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

项目概要/摘要 细胞分裂时染色体的传递过程必须仔细监测，因为错误 导致出生缺陷和不孕症，并且是癌症的一个标志。细胞使用多种机制来监测 染色体分离的过程和这些机制通常是正在开发的药物的目标 希望找到能够杀死癌细胞同时对正常细胞具有低毒性的化疗药物。的 染色体乘客复合物 (CPC) 是一种监测染色体分离的蛋白质复合物。至 为了提供其基本功能，CPC 必须在正确的地点和时间被招募到染色体上。的 将 CPC 靶向染色体的机制尚不完全清楚，但有两个关键途径已被研究 发现依赖于蛋白激酶 Haspin 和 Bub1 的活性。虽然激酶 Bub1 已被 Haspin 是一种新发现的激酶，自从作为有丝分裂检查点信号的一部分被发现以来，人们对其进行了深入研究 有关其功能和监管的基本问题尚未得到解答。更好 了解 Haspin 的功能至关重要，因为针对 Haspin 的化疗药物已显示出希望。 Haspin 具有使其抑制剂不太可能产生副作用的特性，并且多种抑制剂具有 最近显示出对多种癌症模型的功效和对正常细胞的低毒性。 迄今为止，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，这仅提供了对该分子功能的部分了解。这个提议 开发了一种新系统，使用模型生物 C. 体内研究多种细胞类型的 Haspin 功能。 线虫，具有强大的遗传和细胞生物学工具。有条件地击倒秀丽隐杆线虫 Haspin 蛋白、HASP-1，使用 CRISPR 与 HASP-1 和相关蛋白中的特定突变相结合 基因编辑，将使我们能够实现以下具体目标：1）确定 线虫不同细胞类型中 Haspin 和 Bub1 招募 CPC 的途径，2) 确定 HASP-1 招募到染色体的机制，以及 3) 确定 HASP-1 招募到染色体的机制 HASP-1 在有丝分裂和减数分裂期间被激活。我们的实验系统使我们能够解决这些问题 多种细胞类型和减数分裂的具体目标，减数分裂是一种特殊的细胞分裂，其中这些类型的机制 在其他动物系统中通常不可能进行研究。拟议的工作将为以下方面提供新的见解： 这一重要细胞周期调节剂功能的分子机制，这将对 人类健康，尤其是 Haspin 抑制剂更多地出现在临床应用中。拟议的实验将是 与本科生研究人员和学士后研究人员密切合作进行， 提高我们机构的研究能力并培训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.