State Key Laboratory of Biocontrol, School of Life Sciences, SunYat-Sen (Zhongshan) University, Guangzhou 510275, People's Republic of China.
Arch Virol. 2010 Jul;155(7):1069-76. doi: 10.1007/s00705-010-0684-2. Epub 2010 May 12.
The dUTPase is a ubiquitous and crucial enzyme responsible for regulating cellular levels of dUTP. In the present study, the expression pattern and translocation of a dUTPase homolog encoded by Singapore grouper iridovirus (SGIV) were elucidated. The SGIV ORF049R encodes a dUTPase homolog, which is a peptide of 155 amino acids that contains five conserved motifs. The temporal expression pattern during infection in vitro revealed that the SGIV dUTPase was an early transcript. A leucine-rich nuclear export signal (NES) at the C-terminus was predicted using CBS Online Servers. Subcellular location analysis showed that SGIV dUTPase is a cytoplasmic protein. Site-direct mutagenesis by overlap extension-PCR indicated that the NES is crucial for the translocation of SGIV dUTPase from the nucleus to the cytoplasm. We have discovered for the first time that the NES-dependent translocation of dUTPase is different for SGIV than for members of other species, which depend on a nuclear localization signal. These results provide new insights into the pathogenesis of fish iridoviruses.
dUTP 酶是一种普遍存在且至关重要的酶，负责调节细胞内 dUTP 的水平。在本研究中，阐明了由新加坡石斑鱼虹彩病毒（SGIV）编码的 dUTP 酶同系物的表达模式和易位。SGIV ORF049R 编码 dUTP 酶同系物，该蛋白由 155 个氨基酸组成，包含五个保守基序。体外感染过程中的时程表达模式表明，SGIV dUTP 酶是早期转录物。使用 CBS Online Servers 预测了 C 末端的富含亮氨酸的核输出信号（NES）。亚细胞定位分析表明 SGIV dUTPase 是一种细胞质蛋白。重叠延伸-PCR 的定点诱变表明，NES 对于 SGIV dUTPase 从细胞核到细胞质的易位至关重要。我们首次发现，与依赖核定位信号的其他物种成员不同，SGIV 的 dUTPase 依赖 NES 的易位。这些结果为鱼类虹彩病毒的发病机制提供了新的见解。
