| 研究実績の概要 |
During the fiscal year 2019:
1. Role of TOP2 in chromosomal organization
1.1. Analysis of genome organization in the absence of TOP2. I generated cell lines that are deficient for TOP2 that I will use to characterize the role of TOP2 in genome organization. 1.3. Identification of TOP2β interactions with cohesin components by co-immunoprecipitation. I found by co-immunoprecipitation what cohesin components interact with TOP2β and how this interaction is mediated.
2. Role of TOP2 promoting oncogenic translocations
2.1. Determine the kinetics of generation and repair of TOP2cc. With the modifications in the method END-seq, I was able study how TOP2cc are processed in TOP2-free DSBs, determine the kinetics across the genome and identify factors that modulate this process. I found that although TOP2 binding and cleavage complex (TOP2cc) formation is dependent on cohesin, the conversion of TOP2cc into protein-free DSBs is facilitated by transcription. 2.2 Evaluate of the mechanisms of processing and repair of TOP2cc. I found that transcription is mediating the conversion TOP2cc into protein-free DSBs by proteasomal degradation and TDP2 phosphodiesterase activity. 2.3 Investigate how etoposide-dependent DSBs can lead to chromosomal translocations. I found that transcription promotes chromosomal translocation at TOP2cc mainly by accelerating the conversion of TOP2ccs to DSBs, but has less of an impact on stimulating fusions once DNA ends are protein free.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
During the fiscal year 2019:
1. Role of TOP2 in chromosomal organization. I have made significative advances in this aim by accomplishing the points originally proposed.
2. Role of TOP2 promoting oncogenic translocations. I have made extensive advances in this aim. My results revealed the importance of transcription and chromosomal architecture on the initiation, processing, and repair of Topoisomerase2 breaks. This work was published in the fiscal year 2019: Canela A, Maman Y, Huang SN, Wutz G, Tang W, Zagnoli-Vieira G, Callen E, Wong N, Day A, Peters JM, Caldecott KW, Pommier Y, Nussenzweig A. Topoisomerase II-Induced Chromosome Breakage and Translocation Is Determined by Chromosome Architecture and Transcriptional Activity. Mol Cell 75, 252-266 (2019)
10.1016/j.molcel.2019.04.030
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