GENETIC ANALYSIS OF THE DROSOPHILA C MYC PROTEIN

描述：(申请人描述) C-myc原癌基因的表达变化在近一年中观察到 美国第七的致命性癌症，这意味着 C-myc在癌症中的作用。C-myc编码一种转录因子 基本螺旋-环状-螺旋/亮氨酸拉链类型。一个尚未解决的重大困境 了解c-Myc在癌症中的作用是如何决定其致癌作用的 功能与其作为转录调节因子的活性有关，并与其 在正常细胞中发挥作用。果蝇是一个极好的系统，在其中 在体内开展蛋白质功能的功能和遗传学研究。 此外，果蝇和果蝇蛋白质的高度结构保守性 脊椎动物提供了保证，在 果蝇很可能在人类身上执行类似的功能。发起一项 果蝇系统Myc蛋白功能的遗传分析 我们的合作者分离出了人类c-myc的果蝇同源物 基因，d-myc，并证明它对应于一种已知的 果蝇基因，小型化(Dm)。我们随后产生了额外的， 糖尿病的致命性突变。开始结构/功能分析 果蝇c-Myc同源物，我们将首先确定蛋白质的变化 与DM中新的致命突变相对应的编码序列。我们的第二个 特定的目的将决定d-myc缺失的体内后果。 使用新产生的致命的DM等位基因。合子突变体 这些等位基因不会超过第一龄幼虫的发育，而且 眼睛中的纯合子突变克隆将被标记为 细胞大小、细胞分裂、DNA复制和细胞凋亡。对以下方面的要求 D-myc在卵子发生过程中的表达将在携带 Dm突变的生殖系或毛囊细胞克隆。第三个具体目标是 这项提议将确定编码蛋白质的基因，这些蛋白质既可以调节d-Myc 表达或功能，或本身是d-Myc转录的靶标 通过对d-myc相关修饰物进行遗传筛选而产生的活性 卵巢和眼睛的表型。我们预计，这项工作不仅将 提供了一种测试关于c-Myc功能的当前假设的手段， 但也将识别新的基因和参与调控 C-Myc网络。除了提供对正常情况的有价值的见解 C-Myc的功能，我们乐观地认为治疗的新方向 将通过加强对癌症的理解来建议对癌症的干预 C-Myc调节器和效应器的组合将通过 果蝇c-Myc同源基因的遗传分析

DESCRIPTION: (Applicant's Description) Altered expression of the c-myc proto-oncogene has been observed in nearly one seventh of fatal cancers in the United States, implying a fundamental involvement of c-myc in cancer. c-myc encodes a transcription factor of the basic helix-loop-helix/leucine zipper type. A major unresolved dilemma in understanding the role of c-Myc in cancer is determining how its oncogenic function is related to its activity as a transcriptional regulator and to its function in normal cells. Drosophila melanogaster is a superb system in which to carry out functional and genetic studies of protein function in vivo. Further, the high degree of structural conservation of proteins in flies and vertebrates provides assurance that the mechanisms and genes discovered in Drosophila are likely to perform similar functions in humans. To initiate a genetic analysis of the function of Myc proteins in the Drosophila system, we and our collaborators isolated the Drosophila homologue of the human c-myc gene, d-myc, and demonstrated that it corresponds to the product of a known Drosophila gene, diminutive (dm). We have subsequently generated additional, lethal mutations in dm. To begin a structure/function analysis of the Drosophila c-Myc homolog, we will first determine the changes in the protein coding sequence that correspond to the new, lethal mutations in dm. Our second specific aim will determine the in vivo consequences of the loss of d-myc function using the newly generated lethal alleles of dm. Zygotic mutants for these alleles, which do not develop beyond the first larval instar, and homozygous mutant clones in the eye will be characterized with markers for cell size, cell division, DNA replication and apoptosis. The requirement for d-myc expression during oogenesis will be examined in females carrying germline or follicle cell clones of dm mutations. The third specific aim of this proposal will identify genes encoding proteins that either regulate d-Myc expression or function, or are themselves targets of d-Myc transcriptional activity by carrying out genetic screens for modifiers of d-myc-related phenotypes in the ovary and eye. We anticipate that this work will not only provide a means to test current hypotheses regarding the function of c-Myc, but will also identify novel genes and pathways involved in regulating the c-Myc network. In addition to providing valuable insights into the normal function of c-Myc, we are optimistic that new directions for therapeutic interventions of cancer will be suggested through the enhanced understanding of c-Myc regulators and effectors that will be achieved via the genetic analysis of the Drosophila c-Myc homolog.