Lysine residues K66, K109, and K110 in the bovine foamy virus transactivator protein are required for transactivation and viral replication

Suzhen Zhang; Xiaoxu Cui; Jing Li; Zhibin Liang; Wentao Qiao; Juan Tan

doi:10.1007/s12250-015-3652-x

April 2016

Suzhen Zhang, Xiaoxu Cui, Jing Li, Zhibin Liang, Wentao Qiao and Juan Tan. Lysine residues K66, K109, and K110 in the bovine foamy virus transactivator protein are required for transactivation and viral replication[J]. Virologica Sinica, 2016, 31(2): 142-149. doi: 10.1007/s12250-015-3652-x

Citation: Suzhen Zhang, Xiaoxu Cui, Jing Li, Zhibin Liang, Wentao Qiao, Juan Tan. Lysine residues K66, K109, and K110 in the bovine foamy virus transactivator protein are required for transactivation and viral replication .VIROLOGICA SINICA, 2016, 31(2) : 142-149. http://dx.doi.org/10.1007/s12250-015-3652-x

牛泡沫病毒反式激活因子第66,109,110位赖氨酸对病毒反式激活能力和复制能力的影响

分子微生物学与技术教育部重点实验室，生命科学学院，南开大学，天津，中国

通讯作者： 谈娟, juantan@nankai.edu.cn, ORCID: 0000-0001-7313-4542
收稿日期： 2015-09-18
录用日期： 2016-01-14
出版日期： 2016-03-11

摘要

牛泡沫病毒（BFV）是一种可感染牛的逆转录病毒。和其他逆转录病毒一样，BFV编码的反式激活因子（BTas）可增强病毒自身启动子的转录活性。BFV 5’LTR上的保守启动子和独特的内部启动子均和BTas蛋白有相互作用。我们的前期结果表明BTas的第66,109,110位赖氨酸可被p300乙酰化，从而增强BTas结合DNA的能力，然而乙酰化赖氨酸位点对BFV复制能力的影响并未见报道。本文为BTas对BFV复制所必须的提供了直接证据并且证实了第66,109,110位赖氨酸对BTas的功能和病毒的复制很重要。本文获得了缺失BTas和BTas第66,109,110位赖氨酸突变精氨酸的感染性克隆；体内实验证明BTas第66,109,110位赖氨酸至精氨酸的突变损伤了BTas对LTR和IP启动子的反式激活能力；在病毒复制水平上，赖氨酸突变降低了病毒蛋白的表达水平，其中BTas 3M感染性克隆突变体不能完成病毒的复制。这些结果表明BTas66,109,110位赖氨酸对BFV复制起着重要的作用，暗示着BTas的乙酰化对病毒的生活周期有一定的调节作用。
- 牛泡沫病毒
- , 感染性克隆
- , BTas
- , 乙酰化赖氨酸
- , 逆转录病毒复制

Lysine residues K66, K109, and K110 in the bovine foamy virus transactivator protein are required for transactivation and viral replication

Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China

Corresponding author: Juan Tan, juantan@nankai.edu.cn
ORCID: 0000-0001-7313-4542
Received Date: 18 September 2015
Accepted Date: 14 January 2016
Published Date: 11 March 2016

Abstract

Bovine foamy virus (BFV) is a complex retrovirus that infects cattle. Like all retroviruses, BFV encodes a transactivator Tas protein (BTas) that increases gene transcription from viral promoters. BFV encodes two promoters that can interact with BTas, a conserved promoter in the 5' long terminal repeat (LTR) and a unique internal promoter (IP). Our previous study showed that BTas is acetylated by p300 at residues K66, K109, and K110, which markedly enhanced the ability of BTas to bind to DNA. However, whether these residues are important for BFV replication was not determined. Therefore, in this study we provide direct evidence that BTas is required for BFV replication and demonstrate that residues K66, K109, and K110 are critical for BTas function and BFV replication. Full-length infectious clones were generated, which were BTas deficient or contained lysine to arginine (K→R) mutations at position 66, 109, and/or 110. In vivo data indicated that K→R mutations at positions 66, 109, and 110 in BTas impaired transactivation of both the LTR and IP promoters. In addition, the K→R mutations in full-length infectious clones reduced expression of viral proteins, and the triple mutant and BTas deletion completely abrogated viral replication. Taken together, these results indicate that lysine residues at positions 66, 109, and 110 in the BTas protein are crucial for BFV replication and suggest a potential role for BTas acetylation in regulating the viral life cycle.
- bovine foamy virus
- , infectious clone
- , BTas
- , acetylated lysines
- , retrovirus replication

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