Varicella-zoster virus (VZV) ORF17 protein induces RNA cleavage and is critical for replication of VZV at 37 degrees C but not 33 degrees C.
Varicella-zoster virus (VZV) ORF17 protein induces RNA cleavage and is critical for replication of VZV at 37 degrees C but not 33 degrees C.
复制标题
水痘带状疱疹病毒 (VZV) ORF17 蛋白可诱导 RNA 裂解，对于 VZV 在 37 摄氏度（而非 33 摄氏度）下的复制至关重要。
作者：
Hitoshi Sato;L. Callanan;L. Pesnicak;T. Krogmann;J. Cohen
水痘-带状疱疹病毒（VZV）开放阅读框17（ORF 17）与单纯疱疹病毒（HSV）UL 41同源，其编码病毒宿主关闭蛋白（vhs）。HSV vhs诱导mRNA降解和宿主蛋白质合成的快速关闭。ORF 17蛋白的抗体在VZV感染的细胞中检测到46-kDa蛋白。HSV vhs定位于病毒颗粒中，而VZV ORF 17蛋白在病毒颗粒中未检测到。ORF 17蛋白诱导RNA切割，但程度远低于HSV-1 vhs。ORF 17蛋白的表达不抑制β-半乳糖苷酶报告质粒的表达，而HSV 1型vhs废除报告基因表达。构建了两个VZV ORF 17缺失突变体，以研究ORF 17在病毒复制中的作用。虽然ORF 17 VZV突变体在33 ℃下生长至与亲本病毒相似的峰值滴度，但ORF 17突变体在37 ℃下生长至比亲本病毒低20至35倍的滴度。与33 ℃相比，在37 ℃下，ORF 62蛋白在用ORF 17缺失突变体感染的细胞的细胞核和细胞质中以不同的模式分布。用ORF 17缺失突变体接种棉鼠导致潜伏感染水平与接种亲本病毒产生的潜伏感染水平相似。ORF 17蛋白在37 ℃对病毒复制的重要性而不是在33 ℃，表明这种蛋白可能促进病毒在体内某些组织中的生长。
Varicella-zoster virus (VZV) open reading frame 17 (ORF17) is homologous to herpes simplex virus (HSV) UL41, which encodes the viral host shutoff protein (vhs). HSV vhs induces degradation of mRNA and rapid shutoff of host protein synthesis. An antibody to ORF17 protein detected a 46-kDa protein in VZV-infected cells. While HSV vhs is located in virions, VZV ORF17 protein was not detectable in virions. ORF17 protein induced RNA cleavage, but to a substantially lesser extent than HSV-1 vhs. Expression of ORF17 protein did not inhibit expression from a beta-galactosidase reporter plasmid, while HSV type 1 vhs abolished reporter expression. Two VZV ORF17 deletion mutants were constructed to examine the role of ORF17 in virus replication. While the ORF17 VZV mutants grew to peak titers that were similar to those of the parental virus at 33 degrees C, the ORF17 mutants grew to 20- to 35-fold-lower titers than parental virus at 37 degrees C. ORF62 protein was distributed in a different pattern in the nuclei and cytoplasm of cells infected with an ORF17 deletion mutant at 37 degrees C compared to 33 degrees C. Inoculation of cotton rats with the ORF17 deletion mutant resulted in a level of latent infection similar to that produced by inoculation with the parental virus. The importance of ORF17 protein for viral replication at 37 degrees C but not at 33 degrees C suggests that this protein may facilitate the growth of virus in certain tissues in vivo.