GENOMIC INSTABILITY

基因组不稳定

• 批准号: 6160484
• 负责人: V A BOHR
• 金额: --
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6160484
• 关键词: DNA damage; DNA repair; DNA replication; aging; gene expression; gene interaction; genome; guanine nucleotide binding protein; human tissue; neoplasm /cancer genetics; telomere; tissue /cell culture; tumor suppressor genes

Summary of work: We have studied the role of the aging gene, p21 on the DNA repair process. Two components of the p21 protein were purified, the C- and B terminals. Both p21 and its C-terminal region inhibit DNA repair synthesis activity using in vitro cell extracts, while the N-terminal region does not. The addition of p21 antibodies alleviates this inhibition, indicating the effect is specific to p21. Addition of excess PCNA also alleviates this inhibition, suggesting that the inhibition of repair activity by p21 (and its C-terminal fragment) is mediated through its interaction with PCNA. This inhibitory effect of p21 on the DNA repair process is also demonstrated in vivo in intact cells by the electroporetion of the p21 protein. The SCID mouse is severely immunodeficient and it has been shown to be deficient in the repair of DNA double strand breaks. We demonstrate that fibroblasts from this mouse is also deficient in a component of nucleotide excision repair, transcription coupled DNA repair. The role of this form of DNA repair in immunodeficiency is being explored.

工作总结：我们研究了衰老基因p21对衰老的作用 DNA修复过程。 p21蛋白的两个成分被纯化， C 和 B 端子。 p21 及其 C 末端区域均抑制 DNA 使用体外细胞提取物修复合成活性，而 N 末端区域没有。 添加 p21 抗体可以缓解 这种抑制表明该效应是 p21 特有的。 添加 过量的 PCNA 也减轻了这种抑制作用，表明 p21（及其 C 端片段）对修复活性的抑制是 通过与 PCNA 的相互作用介导。 p21的这种抑制作用 DNA 修复过程的影响也在完整细胞的体内得到了证明 p21 蛋白的电穿孔。 SCID 小鼠具有严重的免疫缺陷，并且已被证明 DNA双链断裂修复缺陷。 我们证明 该小鼠的成纤维细胞也缺乏核苷酸成分 切除修复、转录耦合DNA修复。 这个表格的作用 DNA 修复在免疫缺陷中的作用正在探索中。