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: 7162080
• 负责人: JoAnn Sekiguchi
• 金额: $ 28.51万
• 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 2009-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7162080
• 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; 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（由申请人提供）：在针对外来抗原的免疫反应的初始阶段，B和T细胞表面表达的大量受体识别并结合无数的外来分子。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，在该过程中各个 V、D 和 J 基因片段重新排列。 V(D)J 重组需要两种类型的活动：淋巴特异性因子，例如重组激活基因 1 和 2 (RAG1/2)，以及普遍表达的非同源末端连接 (NHEJ) DNA 修复因子，例如 Artemis。众所周知，Artemis 的突变会导致人类严重的与细胞放射敏感性相关的联合免疫缺陷综合征 (RS-SCID)。最近的证据表明，Artemis 的亚等位基因突变也可能导致人类患者罹患淋巴瘤。 Artemis 是一种 76 kDa 的蛋白质，具有单链 5' 至 3' 核酸外切酶活性，并在与 DNA 依赖性蛋白激酶催化亚基 (DNA-PKcs) 相互作用并被其磷酸化后获得核酸内切活性。除了在 V(D)J 重组中发挥作用外，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 Artemis 的多种功能是否需要外切和内切核酸酶活性或 DNA-PKcs 的调节，也不清楚在人类患者中发现的 Artemis 突变对其内在生化活性有何影响。因此，本提案中描述的具体目标的目标是使用组合的生化、细胞和遗传学方法来进一步阐明 Artemis 的催化功能和体内作用。这些研究将使人们更清楚地了解 Artemis 在 DNA 修复过程中的功能，并深入了解人类患者免疫系统缺陷和淋巴恶性肿瘤易感性的分子机制。