Roles of the Artemis nuclease in DNA repair and disease

Artemis 核酸酶在 DNA 修复和疾病中的作用

• 批准号: 7555918
• 负责人: JoAnn Sekiguchi
• 金额: $ 27.97万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-01-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7555918
• 关键词: Active Sites; Antigen Receptors; Antigens; Binding; Biochemical; Biological; Biological Process; Catalysis; Catalytic Domain; Cellular Assay; Chromosome abnormality; DNA; DNA Damage; DNA Double Strand Break; DNA Repair; DNA Structure; DNA-dependent protein kinase; Defect; Development; Disease; Disease Outcome; Double Strand Break Repair; Enzymes; Exhibits; Exonuclease; Funding; Gene Targeting; Genes; Genetic; Goals; Human; Hypersensitivity; Immune response; Immune system; Immunologic Deficiency Syndromes; Individual; J segment gene; Lactamase; Lead; Lymphocyte; Lymphoid; Lymphoma; Malignant lymphoid neoplasm; Molecular; Mus; Mutate; Mutation; Nonhomologous DNA End Joining; Patients; Phenotype; Phosphorylation; Predisposition; Principal Investigator; Process; Protein Family; Protein-Serine-Threonine Kinases; Proteins; RAG1 gene; Radiation Tolerance; Regulation; Research Personnel; Role; Sequence Homology; Severe Combined Immunodeficiency; Site-Directed Mutagenesis; Staging; Surface; T-Lymphocyte; Translations; V(D)J Recombination; artemis; base; endonuclease; human disease; in vivo; insight; member; mutant; nuclease; premature; programs; receptor; spleen exonuclease; tumorigenesis

DESCRIPTION (provided by applicant): During the initial stages of the immune response against foreign antigens, a vast array of receptors expressed on the surface of B and T cells recognize and bind the myriad of foreign molecules. Diversity amongst the genes encoding the recognition regions of antigen receptors is generated through V(D)J recombination, a process in which individual V, D, and J gene segments are rearranged. Two types of activities are required for V(D)J recombination; lymphoid-specific factors, such as recombination activating genes 1 and 2 (RAG1/2), and the ubiquitously expressed non-homologous end-joining (NHEJ) DNA repair factors, such as Artemis. Mutations in Artemis are known to cause a human severe combined immunodeficiency syndrome associated with cellular radiosensitivity (RS-SCID). Recent evidence suggests that hypomorphic mutations in Artemis may also predispose to lymphoma in human patients. Artemis, a 76 kDa protein, possesses single strand 5' to 3' exonuclease activity and acquires endonucleolytic activity upon interaction with and phosphorylation by the DNA-dependent protein kinase catalytic subunit (DNA-PKcs). In addition to its role in V(D)J recombination, Artemis is also required for general DNA double strand break repair (DSB) and suppressing chromosomal aberrations, including translocations and telomeric fusions. It is not yet known whether both exo- and endonucleolytic activities or regulation by DNA-PKcs are required for each of the multiple functions of Artemis, nor is it clear what impact the Artemis mutations found in human patients have on its intrinsic biochemical activities. Thus, the goals of the specific aims described in this proposal are to use combined biochemical, cellular and genetic approaches to further elucidate the catalytic repertoire and in vivo roles of Artemis. These studies will provide a more clear understanding of the functions of Artemis in DNA repair processes and insights into the molecular mechanisms underlying immune system defects and predisposition to lymphoid malignancies in human patients.

描述（申请人提供）：在免疫反应针对异物抗原的初始阶段，在B和T细胞表面表达的大量受体识别并结合了众多外国分子。编码抗原受体识别区域的基因之间的多样性是通过V（d）J重组产生的，即单个V，D和J基因段的重组。 V（d）重组需要两种类型的活动；淋巴特异性因素，例如重组激活基因1和2（RAG1/2），以及无处不在表达的非同源末端连接（NHEJ）DNA修复因子，例如artemis。众所周知，artemis中的突变会引起与细胞辐射敏感性相关的人类严重的联合免疫缺陷综合征（RS-SCID）。最近的证据表明，阿耳emi虫的肌肉突变也可能倾向于人类患者的淋巴瘤。 Artemis是一种76 kDa蛋白，具有5'至3'外切核酸酶活性的单链，并在与DNA依赖性蛋白激酶催化亚基（DNA-PKC）相互作用后获得核液溶性活性。除了其在V（d）J重组中的作用外，Artemis还需要进行一般DNA双链断裂修复（DSB）和抑制染色体畸变，包括易位和端粒融合。目前尚不清楚阿耳emis虫的每个多种功能中的每一个都需要核和内核解活性或DNA-PKC的调节，也不清楚人类患者在人类患者中发现的对其内在生化活性的影响。因此，本提案中描述的特定目的的目标是使用合并的生化，细胞和遗传方法进一步阐明催化曲目和体内Artemis的作用。这些研究将对Artemis在DNA修复过程中的功能以及对免疫系统缺陷的分子机制的见解以及对人类患者淋巴恶性肿瘤的易感性提供更清晰的了解。