Functional Characterization of the Mammalian MOF Gene Product

哺乳动物 MOF 基因产物的功能表征

• 批准号: 7652536
• 负责人: Tej K Pandita
• 金额: $ 0.15万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2010-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7652536
• 关键词: Acetylation; Address; Appearance; Biochemical; Biological Assay; Cell Cycle; Cell Survival; Cells; Chromatin; Chromatin Structure; Chromosome abnormality; Chromosomes; Clinical; DNA; DNA Damage; DNA Repair; Defect; Development; Dominant-Negative Mutation; Drosophila genus; Embryo; Exposure to; Fibroblasts; Frequencies; Genes; Genome Stability; Genomic Instability; Goals; Histone H4; Human; In Vitro; Ionizing radiation; Kinetics; Knockout Mice; Link; Lysine; Malignant Neoplasms; Mammalian Cell; Measures; Metaphase; Mus; Mutant Strains Mice; Neoplastic Cell Transformation; Oncogenic; Orthologous Gene; Participant; Phase; Phenotype; Predisposition; Proteins; Radiation therapy; Role; Signal Transduction Pathway; Small Interfering RNA; System; Testing; Tissues; Tumor Tissue; Work; ataxia telangiectasia mutated protein; base; cell killing; histone acetyltransferase; homologous recombination; improved; in vivo; insight; irradiation; male; metaplastic cell transformation; recombinational repair; research study; response; telomere; tumor; tumorigenesis

DESCRIPTION (provided by applicant): Understanding the role of chromatin modifying factors in response to ionizing radiation (IR) will provide invaluable insights into questions of both how cancers start and how to cure cancers. The ATM (ataxia-telangiectasia mutated) protein is a major participant in .all cellular responses to IR. We have been studying the role of ATM in DNA damage repair, telomere chromatin structure and oncogenic transformation. Cells deficient in ATM have defects in DNA repair, display altered telomere chromatin structure and have a higher frequency of spontaneous as well as IR-induced oncogenic transformation. Recently, we identified a chromatin-modifying factor "hMOF", the human ortholog of the Drosophila MOF gene (Males absent On the First) which interacts with ATM. hMOF has histone acetyltransferase (HAT) activity. Cellular exposure to IR enhances hMOF-dependent acetylation of its target substrate, lysine 16 of histone H4 (H4- K16), independent of ATM function. Inactivation of hMOF results in abrogation of ATM function. Based on the facts that hMOF is involved in ATM function, expression of MOF fragment enhances oncogenic transformation in vitro and that tumors show loss of H4-K16 acetylation (H4-K16Ac), we hypothesize that hMOF is involved in tumorigenesis. In the proposed work, we will determine the link between MOF and tumorigenesis by the functional characterization of mouse Mof (mMof) in a murine cell system and pathobiology of mMof haploinsufficient and mMof conditional knockout mice. The in vitro studies will determine Atm dependent and independent mMof functions in response to IR for cell killing, DNA damage repair and oncogenic transformation. The impact of the loss of H4-K16Ac on the predisposition of mouse tumor development will be determined in mMof haploinsufficiency or mMof conditional knockout mice. Experiments described in this proposal will investigate the functional links among mMof, H4-K16Ac and spontaneous as well as IR-induced tumor formation. These studies will improve our understanding of the role of mMof in the IR response and tumorigenesis. Ultimately, understanding the basis for biochemical differences in chromatin structure between normal and tumor tissue could provide strategies for modifying the response to IR that could be useful in clinical radiation therapy.

描述（由申请人提供）：了解染色质修饰因子在电离辐射（IR）反应中的作用将为癌症如何开始和如何治愈癌症的问题提供宝贵的见解。ATM（ataxia-telangiectasia mutated）蛋白是所有细胞对IR反应的主要参与者，我们一直在研究ATM在DNA损伤修复、端粒染色质结构和致癌转化中的作用。ATM缺陷的细胞在DNA修复方面有缺陷，显示端粒染色质结构改变，并且具有较高的自发性以及IR诱导的致癌转化频率。最近，我们发现了一个染色质修饰因子“hMOF”，它是果蝇MOF基因（雄性在第一个缺失）的人类直系同源物，它与ATM相互作用。hMOF具有组蛋白乙酰转移酶（HAT）活性。细胞暴露于IR增强了其靶底物（组蛋白H4的赖氨酸16（H4- K16））的hMOF依赖性乙酰化，与ATM功能无关。hMOF的失活导致ATM功能的废除。基于hMOF参与ATM功能，MOF片段的表达增强体外致癌转化以及肿瘤显示H4-K16乙酰化（H4-K16 Ac）的缺失的事实，我们假设hMOF参与肿瘤的发生。在拟议的工作中，我们将确定MOF和肿瘤发生之间的联系，通过小鼠Mof（mMof）在小鼠细胞系统中的功能表征和mMof单倍不足和mMof条件性基因敲除小鼠的病理生物学。体外研究将确定Atm依赖性和非依赖性mMof功能，以响应IR，用于细胞杀伤、DNA损伤修复和致癌转化。将在mMof单倍不足或mMof条件性敲除小鼠中确定H4-K16 Ac缺失对小鼠肿瘤发展倾向的影响。本提案中描述的实验将研究mMof、H4-K16 Ac和自发以及IR诱导的肿瘤形成之间的功能联系。这些研究将提高我们对mMof在IR反应和肿瘤发生中的作用的理解。最终，了解正常组织和肿瘤组织之间染色质结构的生化差异的基础可以提供修改对IR的反应的策略，这可能在临床放射治疗中有用。