Omidi Katayoun, Jessulat Matthew, Hooshyar Mohsen, Burnside Daniel, Schoenrock Andrew, Kazmirchuk Tom, Hajikarimlou Maryam, Daniel Mary, Moteshareie Houman, Bhojoo Urvi, Sanders Megan, Ramotar Dindial, Dehne Frank, Samanfar Bahram, Babu Mohan, Golshani Ashkan
Department of Biology, Carleton University, Ottawa, Ontario, Canada; Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Ontario, Canada.
Department of Biochemistry, Research and Innovation Centre, University of Regina, Regina, Saskatchewan, Canada.
Gene. 2018 Jan 10;639:128-136. doi: 10.1016/j.gene.2017.10.003. Epub 2017 Oct 5.
Non-Homologous End Joining (NHEJ) is a highly conserved pathway that repairs Double-Strand Breaks (DSBs) within DNA. Here we show that the deletion of yeast uncharacterized ORF HUR1, Hydroxyurea Resistance1 affects the efficiency of NHEJ. Our findings are supported by Protein-Protein Interaction (PPI), genetic interaction and drug sensitivity analyses. To assess the activity of HUR1 in DSB repair, we deleted its non-overlapping region with PMR1, referred to as HUR1-A. We observed that similar to deletion of TPK1 and NEJ1, and unlike YKU70 (important for NHEJ of DNA with overhang and not blunt end), deletion of HUR1-A reduced the efficiency of NHEJ in both overhang and blunt end plasmid repair assays. Similarly, a chromosomal repair assay showed a reduction for repair efficiency when HUR1-A was deleted. In agreement with a functional connection for Hur1p with Tpk1p and NEJ1p, double mutant strains Δhur1-A/Δtpk1, and Δhur1-A/Δnej1 showed the same reduction in the efficiency of plasmid repair, compared to both single deletion strains. Also, using a Homologous Recombination (HR) specific plasmid-based DSB repair assay we observed that deletion of HUR1-A influenced the efficiency of HR repair, suggesting that HUR1 might also play additional roles in other DNA repair pathways.
非同源末端连接（NHEJ）是一种高度保守的途径，用于修复DNA中的双链断裂（DSB）。在此我们表明，酵母中未表征的开放阅读框HUR1（羟基脲抗性1）的缺失会影响NHEJ的效率。我们的发现得到了蛋白质-蛋白质相互作用（PPI）、遗传相互作用和药物敏感性分析的支持。为了评估HUR1在DSB修复中的活性，我们删除了其与PMR1不重叠的区域，称为HUR1-A。我们观察到，与TPK1和NEJ1的缺失相似，与YKU70（对具有突出端而非平端的DNA的NHEJ很重要）不同，HUR1-A的缺失在突出端和平端质粒修复试验中均降低了NHEJ的效率。同样，染色体修复试验表明，当HUR1-A被删除时，修复效率降低。与Hur1p与Tpk1p和Nej1p的功能联系一致，与两个单缺失菌株相比，双突变菌株Δhur1-A/Δtpk1和Δhur1-A/Δnej1在质粒修复效率上表现出相同程度的降低。此外，使用基于同源重组（HR）特异性质粒的DSB修复试验，我们观察到HUR1-A的缺失影响了HR修复的效率，这表明HUR1可能在其他DNA修复途径中也发挥额外作用。
