ABERRANT DNA SYNTHESIS IN DIVIDING AND NONDIVIDING CELLS

分裂细胞和非分裂细胞中的异常 DNA 合成

• 批准号: 6295384
• 负责人: MYRON GOODMAN
• 金额: $ 33.2万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2000-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6295384
• 关键词: DNA damage; DNA directed DNA polymerase; DNA repair; DNA replication; DNA replication origin; Drosophilidae; Escherichia coli; apoptosis; brain cell; cell cycle; frameshift mutation; gel filtration chromatography; protein purification; site directed mutagenesis

This proposal is focused on elucidating the biochemical basis of aberrant DNA synthesis in the dividing and non-dividing cells in eucaryotic organisms, with strong emphasis placed on the study of brain cells. Somatic mutations are an important source of human disease. In addition to mutations occurring in dividing cell populations, there is accumulating evidence that mutations are also occurring in non-dividing cells, both procaryotic and eucaryotic. Genomic DNA is constantly undergoing potentially deleterious modifications in the form of slippage expansions and deletions, deaminations, loss of bases, UV damage, and chemically-induced adduct formations, to cite just a few examples. All living organisms have evolved powerful, highly selective biochemical pathways to repair damaged DNA. However, these repair processes are not perfect, and indeed they cannot be, because living organisms must be able to mutate in order to adapt to changing local environments and to evolve. Our proposal addresses questions of how eucaryotic cells copy DNA containing unrepaired lesions. There is recent evidence for an alternative pathway to apoptosis (programmed cell death), involving "error-prone" eucaryotic proteins required to alleviate blocked DNA synthesis at lesion sites and to catalyze lesion bypass leading to mutations. Our specific aims re to identify, purify and characterize eucaryotic lesion bypass proteins.

该提案的重点是阐明其生化基础 分裂细胞和非分裂细胞中 DNA 合成异常 真核生物，重点研究大脑 细胞。体细胞突变是人类疾病的重要来源。在 除了分裂细胞群中发生的突变外，还有 越来越多的证据表明突变也发生在非分裂细胞中 细胞，包括原核细胞和真核细胞。基因组DNA不断 以滑移的形式进行潜在有害的修改 扩展和删除、脱氨基、碱基损失、紫外线损伤和 化学诱导的加合物形成，仅举几个例子。全部 生物体已经进化出强大的、高度选择性的生化物质 修复受损 DNA 的途径。然而，这些修复过程并不 完美，事实上它们不可能，因为生物体必须是完美的 能够变异以适应不断变化的当地环境 发展。我们的提案解决了真核细胞如何复制的问题 含有未修复损伤的 DNA。最近有证据表明 细胞凋亡的替代途径（程序性细胞死亡），涉及 缓解 DNA 阻塞所需的“易错”真核蛋白 在病变部位合成并催化病变旁路导致 突变。我们的具体目标是识别、纯化和表征 真核病变旁路蛋白。