Huang Xiaohong, Huang Youhua, Gong Jie, Yan Yang, Qin Qiwei
State Key Laboratory of Biocontrol, School of Life Science, Sun Yat-sen University, 135, West Xingang Road, Guangzhou 510275, China.
Biochem Biophys Res Commun. 2008 Aug 15;373(1):140-5. doi: 10.1016/j.bbrc.2008.06.003. Epub 2008 Jun 11.
Lipopolysaccharide-induced TNF-alpha factor (LITAF), a transcription factor, can regulate tumor necrosis factor alpha (TNF-alpha) transcription. Here, a novel LITAF homolog encoded by Singapore grouper iridovirus (SGIV LITAF) was identified and characterized. The putative SGIV LITAF encoded a protein of 104 amino acids (aa) with a predicted molecular mass of 11.6 kDa. Reverse transcription-PCR (RT-PCR) and Western blot analyses of SGIV-infected cells revealed that SGIV LITAF was an early viral gene. Subcellular localization and immunofluorescence assay revealed that SGIV LITAF expression was distributed predominantly in the cytoplasm, associated with mitochondria. Overexpression of SGIV LITAF induced apoptosis, as shown by increased apoptotic bodies, depolarization of mitochondrial membrane potential (DeltaPsi(m)) and activation of caspase-3. Furthermore, NF-kappaB and NFAT activities were increased in cells expressing SGIV LITAF. This is the first report of the identification and characterization of a viral LITAF homolog involved in virus-host interaction.
脂多糖诱导的肿瘤坏死因子α因子（LITAF）是一种转录因子，可调节肿瘤坏死因子α（TNF-α）的转录。在此，鉴定并表征了由新加坡石斑鱼虹彩病毒编码的一种新型LITAF同源物（SGIV LITAF）。推测的SGIV LITAF编码一个由104个氨基酸（aa）组成的蛋白质，预测分子量为11.6 kDa。对感染SGIV的细胞进行逆转录聚合酶链反应（RT-PCR）和蛋白质印迹分析表明，SGIV LITAF是一个早期病毒基因。亚细胞定位和免疫荧光分析显示，SGIV LITAF的表达主要分布在细胞质中，与线粒体相关。如凋亡小体增加、线粒体膜电位（ΔΨm）去极化和半胱天冬酶-3激活所示，SGIV LITAF的过表达诱导细胞凋亡。此外，在表达SGIV LITAF的细胞中，核因子κB（NF-κB）和活化T细胞核因子（NFAT）的活性增加。这是关于参与病毒-宿主相互作用的病毒LITAF同源物鉴定和表征的首次报道。
