Physical Interaction between the Herpes Simplex Virus Type 1 Exonuclease, UL12, and the DNA Double-Strand Break-Sensing MRN Complex
Physical Interaction between the Herpes Simplex Virus Type 1 Exonuclease, UL12, and the DNA Double-Strand Break-Sensing MRN Complex
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DOI：
10.1128/jvi.01506-10
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发表时间：
2010-12-01
影响因子：
5.4
通讯作者：
Weller, Sandra K.
中科院分区：
文献类型：
--
作者：
Balasubramanian, Nandakumar;Bai, Ping;Weller, Sandra K.
由UL 12基因编码的单纯疱疹病毒1型（HSV-1）碱性核酸酶在HSV-1复制中起重要作用，因为UL 12无效突变体显示严重的生长缺陷。HSV-1碱性核酸外切酶UL 12与病毒单链DNA结合蛋白ICP 8相互作用，并与ICP 8一起促进体外链交换。我们提出，UL 12和ICP 8形成两个亚基重组酶，使人想起噬菌体λ Red α/β重组系统，并且病毒和细胞重组酶通过同源重组依赖的DNA复制机制促进病毒基因组复制。为了验证这一假设，我们通过免疫共沉淀鉴定了UL 12的细胞相互作用伴侣。我们首次报道了UL 12和细胞MRN复合物组分之间的特异性相互作用，这是ATM介导的同源重组修复（HRR）途径中的一个重要因素。这种相互作用在感染早期就被检测到，不需要病毒DNA或其他病毒或细胞蛋白。负责相互作用的UL 12的区域已经被定位到前125个残基，并且可以通过缺失残基100至126来消除免疫共沉淀。这些观察结果支持了细胞和病毒重组因子共同促进HSV-1有效生长的假设。
The herpes simplex virus type 1 (HSV-1) alkaline nuclease, encoded by the UL12 gene, plays an important role in HSV-1 replication, as a UL12 null mutant displays a severe growth defect. The HSV-1 alkaline exonuclease UL12 interacts with the viral single-stranded DNA binding protein ICP8 and promotes strand exchange in vitro in conjunction with ICP8. We proposed that UL12 and ICP8 form a two-subunit recombinase reminiscent of the phage lambda Red alpha/beta recombination system and that the viral and cellular recombinases contribute to viral genome replication through a homologous recombination-dependent DNA replication mechanism. To test this hypothesis, we identified cellular interaction partners of UL12 by using coimmunoprecipitation. We report for the first time a specific interaction between UL12 and components of the cellular MRN complex, an important factor in the ATM-mediated homologous recombination repair (HRR) pathway. This interaction is detected early during infection and does not require viral DNA or other viral or cellular proteins. The region of UL12 responsible for the interaction has been mapped to the first 125 residues, and coimmunoprecipitation can be abolished by deletion of residues 100 to 126. These observations support the hypothesis that cellular and viral recombination factors work together to promote efficient HSV-1 growth.