POSTTRANSCRIPTIONAL MECHANISMS CONTROLLING DEVELOPMENT

控制发育的转录后机制

• 批准号: 6138677
• 负责人: RICHARD S MANN
• 金额: $ 27万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-01 至 2002-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6138677
• 关键词: DNA binding protein; DNA footprinting; Drosophilidae; SDS polyacrylamide gel electrophoresis; Xenopus oocyte; autoradiography; cofactor; developmental genetics; gene induction /repression; gene interaction; genetic enhancer element; genetic mapping; genetic regulation; genetic screening; green fluorescent proteins; histogenesis; homeobox genes; molecular cloning; molecular genetics; phenotype; polymerase chain reaction; posttranscriptional RNA processing; protein protein interaction; stoichiometry

During animal development, the various mechanisms that determine cell fates must be well coordinated. For example, long-range diffusible signaling molecules, short-range cell surface signaling molecules, and nuclear transcription factors must all function together as an integrated system. Further, these mechanisms must also operate in the context of a growing and continually changing tissue. The long-term goal of this project is to understand, in molecular terms, how such different mechanisms are integrated with each other, and with developmental time. The control of developmental pathways by the Hox genes provides an example of this problem. The Hox genes all encode DNA-binding homeodomain proteins that regulate the transcription of specific sets of downstream, target genes. Hox proteins, however, do not act alone: they bind DNA together with co-factor that increase both their binding site specificity and affinity. One well characterized family of Hox co-factors are encoded by the Drosophila extradenticle and vertebrate pbx genes. Unlike most homeodomain proteins, the Extradenticle protein is post-translationally regulated by controlling its cytoplasmic-to-nuclear translocation. Another homeodomain protein, encoded by the Drosophila homothorax gene, is required for Extradenticle's nuclear localization. In some cells, the nuclear localization of Extradenticle is controlled by diffusible signaling molecules, which, therefore, indirectly control Hox function. The work proposed is divided into four parts: the first investigates how Homothorax controls Extradenticle's nuclear localization; the second investigates Homothorax's role as a DNA-binding co-factor for the Hox proteins; and the third investigates a role for homothorax as a selector gene for antennal development. The four part proposes to use a genetic screen to identify genes that modulate Homothorax function. Parts one and two use cell biology to investigate the mechanism of Exd nuclear localization, and biochemistry to characterize critical protein-protein and protein-DNA interactions. The third and fourth parts use Drosophila genetics to investigate these problems. Characterizing these developmental mechanisms will shed light on how the vertebrate versions of these proteins, when altered, can cause cancer and human birth defects.

在动物发育过程中，确定细胞的各种机制 命运必须保持良好的协调。例如，远距离扩散 信号分子，短范围的细胞表面信号分子和 核转录因子必须全部作为整合 系统。此外，这些机制还必须在 生长和不断变化的组织。这个长期目标 项目是从分子角度理解如此不同的 机制彼此集成，并与发展时间。 HOX基因对发育途径的控制提供了一个例子 这个问题。 HOX基因都编码DNA结合同源域蛋白 调节特定的下游集合的转录 基因。但是，HOX蛋白不单独起作用：它们将DNA结合在一起 与辅助因子一起增加其结合位点的特异性和 亲和力。一个具有良好特征的HOX联合因子家族由 果蝇内部和脊椎动物PBX基因。与大多数不同 同源域蛋白，内部蛋白在后翻译上是 通过控制其细胞质至核易位来调节。其他 由果蝇基因编码的同源域蛋白是 内部核定位所需的必需品。在某些细胞中， 内部核定位由可扩散控制 信号分子，因此间接控制HOX功能。 提议的工作分为四个部分：第一个调查了如何 Hyothorax控制着内部的核定位；第二个 调查Hyothorax作为HOX的DNA结合共同因素的作用 蛋白质；第三个调查了Hyothorax作为选择者的角色 用于触角发育的基因。这四部分建议使用遗传 屏幕以识别调节同胸功能的基因。第一部分 两种使用细胞生物学来研究EXD核的机制 定位和生物化学以表征关键蛋白质蛋白质 和蛋白-DNA相互作用。第三和第四部分使用果蝇 研究这些问题的遗传学。表征这些发展 机制将阐明这些脊椎动物版本如何 蛋白质发生变化时会导致癌症和人类的先天缺陷。