Drosophila MCM10 in DNA replication and Heterochromatin formation

描述（由申请人提供）：癌症由许多特定的疾病状态组成，所有这些疾病状态都有一个共同点：生长不受调节、分化失败和染色体生物学缺陷。染色体生物学的缺陷和细胞生长的不调节通常是DNA复制机制的错误调节和/或突变的结果。然而，越来越明显的是，癌症不仅是由经典突变驱动的，而且也是由表观遗传变化引发和维持的。表观遗传变化与基因组的核苷酸序列无关，而是核苷酸和DNA相关蛋白的修饰，从而导致基因表达的改变。这种改变的表达通常是紧密排列的DNA形成异染色质形式的结果。分开来看，DNA复制和异染色质形成都是癌症生物学的重要方面。了解这两个过程对于我们理解和治疗癌症非常重要。了解这两个过程是如何联系在一起的，有望为我们对抗癌症的持续努力增加一个新的、有用的维度。这项提议的核心目的是通过对果蝇Mcm10的研究，开始阐明DNA复制和异染色质形成是如何联系在一起的。在这个层面上对这种蛋白质的研究使我们能够开始理解DNA复制和异染色质形成之间的相互作用网络。利用新技术，我们将鉴定MCM10的多个等位基因，这将使MCM10在DNA复制和染色质生物学方面的功能分离成为可能。分析这些角色有可能导致治疗癌症的新疗法和诊断方法。为此，我们提出利用果蝇的遗传系统来探讨以下假设：果蝇DNA复制因子MCM10在DNA复制和染色质动力学中具有可分离的功能。我们将通过以下具体目标来解决这一假设：鉴定和表征果蝇MCM10 2突变体。测定MCM10等位基因对DNA复制的影响测定MCM10等位基因对染色体形态和细胞周期的影响MCM10等位基因对异染色质形成的影响确定这些MCM10等位基因与其他蛋白质相互作用的结果

DESCRIPTION (provided by applicant): Cancer consists of a multitude of specific disease states, all of which share in common: unregulated growth, failure to differentiate, and defects in chromosome biology. Defects in chromosomal biology and unregulated growth of cells are often the result of mis-regulation and/or mutations of the DNA replication machinery. However, it is becoming increasingly apparent that cancer is not driven solely by classical mutation but is also initiated and maintained by epigenetic changes. Epigenetic changes are alterations not associated with the nucleotide sequence of the genome but rather modifications of the nucleotides and DNA associated proteins that result in altered expression of genes. This altered expression is often the result of the formation of tightly packed DNA in the form of heterochromatin. Taken separately, both DNA replication and heterochromatin formation are important aspects of cancer biology. Understanding these two processes has been important for our understanding and treatment of cancer. Understanding how these two processes are linked promises to add a new and useful dimension to our ongoing efforts to confront cancer. The core aim of this proposal is to begin spell out how DNA replication and heterochromatin formation are linked through the study of Drosophila Mcm10. Study of this proteins on this level we allow us to begin to understand the network of interactions between DNA replication and heterochromatin formation. Using newly available technologies we will identify multiple alleles of MCM10 which will enable the separation of MCM10 function with respect to DNA replication and chromatin biology. Parsing these roles apart has the potential to lead to new therapies and diagnostics in treating cancer. Toward this end we propose to use the tractable genetic system Drosophila melanogaster to explore the following hypothesis: The Drosophila DNA replication factor MCM10 has separable functions in DNA replication and chromatin dynamics. We will address this hypothesis through the following specific aims: 1. Identify and characterize mutants in Drosophila MCM10 2. Assay MCM10 alleles for impacts on DNA replication 3. Assay MCM10 alleles for impacts on chromosome morphology and cell cycle 4. Assay the consequences of the MCM10 alleles on heterochromatin formation 5. Determine the consequences of these MCM10 alleles on interactions with other proteins PUBLIC HEALTH RELEVANCE: Understanding the link between how DNA is packaged appropriately and how DNA is copied will provide a broader understanding of how cancer develops in humans. Revealing the details of how these essential processes are linked will inform the diagnosis and treatment of cancer.