The Function of Werner Syndrome Protein

维尔纳综合征蛋白的功能

• 批准号: 7964021
• 负责人: Vilhelm Bohr
• 金额: $ 32.27万
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7964021
• 关键词: ATP phosphohydrolase; Acceleration; Acetylation; Affect; Age; Aging; Aging-Related Process; Base Excision Repairs; Biochemical; Biological; Biological Assay; Cataract; Cell Communication; Cell Cycle Regulation; Cells; Characteristics; Chromosomes; Complex; DNA; DNA Damage; DNA Repair; DNA Repair Pathway; DNA Sequence Rearrangement; DNA Structure; Data; Defect; Diabetes Mellitus; Disease; Exonuclease; Family; Genes; Genetic Recombination; Genome Stability; Genomic Instability; Gray unit of radiation dose; Hair; Homologous Gene; Human; In Vitro; Individual; Lead; Lesion; Life; Light; Maintenance; Metabolism; Mutate; Nematoda; Normal Cell; Organism; Osteoporosis; Pathway interactions; Patients; Phosphodiesterase I; Population; Post-Translational Protein Processing; Premature aging syndrome; Process; Proteins; Regulation; Role; Signal Transduction; Signs and Symptoms; Skin Wrinkling; Staging; TERF1 gene; WRN gene; Werner Syndrome; Work; base; early onset; experience; helicase; human WRN protein; in vivo; insertion/deletion mutation; insight; normal aging; senescence; telomere; triple helix

Werner's syndrome (WS) is a homozygous recessive disease characterized by early onset of many characteristics of normal aging, such as wrinkling of the skin, graying of the hair, cataracts, diabetes, and osteoporosis. Because of the acceleration of aging in WS, the study of this disease will hopefully shed light on the degenerative processes that occur in normal aging. Cells from WS patients grow more slowly and senescence at an earlier population doubling than age-matched normal cells, possibly because these cells appear to lose the telomeric ends of their chromosomes at an accelerated rate. In general, WS cells have a high level of genomic instability, with increased amounts of DNA deletions, insertions, and rearrangements. These effects could potentially be the result of defects in DNA repair, replication, and/or recombination, although the actual biochemical defect remains unknown. The gene that is defective in WS, the WRN gene, has been identified and characterized. We have made purified WRN protein for use in a number of basic and complex biochemical assays. We are pursuing several avenues to identify and characterize the biochemical defect in WS cells. WRN protein has helicase activity and will unwind small and large DNA duplex constructs. It will also unwind unusual DNA structures such as triple helices and DNA forks. We are comparing the Werner helicase activity to that of another helicases in the family of RecQ helicases that are all involved in the maintenace of genome stability. WRNp has another enzymatic activity, a 3-5' exonuclease function. We are searching for pathways in which WRN participates and have discovered a number of new functional and physical protein interactions with Werner protein. Our data strongly suggest that WRN is involved in two of the major DNA repair pathways: base excision repair and recombination. This conclusion is supported by biochemical studies of protein functional interaction and by cell biological data. Further, our observations and results from other work suggest that a major function of WRN is at the telomere end. WRN interacts with key telomeric proteins such as TRF1 and 2 and POT1. These observations of functional protein interactions corroborated by cell biological observations suggest that WRN protein is involved in DNA repair processes and maintenance at the telomere end. WRN is also involved in the DNA repair process. Specifically, we find in vitro and in vivo evidence for a role of WRN in the DNA repair of oxidative DNA base lesions and in the DNA repair of double strand breaks. Further, post-translational modification of WRN protein can changes its activities in the DNA repair process and thus might be involved in the regulation of these processes. For example, the acetylation of WRN enhances its activities in DNA repair and is likely a significant step in DNA damage signaling. We have also characterized the function of the homolog of WRNp found in the simple organism, the nematode. Interestingly, the nematode WRN protein has similar biochemical characteristics to the human WRNp.

Werner's综合征（WS）是一种纯合性隐性疾病，其特征是正常衰老的许多特征早期发作，例如皮肤皱纹，头发的灰色，白内障，糖尿病和骨质疏松症。由于WS中的衰老加速，该疾病的研究将有望阐明正常衰老中发生的退化过程。来自WS患者的细胞生长较慢，并且在较早的人群中衰老比年龄匹配的正常细胞增加一倍，这可能是因为这些细胞似乎以加速速率失去了其染色体的端粒末端。通常，WS细胞具有高水平的基因组不稳定性，DNA缺失，插入和重排的量增加。尽管实际的生化缺陷仍然未知，但这些影响可能是DNA修复，复制和/或重组缺陷的结果。 WS中有缺陷的WRN基因的基因已被鉴定和表征。我们已将纯化的WRN蛋白用于许多基本和复杂的生化测定法。我们正在追求几种途径，以识别和表征WS细胞中生化缺陷。 WRN蛋白具有解旋酶活性，并将放松大小的DNA双链体构建体。它还将放松异常的DNA结构，例如三螺旋和DNA叉。我们将Werner解旋酶活性与RECQ解旋酶家族中的其他解旋酶的活性进行比较，这些酶都参与了基因组稳定性的维持层。 WRNP具有另一种酶促活性，是3-5'外丝酶功能。我们正在寻找WRN参与的途径，并发现了许多与Werner蛋白质的新功能和物理蛋白相互作用。 我们的数据强烈表明WRN参与了两个主要的DNA修复途径：基础切除修复和重组。 蛋白质功能相互作用和细胞生物学数据的生化研究支持了这一结论。 此外，我们的其他工作的观察结果和结果表明，WRN的主要功能在端粒端。 WRN与关键的端粒蛋白（例如TRF1和2和POT1）相互作用。 通过细胞生物学观察结果证实的功能蛋白相互作用的这些观察结果表明，WRN蛋白参与了DNA修复过程和端粒端的维持。 WRN也参与了DNA修复过程。具体而言，我们发现在体外和体内证据证明了WR在氧化DNA碱病变的DNA修复以及双链断裂的DNA修复中的作用。此外，WRN蛋白的翻译后修饰可以改变其在DNA修复过程中的活性，因此可能与这些过程的调节有关。例如，WRN的乙酰化增强了其在DNA修复中的活性，并且可能是DNA损伤信号传导的重要一步。我们还表征了在简单生物体的线虫中发现的WRNP同源物的功能。 有趣的是，线虫WRN蛋白具有与人WRNP相似的生化特征。