RECQ5-dependent SUMO2 conjugation of PCNA in the resolution of transcription-replication conflicts

PCNA 的 RECQ5 依赖性 SUMO2 缀合解决转录复制冲突

• 批准号: 10328909
• 负责人: Yilun Liu
• 金额: $ 38.78万
• 依托单位: BECKMAN RESEARCH INSTITUTE/CITY OF HOPE
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10328909
• 关键词: Biological Assay; Biology; Bypass; Cell Death; Cells; Chromatin; Chromosome Fragile Sites; Complex; Conflict (Psychology); DNA; DNA Damage; DNA Double Strand Break; DNA Sequence Rearrangement; DNA biosynthesis; DNA lesion; DNA replication fork; DNA-Directed DNA Polymerase; Data; Defect; Deposition; Event; Fractionation; Frequencies; Genes; Genetic Transcription; Genomic Instability; Goals; Hematopoietic Neoplasms; Histones; Human; In Vitro; Knockout Mice; Lead; Link; Lysine; Malignant Neoplasms; Mediating; Metabolic; Modeling; Modification; Molecular; Molecular Chaperones; Neoplastic Cell Transformation; Pathogenesis; Proliferating Cell Nuclear Antigen; Proteins; Proteomics; Publishing; RECQL5 gene; RNA; RNA Polymerase II; Resolution; Risk Factors; Role; S phase; Site; Solid Neoplasm; Source; Sumoylation Pathway; Transcriptional Regulation; Tumor Suppressor Proteins; Work; Xenograft procedure; base; cancer cell; cancer risk; cancer type; cell growth; cell transformation; conflict resolution; helicase; homologous recombination; in vitro Assay; innovation; member; mouse model; novel; prevent; recruit; response; transcriptome; ubiquitin-protein ligase

Project Summary Proliferating cell nuclear antigen (PCNA) is an essential component of the replisome, and it enhances the processivity of the DNA polymerases in DNA synthesis. In addition, in response to DNA damage, PCNA is ubiquitinated at lysine 164 (K164) to bypass DNA lesions. In unperturbed cells, the same K164 residue can also be conjugated with either SUMO1 or SUMO2, and SUMO1-PCNA has been implicated in recruiting PARI helicase to suppress homologous recombination. However, the source of replication obstacle that triggers PCNA SUMOylation is yet to be defined, and the regulators of PCNA SUMOylation are not known. It is also not clear if SUMO2-PCNA functions redundantly to SUMO1-PCNA. Our newly published data argue that human SUMO2-PCNA has a unique function in transcription that is not shared by SUMO1-PCNA, because only SUMO2-PCNA is associated with transcriptionally active chromatin. Even though PCNA SUMO2 conjugation occurs in S-phase, SUMO2-PCNA is induced by RNA polymerase II - dependent transcription and requires the RNA polymerase II - interacting protein, RECQ5 DNA helicase. Importantly, cells with reduced SUMO2-PCNA accumulate transcription-induced DNA double-strand breaks during S-phase. Therefore, our data support a conceptually innovative model for a role of SUMO2-PCNA in resolving transcription-replication conflicts to minimize genomic instability. The goal of this proposal is (1) to identify the molecular factors that facilitate the transcription-induced SUMO2 conjugation of PCNA, (2) to identify the molecular mechanism by which SUMO2- PCNA resolves transcription-replication conflicts, and (3) to elucidate the contribution of SUMO2-PCNA toward preventing genomic instability and neoplastic transformation, as transcription-replication conflicts are major source for common fragile site instability.

项目摘要 增殖细胞核抗原(PCNA)是复制体的重要组成部分，它能增强 DNA聚合酶在DNA合成中的加工性。此外，为了应对DNA损伤，增殖细胞核抗原是 赖氨酸164(K164)泛素化以绕过DNA损伤。在未受干扰的细胞中，相同的K164残基可以 也与SUMO1或SUMO2结合，并且SUMO1-PCNA与招募PAI有关 解旋酶抑制同源重组。然而，引发复制障碍的根源 增殖细胞核抗原SUMO化尚不明确，其调节因子也尚不清楚。它也不是 明确SUMO2-增殖细胞核抗原是否与SUMO1-增殖细胞核抗原功能冗余。我们最新公布的数据表明，人类 SUMO2-增殖细胞核抗原在转录中有一个独特的功能，这是SUMO1-增殖细胞核抗原所没有的，因为只有 SUMO2-增殖细胞核抗原与转录活性染色质相关。即使增殖细胞核抗原SUMO2接合 发生在S期，SUMO2-增殖细胞核抗原是由RNA聚合酶II依赖的转录诱导的，需要 RNA聚合酶II相互作用蛋白，RECQ5 DNA解旋酶。重要的是，SUMO2-增殖细胞核抗原降低的细胞 在S期积累转录诱导的DNA双链断裂。因此，我们的数据支持 SUMO2-增殖细胞核抗原在解决转录-复制冲突中作用的概念创新模型 将基因组的不稳定性降至最低。这项建议的目标是(1)确定促进 转录诱导的增殖细胞核抗原SUMO2结合，(2)鉴定SUMO2- 增殖细胞核抗原解决转录-复制冲突，以及(3)阐明SUMO2-增殖细胞核抗原在 防止基因组不稳定和肿瘤转化，因为转录-复制冲突是主要的 常见脆性部位不稳定性的根源。