期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2014
卷号：111
期号：44
页码：15816-15820
DOI：10.1073/pnas.1415011111
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceTyrosyl-DNA phosphodiesterase 1 (TDP1) is a novel repair enzyme that removes 3'-DNA blocking groups generated by topoisomerase cleavage complexes, oxidative DNA lesions, and base alkylation during normal transcription and replication, and by widely used anticancer drugs that induce DNA strand breaks including topoisomerase inhibitors (topotecan, irinotecan, etoposide), bleomycin, and alkylating agents (temozolomide). This report demonstrates that the Drosophila gene glaikit (gkt) is the ortholog of TDP1. It also demonstrates the critical importance of TDP1 (gkt) for normal neurological development and lifespan, potentially linking TDP1 and mitochondria to neurodegenerative diseases. Tyrosyl-DNA phosphodiesterase (TDP1) is a phylogenetically conserved enzyme critical for the removal of blocking lesions at the 3' ends of DNA or RNA. This study analyzes the Drosophila TDP1 gene ortholog glaikit (gkt) and its possible role(s) in the repair of endogenous DNA lesions and neuroprotection. To do so, we studied a homozygous PiggyBac insertion (c03958) that disrupts the 5' UTR of gkt. Protein extracts of c03958 flies were defective in hydrolyzing 3'-DNA-tyrosyl residues, demonstrating that gkt is the Drosophila TDP1. Although the mutant is generally healthy and fertile, females exhibit reduced lifespan and diminished climbing ability. This phenotype was rescued by neuronal expression of TDP1. In addition, when c03958 larvae were exposed to bleomycin, an agent that produces oxidative DNA damage, or topoisomerase I-targeted drugs (camptothecin and a noncamptothecin indenoisoquinoline derivative, LMP-776), survivors displayed rough eye patches, which were rescued by neuronal expression of TDP1. Our study establishes that gkt is the Drosophila TDP1 gene, and that it is critical for neuroprotection, normal longevity, and repair of damaged DNA.
关键词：aging ; neuroscience ; DNA repair ; topoisomerase ; fly
