Zhao Li-chan, Cheng An-chun, Wang Ming-shu, Yuan Gui-ping, Jia Ren-Yong, Zhou Deng-chun, Qi Xue-Feng, Ge Han, Sun Tao
Avian Diseases Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Yaan, Sichuan, 625014, China.
Avian Dis. 2008 Jun;52(2):324-31. doi: 10.1637/8169-110607-ResNote.1.
Deoxyuridine triphosphatase (dUTPase) is a ubiquitous and important enzyme that hydrolyzes dUTP to dUMP. Many viruses encode virus-specific dUTPase, which plays an essential role in maintaining the integrity of the viral DNA both by reducing the dUTP levels and by providing the substrate for the thymidylate synthase. A 1344-bp gene of duck enteritis virus (DEV) homologous to herpesviral dUTPase was first reported in this paper. The gene encodes a protein of 477 amino acids, with a predicted molecular mass of 49.7 kDa. Multiple sequence alignment suggested that DEV dUTPase was quite similar to other identified herpesviral dUTPase and functioned as a homotrimer. The five conserved motifs of DEV dUTPase with 3-1-2-4-5 arrangement have been recognized, and the phylogenetic analysis showed that DEV dUTPase was genetically close to the avian herpesvirus. Furthermore, RNA dot blot, western blot, and immunofluorescence analysis indicated that the enzyme was expressed at early and late stages after infection. Immunofluorescence also confirmed that DEV dUTPase localized in the cytoplasm of DEV-infected duck embryo fibroblasts as early as 4 hr postinfection (hpi). Later, the enzyme transferred from cytoplasm to nucleus at 8 hpi, and then reached its expression peak at 12 hpi, both in the cytoplasm and nucleus. The results suggested that the DEV dUTPase gene might be an early viral gene in DEV vitro infection and contribute to ensuring the fidelity of genome replication.
脱氧尿苷三磷酸酶（dUTPase）是一种普遍存在且重要的酶，它能将dUTP水解为dUMP。许多病毒编码病毒特异性的dUTPase，该酶通过降低dUTP水平和为胸苷酸合成酶提供底物，在维持病毒DNA的完整性方面发挥着至关重要的作用。本文首次报道了鸭肠炎病毒（DEV）中一个与疱疹病毒dUTPase同源的1344 bp基因。该基因编码一个由477个氨基酸组成的蛋白质，预测分子量为49.7 kDa。多序列比对表明，DEV dUTPase与其他已鉴定的疱疹病毒dUTPase非常相似，且以同源三聚体形式发挥作用。DEV dUTPase具有3-1-2-4-5排列的五个保守基序已被识别，系统发育分析表明，DEV dUTPase在基因上与禽疱疹病毒关系密切。此外，RNA斑点印迹、蛋白质免疫印迹和免疫荧光分析表明，该酶在感染后的早期和晚期均有表达。免疫荧光还证实，DEV dUTPase早在感染后4小时（hpi）就定位于DEV感染的鸭胚成纤维细胞的细胞质中。随后，该酶在8 hpi时从细胞质转移到细胞核，然后在12 hpi时在细胞质和细胞核中均达到表达峰值。结果表明，DEV dUTPase基因可能是DEV体外感染中的一个早期病毒基因，有助于确保基因组复制的保真度。
