The IR4 auxiliary regulatory protein expands the in vitro host range of equine herpesvirus 1 and is essential for pathogenesis in the murine model.
The IR4 auxiliary regulatory protein expands the in vitro host range of equine herpesvirus 1 and is essential for pathogenesis in the murine model.
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DOI：
10.1016/j.virol.2008.10.017
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发表时间：
2009-01-20
期刊：
影响因子：
3.7
通讯作者：
O'Callaghan, Dennis J.
中科院分区：
文献类型：
--
作者：
Breitenbach, Jonathan E.;Ebner, Paul D.;O'Callaghan, Dennis J.
IR 4是马疱疹病毒1型（EHV-1）的早期调节蛋白，它不是DNA结合蛋白，但与唯一的立即早期蛋白（IEP）相互作用以增加IEP位点特异性DNA结合和IEP介导的EHV-1启动子的反式激活。为了研究IR 4的生物学特性并确定这种调节蛋白是否是病毒生长所必需的，采用细菌人工染色体方法来产生IR 4无效的EHV-1。IR 4基因在非永生化的马NBL-6细胞中对EHV-1的生长是抑制的，但病毒复制被延迟并减少了10倍以上。此外，IR 4突变体的复制在所有其他测试的细胞类型中被消除，包括马ETCC肿瘤细胞和小鼠、兔、猴和人来源的细胞。此外，与高致病性亲本病毒相反，通过评估体重和临床体征判断，IR 4缺失突变体不能在CBA小鼠中引起疾病，并且不能在鼠肺中复制。为了确定阻断IR 4缺失病毒复制的性质，在用IR 4缺失病毒感染的RK-13兔细胞中进行了分子分析，并揭示：1）唯一IEP的合成不受抑制; 2）所检测的早期病毒蛋白质的合成不受影响或延迟到晚期; 3）病毒DNA复制被抑制超过99.9%;和4）必需的晚期蛋白如糖蛋白D和糖蛋白K的合成被阻止。这些发现表明，IR 4蛋白是EHV-1 DNA在非允许细胞中复制所需的，并且与其他α疱疹病毒中的同源物一样，有助于病毒在多种细胞类型中复制所需的功能。
IR4, an early regulatory protein of equine herpesvirus 1 (EHV-1), is not a DNA-binding protein, but interacts with the sole immediate-early protein (IEP) to increase both IEP site-specific DNA-binding and IEP-mediated trans-activation of EHV-1 promoters. To investigate the biological properties of IR4 and ascertain whether this regulatory protein is essential for virus growth, bacterial artificial chromosome methods were employed to generate an IR4-null EHV-1. The IR4 gene was dispensable for EHV-1 growth in non-immortalized equine NBL-6 cells, but virus replication was delayed and was reduced by greater than 10-fold. In addition, replication of the IR4 mutant was abrogated in all other cell types tested, including equine ETCC tumor cells and cells of mouse, rabbit, monkey, and human origin. Further, in contrast to the highly pathogenic parent virus, the IR4 deletion mutant failed to cause disease in the CBA mouse as judged by assessing body weight and clinical signs and was unable to replicate in the murine lung. To define the nature of the block in the replication of the IR4-null virus, molecular analyses were carried out in RK-13 rabbits' cells infected with the IR4-deleted virus and revealed that: 1) the synthesis of the sole IEP was not inhibited; 2) the synthesis of early viral proteins examined was either not affected or was delayed to late times; 3) viral DNA replication was inhibited by more than 99.9%; and 4) synthesis of essential late proteins such as glycoprotein D and glycoprotein K was prevented. These findings indicate that the IR4 protein is required for EHV-1 DNA replication in non-permissive cells, and, like its homologues in other alphaherpesviruses, contributes a function required for virus replication in a variety of cell types.
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影响因子：
3.7
作者：
Ahn, Byung Chul;Breitenbach, Jonathan E.;O'Callaghan, Dennis J.
通讯作者：
O'Callaghan, Dennis J.
影响因子：
3.7
作者：
BAUMANN, RP;STACZEK, J;OCALLAGHAN, DJ
通讯作者：
OCALLAGHAN, DJ
影响因子：
5.4
作者：
Chen, M;Harty, RN;OCallaghan, DJ
通讯作者：
OCallaghan, DJ
影响因子：
5.4
作者：
Derbigny, WA;Kim, SK;O'Callaghan, DJ
通讯作者：
O'Callaghan, DJ
影响因子：
5.4
作者：
HOLDEN, VR;YALAMANCHILI, RR;OCALLAGHAN, DJ
通讯作者：
OCALLAGHAN, DJ