核糖体蛋白S27L调节DNA修复的分子机制研究

DNA repair is crucial to cellular and organismal function, and defects in the process have been implicated in tumorigenesis. It was recently found that several ribosomal proteins regulate DNA repair as a kind of extraribosomal functions. Ribosomal protein S27-like (RPS27L) was proved to maintain genomic stability in vivo as a tumor suppressor, and elevated RPS27L may improve the prognoses of certain colorectal cancer patients by enhancing the DNA repair capacity of their colonic cells. Our preliminary data showed that 1) knockdown of RPS27L sensitizes cells and mice to irradiation; 2) RPS27L silencing remarkably inhibits non-homologous end joining (NHEJ) activity and 3) RPS27L may be involved in regulation of multiple DNA repair pathways via interacting with several DNA repair proteins. However the molecular mechanism of DNA repair regulated by RPS27L remains elusive. This proposal aims at confirming the regulatory role of RPS27L in multiple DNA repair pathways, and elucidating the molecular mechanism with approaches of molecular biology and cell biology. We expect that the proposed research will offer experimental and theoretical basis to investigate the role of ribosomal proteins in genomic stability maintenance and tumorigenesis.

DNA修复对于细胞和生物体的正常功能至关重要，因而修复过程中的缺陷与癌症发生紧密相关。近几年研究发现多个核糖体蛋白具有参与DNA修复调控的核糖体外功能，其中核糖体蛋白RPS27L在体内被证实具有维持基因组稳定性的抑癌作用，其调节DNA修复的能力可能与高表达RPS27L结肠癌患者表现出的更长生存期密切相关。我们的预实验结果显示，敲除RPS27L能增加细胞和小鼠对辐射的敏感性，RPS27L沉默显著抑制细胞内非同源末端连接（NHEJ）通路修复DNA损伤的活性，且RPS27L可能通过与一些DNA修复蛋白的相互作用参与多条DNA修复通路的调控。但RPS27L调控DNA修复的分子机理还非常不清楚。本项目将运用分子生物学和细胞生物学手段明确RPS27L在多条DNA修复通路中的具体调控作用，阐明其调控的分子机制，为研究核糖体蛋白在维持基因组稳定性和癌症发生中的作用提供实验基础和理论依据。

DNA修复对于细胞和生物体的正常功能至关重要，因而修复过程中的缺陷与癌症发生紧密相关。近几年研究发现多个核糖体蛋白具有参与DNA修复调控的核糖体外功能，其中核糖体蛋白RPS27L在体内被证实具有维持基因组稳定性的抑癌作用，其调节DNA修复的能力可能与高表达RPS27L结肠癌患者表现出的更长生存期密切相关。我们的实验结果显示，敲除RPS27L能增加细胞和小鼠对辐射的敏感性，RPS27L与范可尼贫血（FA）蛋白存在相互作用，RPS27L沉默显著降低细胞内FA蛋白水平以及交联损伤（ICL）修复的活性。本项目运用分子生物学和细胞生物学手段明确RPS27L在DNA修复通路（FA）中的具体调控作用，阐明其调控的分子机制，为研究核糖体蛋白在维持基因组稳定性和癌症发生中的作用提供实验基础和理论依据。