Understanding ER chaperone-mediated RNR regulation

项目摘要 BiP/Kar 2是一种普遍保守的分子伴侣，位于内质网中， 细胞中的各种功能，包括新合成和变性蛋白质“客户”的蛋白质折叠 和靶向降解末端错误折叠的蛋白质。在酵母中，Kar 2的功能受辅分子伴侣的调节 例如Sec 63、Jem 1和Scj 1。虽然Scj 1和Jem 1似乎有一些多余的功能，但以前的研究表明， 已经证明了缺乏Scj 1或Jem 1的细胞之间的表型差异。Jem 1的具体作用， Scj 1在激活Kar 2和他们的特定客户组合方面仍然没有确定。 所有生物体都需要正确和准确的DNA复制才能生长和增殖。的误调节 DNA复制可导致细胞死亡或癌症。我们最近的研究揭示了Scj 1的作用， Kar 2在调节基因组完整性中的作用。虽然ER伴侣蛋白功能和基因组完整性是基本的细胞 在这些过程中，它们之间以前没有建立任何联系。 我们最近的研究表明，这种ER分子伴侣-基因组完整性连接可能是保守的， 哺乳动物细胞，因为ERdj 1（哺乳动物Kar 2的共伴侣蛋白，BiP）的缺失使细胞对DNA复制敏感 抑制剂，如三嗪和羟基脲。任何降低细胞中DNA复制速率的策略都可能 形成新的抗癌疗法的基础。 在这个提议中，我们期望获得进一步的机制洞察如何ER伴侣和合作， 分子伴侣控制DNA复制。我们建议同时使用分子生物学和最先进的质量 光谱技术在酵母和癌细胞中的应用，以实现我们建议中的目标。 这项工作的范围对与DNA复制有关的各种疾病具有广泛的影响 和ER分子伴侣的功能，包括许多类型的癌症，病毒感染和疟疾。 !

Project Summary BiP/Kar2 is a universally conserved molecular chaperone based in the endoplasmic reticulum that performs a variety of functions in the cell including protein folding of both newly synthesized and denatured protein “clients” and targeted degradation of terminally misfolded proteins. In yeast, Kar2 function is regulated by co-chaperones such as Sec63, Jem1 and Scj1. While Scj1 and Jem1 appear to have some redundant functions, previous studies have demonstrated phenotypic differences between cells lacking Scj1 or Jem1. The specific roles of Jem1 and Scj1 in activating Kar2 and their particular client portfolio remains undetermined. All organisms require correct and accurate replication of DNA to grow and proliferate. Misregulation of DNA replication can result in either cell death or cancer. Our recent studies have uncovered a role for Scj1 and Kar2 in regulating genome integrity. While ER chaperone function and genome integrity are fundamental cellular processes, no connection between them has previously been established. Our recent studies suggest that this ER chaperone-genome integrity connection may be conserved in mammalian cells as loss of ERdj1 (co-chaperone of mammalian Kar2, BiP) sensitizes cells to DNA replication inhibitors such as triapine and hydroxyurea. Any strategy that lowers the rate of DNA replication in cells may form the basis of novel anticancer therapies. In this proposal, we expect to gain further mechanistic insight into how ER chaperones and co- chaperones control DNA replication. We propose to use both molecular biology and state-of-the-art mass spectrometric techniques in and yeast and cancer cells to achieve the aims of the objectives in our proposal. The scope of this work has broad implications for a variety of diseases associated with DNA replication and ER molecular chaperone function, including many types of cancer, viral infection and malaria. !