The MluI Cell Cycle Box (MCB) Motifs, but Not Damage-Responsive Elements (DREs), Are Responsible for the Transcriptional Induction of the rhp51(+) Gene in Response to DNA Replication Stress

作者：Sartagul, Wugangerile; Zhou, Xin^*; Yamada, Yuki; Ma, Ning; Tanaka, Katsunori; Furuyashiki, Tomoyuki; Ma, Yan

来源：PLos One, 2014, 9(11): e111936.

DOI：10.1371/journal.pone.0111936

• FISSION YEAST
• G1-SPECIFIC TRANSCRIPTION
• SCHIZOSACCHAROMYCES-POMBE
• ACTIVATED KINASE
• S PHASE
• CHECKPOINT
• PHOSPHORYLATION
• ASSOCIATION
• INHIBITOR
• PATHWAYS

DNA replication stress induces the transcriptional activation of rhp51(+), a fission yeast recA homolog required for repair of DNA double strand breaks. However, the mechanism by which DNA replication stress activates rhp51(+) transcription is not understood. The promoter region of rhp51(+) contains two damage-responsive elements (DREs) and two MluI cell cycle box (MCB) motifs. Using luciferase reporter assays, we examined the role of these elements in rhp51(+) transcription. The fulllength rhp51(+) promoter and a promoter fragment containing MCB motifs only, but not a fragment containing DREs, mediated transcriptional activation upon DNA replication stress. Removal of the MCB motifs from the rhp51(+) promoter abolished the induction of rhp51(+) transcription by DNA replication stress. Consistent with a role for MCB motifs in rhp51(+) transcription activation, deletion of the MBF (MCB-binding factor) co-repressors Nrm1 and Yox1 precluded rhp51(+) transcriptional induction in response to DNA replication stress. Using cells deficient in checkpoint signaling molecules, we found that the Rad3-Cds1/Chk1 pathway partially mediated rhp51(+) transcription in response to DNA replication stress, suggesting the involvement of unidentified checkpoint signaling pathways. Because MBF is critical for G1/S transcription, we examined how the cell cycle affected rhp51(+) transcription. The transcription of rhp51(+) and cdc18(+), an MBF-dependent G1/S gene, peaked simultaneously in synchronized cdc25-22 cells. Furthermore, DNA replication stress maintained transcription of rhp51(+) similarly to cdc18(+). Collectively, these results suggest that MBF and its regulators mediate rhp51(+) transcription in response to DNA replication stress, and underlie rhp51(+) transcription at the G1/S transition.

• 出版日期2014-11-5
• 单位锦州医科大学