Roles of Spartan in translesion synthesis and UV-induced carcinogenesis

Spartan 在跨损伤合成和紫外线诱发的致癌作用中的作用

基本信息

批准号：
8890426
负责人：
GARGI GHOSAL
金额：
$ 13.39万
依托单位：
UNIVERSITY OF NEBRASKA MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-08-01 至 2019-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8890426
关键词：
Binding Biological Assay Biological Process Butane Bypass CRISPR/Cas technology Cell Proliferation Cell Survival Cells Chromatin Cutaneous Melanoma DNA DNA Adducts DNA Damage DNA Repair Pathway DNA biosynthesis DNA lesion DNA replication fork DNA-Directed DNA Polymerase Databases Development Epithelium Fiber Genes Genomic Instability Health In Vitro Knock-out Knockout Mice Lead Left Lesion Malignant Neoplasms Mediating Melanoma Cell Metalloproteases Metastatic Melanoma Modeling Mono-S Mus Mutagenesis Mutation Pathway interactions Peptide Hydrolases Pharmaceutical Preparations Physiological Play Polymerase Process Proteins Proteolysis Pyrimidine Dimers Resistance Role Site Skin Skin Cancer Skin Carcinogenesis Sun Exposure System The Cancer Genome Atlas Time UV carcinogenesis UV induced UV induced DNA damage Ubiquitination Ultraviolet Rays Ultraviolet Therapy base cancer cell cancer therapy chemotherapeutic agent in vivo insight melanocyte melanoma mutant neoplastic cell overexpression prevent reconstitution repaired response targeted cancer therapy tumorigenesis ultraviolet damage

项目摘要

DESCRIPTION (provided by applicant): This study aims at understanding the roles of Spartan in translesion synthesis (TLS) and UV-induced carcinogenesis. TLS is a post-replication repair pathway, which mediates bypass of bulky DNA lesions that stall replication forks, during DNA replication. Bypass of DNA lesions is mediated by specialized low-fidelity TLS polymerase that can replicate over distortions or bulky DNA adducts efficiently, leaving behind the lesion to be repaired at a later time point. The critical step in TLS is the switch of the replicative polymeras with TLS polymerase, which is proposed to be mediated by RAD18-dependent ubiquitination of PCNA (ub-PCNA). However, the exact mechanism is not clear. We identified Spartan as a key regulator of TLS. Depletion of Spartan renders cells sensitive to UV damage, results in a decrease in PCNA mono-ubiquitination, which is accompanied by a reduction of RAD18 chromatin association and RAD18 localization to DNA damage sites. Interestingly, Spartan binds to replicative DNA polymerase under normal conditions, but preferentially associates with TLS polymerase POLH upon UV damage. Based on our observations, we proposed that Spartan is a key regulator of TLS, required to stabilize RAD18 and ub-PCNA at the sites of DNA damage and may directly regulate the switch from replicative polymerase to TLS polymerase during TLS. However, how Spartan mediates its regulatory functions and the switch between the DNA polymerases during TLS is not known and will be the focus of this study. The specific aims for this proposal are: Aim 1) Determine the function of Spartan in TLS upon UV damage; Aim 2) Determine the roles of Spartan mediated TLS in UV-induced carcinogenesis and resistance to chemotherapeutic agents; Aim 3) Determine the in vivo physiological functions of Spartan. This proposed study will not only provide useful insights into the regulatory mechanism of TLS process, but also, will explore the potential of targeting Spartan for cancer therapy.

描述（由申请人提供）：本研究旨在了解 Spartan 在跨损伤合成 (TLS) 和紫外线诱导的致癌作用中的作用，TLS 是一种复制后修复途径，可在复制过程中介导绕过大量 DNA 损伤，从而阻止复制叉。 DNA 复制。DNA 损伤的绕过是由专门的低保真 TLS 聚合酶介导的，该酶可以有效地复制扭曲或庞大的 DNA 加合物，从而留下待修复的损伤。 TLS 的关键步骤是复制聚合酶与 TLS 聚合酶的转换，这被认为是由 RAD18 依赖性 PCNA 泛素化 (ub-PCNA) 介导的，但我们尚不清楚 Spartan 是一个关键调节因子。 Spartan 的消耗使细胞对紫外线损伤敏感，导致 PCNA 单泛素化减少，同时伴随着 RAD18 染色质关联的减少和RAD18 定位于 DNA 损伤位点。在正常条件下，Spartan 与复制 DNA 聚合酶结合，但在紫外线损伤时优先与 TLS 聚合酶 POLH 结合，根据我们的观察，我们认为 Spartan 是稳定 RAD18 和 ub 所必需的。 -PCNA 在 DNA 损伤位点，可能直接调节 TLS 期间从复制聚合酶到 TLS 聚合酶的转换，但是，Spartan 如何介导其调节功能和转换。 TLS 过程中 DNA 聚合酶之间的相互作用尚不清楚，这将是本研究的重点。目标 1) 确定 Spartan 在 TLS 中对紫外线损伤的作用；目标 2) 确定 Spartan 介导的 TLS 的作用。目的 3) 确定 Spartan 的体内生理功能，这项研究不仅为了解 Spartan 的调节机制提供了有用的见解。 TLS 过程还将探索针对 Spartan 进行癌症治疗的潜力。