax (BX-C) gene complexes. The initial patterns of ANT-C and BX-C expression are controlled by transcription factors that are encoded by the segmentation genes. However, shortly after these patterns are established, the products of the segmentation genes are degraded. Maintenance of ANT-C and BX-C transcriptional activity and repression then becomes the respective responsibilities of the trithorax-group (trx-G) and Polycomb-group (Pc-G) proteins. Homologs of trx-G and Pc-G genes have been identified in a wide variety of organisms and mutations in some are associated with oncogenesis. Our long-term goal is to understand the molecular mechanisms by which the Pc-G and trx-G maintain the transcriptional states of target genes. The experiments described in this proposal are designed to better define the molecular activities of one Pc-G protein, Enhancer of zeste [E(z)]. In addition to its role in Pc-G mediated repression, E(z) may also participate in trx-G-mediated activation. E(z) protein has been shown to interact two other Pc-G proteins, and another protein that shares extensive sequence similarity with a human protein that is a component of repression complexes. Preliminary evidence suggests that several trx- G proteins are also potential E(z) binding partners. All of these interactions will be analyzed using yeast two-hybrid, in vitro binding, and co-immunoprecipitation assays. The in vivo functions of these specific protein-protein relationships will be defined through genetic analysis of E(z) transgenes bearing point mutations that specifically disrupt the respective interactions. The in vivo associations of E(z) with these and other proteins also will be examined by characterizing native E(z)-containing complexes from embryo extracts.

多细胞生物的发展需要特定的命运 并让细胞“记住”这些指令 通过细胞分裂的许多周期。 一个有据可查的例子 涉及果蝇足的转录调控 （ANT-C）和双胸（BX-C）基因复合物。 最初的模式 ANT-C和BX-C的表达受转录因子控制， 是由分割基因编码的。 然而，在这些之后不久， 建立模式，分割基因的产物被 退化了ANT-C和BX-C转录活性的维持和 然后，镇压就变成了各自的责任。 三胸组（trx-G）和多梳组（Pc-G）蛋白。的同源物 trx-G和Pc-G基因已在多种生物中被鉴定 有些基因突变与肿瘤发生有关。 我们的长期 目的是了解Pc-G和 trx-G维持靶基因的转录状态。 的 本提案中描述的实验旨在更好地定义 一种Pc-G蛋白，Zeste增强子[E（z）]的分子活性。 在 除了在Pc-G介导的抑制中的作用外，E（z）还可能 参与trx-G介导的激活。 E（z）蛋白已被证明 与另外两种蛋白质相互作用， 与人类蛋白质的广泛序列相似性， 压抑复合体的。初步证据表明，几个trx- G蛋白也是潜在的E（z）结合伴侣。 所有这些 将使用酵母双杂交，体外结合， 和免疫共沉淀分析。 这些在体内的功能 特定的蛋白质-蛋白质关系将通过遗传 分析携带点突变的E（z）转基因， 破坏各自的互动。 E（z）的体内关联 这些和其他蛋白质也将通过表征 来自胚提取物的天然含E（z）的复合物。