Studies on ORC and double strand DNA break repair

ORC与双链DNA断裂修复的研究

• 批准号: 10555198
• 负责人: Anindya Dutta
• 金额: $ 35.27万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-25 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10555198
• 关键词: ASF1A gene; ATAC-seq; Affect; Basal Cell Nevus Syndrome; Binding; Bypass; CDC6 gene; CHEK1 gene; Cancer cell line; Cell Proliferation; Cell Survival; Cell physiology; Cells; Chromatin; Complement; Complex; DNA; DNA Double Strand Break; DNA Repair; DNA-PKcs; Double Strand Break Repair; Enhancers; Epigenetic Process; Eukaryota; Gene Expression; Gene Expression Regulation; Genes; Genetic; Genome Stability; Genomic Instability; Grant; Histones; Human; Individual; MCM2 gene; Maintenance; Malignant Neoplasms; Mammalian Cell; Mammals; Maps; Mediating; Molecular Chaperones; Mus; Mutagens; Nonhomologous DNA End Joining; Normal Cell; ORC1L gene; Oncogenes; Pathway interactions; Peptide Initiation Factors; Phosphorylation; Phosphotransferases; Play; Polycomb; Predisposition; Proliferating; Protein Family; Protein Kinase; Proteins; Radiation therapy; Reader; Regulation; Replication Initiation; Replication Origin; Repression; Resistance; Role; Signal Transduction; Signal Transduction Pathway; Testing; Tissues; Transformed Cell Line; Yeasts; cancer cell; cell transformation; chemotherapy; fly; helicase; inhibitor; mutant; new therapeutic target; novel; origin recognition complex; protein complex; recruit; repaired; transcriptome sequencing

REVISED ABSTRACT Replication initiation in eukaryotes is believed to be dependent on a six subunit, ATP-dependent complex of proteins, the Origin Recognition Complex (ORC), which loads the helicase MCM2-7 at origins of replication. In the last cycle of this grant we made the surprising discovery that several human cancer cell lines continue to proliferate and replicate their DNA in the absence of two important subunits of ORC, ORC1 or ORC2. This proposal will test whether cancer cell-lines survive through the action of a crippled ORC (ORC missing one subunit), or because cell transformation activates an alternate helicase-loading mechanism that allows MCM2-7 loading in the absence of the six subunit ORC. The proposal will also identify how human ORC activates and represses the compactness of the chromatin and thus regulate gene expression. It will test whether the individual subunits of ORC have functions in this regard only as the complex ORC or as individual proteins independent of the holo-ORC. The results will delineate the importance of ORC in replication initiation and maintenance of genome stability in cancer cells, identify ORC-bypass mechanisms and identify replication-independent functions of ORC in regulating cell physiology.

修订后的摘要 据信，真核生物中的复制起始依赖于六个亚基、ATP 依赖性蛋白质复合物，即起点识别复合物 (ORC)，它在复制起点加载解旋酶 MCM2-7。在本次资助的最后一个周期中，我们做出了令人惊讶的发现，即几种人类癌细胞系在缺少 ORC（ORC1 或 ORC2）两个重要亚基的情况下继续增殖和复制其 DNA。该提案将测试癌细胞系是否通过受损的 ORC（ORC 缺少一个亚基）的作用而存活，或者因为细胞转化激活了另一种解旋酶加载机制，该机制允许在缺乏六个亚基 ORC 的情况下加载 MCM2-7。该提案还将确定人类 ORC 如何激活和抑制染色质的致密性，从而调节基因表达。它将测试 ORC 的各个亚基是否仅作为复杂的 ORC 或作为独立于 Holo-ORC 的单个蛋白质具有这方面的功能。结果将描述 ORC 在癌细胞复制启动和维持基因组稳定性中的重要性，确定 ORC 旁路机制并确定 ORC 在调节细胞生理学中的复制独立功能。