The function and regulation of the C. elegans Haspin histone kinase homolog, HASP-1

项目摘要/摘要 细胞分裂时传递染色体的过程必须仔细监测，因为错误 导致出生缺陷和不孕不育，是癌症的标志。细胞使用各种机制来监控 染色体分离的过程和这些机制通常是正在开发的药物的靶点。 希望找到既能杀死癌细胞，又能对正常细胞低毒的化疗药物。这个 染色体乘客复合体是一种监测染色体分离的蛋白质复合体。至 提供其基本功能的CPC必须在正确的地点和时间被招募到染色体上。这个 以染色体为靶点的CPC的作用机制还不完全清楚，但有两条关键途径 发现依赖于蛋白激酶Haspin和Bub1的活性。而蛋白激酶Bub1已经 自从发现haspin作为有丝分裂检查点信号的一部分以来，人们对它进行了广泛的研究，它是一种新发现的激酶。 有关其功能和监管的根本问题尚未得到回答。更好 了解Haspin的功能至关重要，因为针对Haspin的化疗药物已经显示出希望。 Haspin具有使其抑制剂不太可能产生副作用的特征，而多种抑制剂具有 最近显示出对多种癌症模型的有效性和对正常细胞的低毒。 到目前为止，对Haspin功能的研究仅限于少数细胞类型 细胞培养中的有丝分裂，这只提供了对该分子功能的部分了解。这项建议 开发了一种新的系统，利用模式生物C. 以强大的遗传和细胞生物学工具为特色的优雅生物。有条件地击倒线虫 利用CRISPR将Hasp蛋白HASP-1与HASP-1及其相关蛋白的特定突变相结合 基因编辑，将使我们能够实现以下具体目标：1)确定相对贡献 Haspin和Bub1在线虫不同细胞类型中募集CPC的途径，2)鉴定 HASP-1被招募到染色体的机制，以及3)决定 HASP-1在有丝分裂和减数分裂过程中被激活。我们的实验系统允许我们解决这些问题 特定的目标是多种细胞类型和减数分裂，这是一种特殊的细胞分裂，这些类型的机械 在其他动物系统中进行研究通常是不可能的。拟议的工作将提供对 这种重要的细胞周期调节因子的作用的分子机制，这将对 人类健康，特别是当Haspin抑制剂在临床上出现更多的时候。拟议的实验将是 与本科生研究人员和一名毕业后的研究人员密切合作， 增强研究所的研究能力，培养下一代生物医学科学家。

Project Summary/Abstract The process of passing on chromosomes when cells divide must be carefully monitored because errors cause birth defects and infertility and are a hallmark of cancer. Cells use a variety of mechanisms to monitor the process of chromosome segregation and these mechanisms are often the target of drugs being developed in the hopes of finding chemotherapeutics that will kill cancer cells while having low toxicity to normal cells. The Chromosomal Passenger Complex (CPC) is a protein complex that monitors chromosome segregation. To provide its essential functions, the CPC must be recruited onto chromosomes at the right place and time. The mechanisms that target the CPC to chromosomes are not fully understood, but two key pathways have been discovered that rely on the activity of the protein kinases Haspin and Bub1. While the kinase Bub1 has been well studied since its discovery as part of the mitotic checkpoint signal, Haspin is a newly discovered kinase and fundamental questions abouts its function and regulation have not yet been answered. Better understanding Haspin’s function is critical because chemotherapy drugs targeting Haspin have shown promise. Haspin has features that make its inhibitors less likely to produce side effects, and multiple inhibitors have recently shown efficacy against a variety of cancer models and low toxicity to normal cells. Investigations into Haspin’s function have so far been limited to a small number of cell types undergoing mitosis in cell culture, which offers only a partial understanding of this molecule’s function. This proposal develops a new system to study Haspin function in a variety of cell types in vivo using the model organism C. elegans, which features powerful genetic and cell biological tools. Conditional knockdown of the C. elegans Haspin protein, HASP-1, combined with specific mutations in HASP-1 and associated proteins using CRISPR gene editing, will enable us to accomplish the following Specific Aims: 1) Determine the relative contribution of the Haspin and Bub1 pathways to CPC recruitment in different cell types in C. elegans, 2) Identify the mechanism by which HASP-1 is recruited to chromosomes, and 3) Determine the mechanisms by which HASP-1 becomes activated during mitosis and meiosis. Our experimental system allows us to address these Specific Aims in multiple cell types and in meiosis, a specialized cell division where these types of mechanistic studies are typically not possible in other animal systems. The proposed work will provide new insights into the molecular mechanisms underlying the function of this important cell cycle regulator, which will positively impact human health, especially as Haspin inhibitors show up more in clinical use. Proposed experiments will be performed in close collaboration with undergraduate researchers and a post-baccalaureate researcher, enhancing the research capacity of our institution and training the next generation of biomedical scientists.