He Fang, Kwang Jimmy
Animal Health Biotechnology, Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore.
Virol J. 2008 Dec 17;5:151. doi: 10.1186/1743-422X-5-151.
White spot syndrome virus (WSSV) is one major pathogen in shrimp aquaculture. WSSV ORF403 is predicted to encode a protein of 641 amino acids, which contains a C3H2C2 RING structure. In the presence of an E2 conjugating enzyme from shrimp, WSSV403 can ubiquitinate itself in vitro, indicating it can function as a viral E3 ligase. Besides, WSSV403 E3 ligase can be activated by a series of E2 variants. Based on RT-PCR and Real time PCR, we detected transcription of WSSV403 in the commercial specific-pathogen-free (SPF) shrimp, suggesting its role as a latency-associated gene. Identified in yeast two-hybrid screening and verified by pull-down assays, WSSV403 is able to bind to a shrimp protein phosphatase (PPs), which was characterized before as an interaction partner for another latent protein WSSV427. Our studies suggest that WSSV403 is a regulator of latency state of WSSV by virtue of its E3 ligase function.
白斑综合征病毒（WSSV）是对虾养殖业中的一种主要病原体。WSSV的ORF403预计编码一种含有641个氨基酸的蛋白质，该蛋白质含有一个C3H2C2型泛素连接酶结构域。在存在来自对虾的E2缀合酶的情况下，WSSV403能够在体外进行自身泛素化，这表明它可以作为一种病毒E3连接酶发挥作用。此外，WSSV403 E3连接酶可以被一系列E2变体激活。基于逆转录-聚合酶链反应（RT-PCR）和实时荧光定量聚合酶链反应（Real time PCR），我们在商业化的无特定病原体（SPF）对虾中检测到了WSSV403的转录，这表明它作为一个潜伏相关基因发挥作用。在酵母双杂交筛选中鉴定并通过下拉试验验证，WSSV403能够与一种对虾蛋白磷酸酶（PPs）结合，该蛋白磷酸酶之前被鉴定为另一种潜伏蛋白WSSV427的相互作用伴侣。我们的研究表明，WSSV403凭借其E3连接酶功能，是WSSV潜伏状态的一个调节因子。
