Identification of a potential transcriptional regulator encoded by grass carp reovirus
- 25 Downloads
Many transcription factors are encoded by DNA viruses and retroviruses due to their regulatory roles in gene expression in the host cell. However, no transcriptional regulator has been identified in any reovirus. Here, a non-structural protein, NS31, encoded by grass carp reovirus genomic segment S7 was characterized. The NS31 protein is predicted to contain a helix-turn-helix (HTH)-like domain and a C-terminal acidic α-helix motif. In yeast, a fusion protein composed of the Gal4-BD domain and NS31 (BD-NS31) was able to activate the expression of reporter genes (Gal1/MEL1 promoter) without the Gal4-AD domain. We also found that NS31 activated the reporter genes in a BD-dependent manner, and both the C- and N-termini contribute to the activation function of NS31. Furthermore, NS31 homologues from other aquareoviruses were also shown to possess a similar transcriptional activation function in yeast. Thus, the aquareovirus NS31 protein appears to act as a transcriptional regulatory protein, the first one identified in a member of the family Reoviridae.
Funding for this research was provided by the National Natural Science Foundation of China (No. 31672690) and the Earmarked Fund for China Agriculture Research System (No. CARS-45-19).
Compliance with ethical standards
Conflict of interest
The authors declare that there are no conflicts of interest.
Animal were handled in accordance with the Guidelines on the Care and Use of Animals for Scientific Purposes provided by the Institutional Animal Care and Use Committee (IACUC) of Shanghai Ocean University (No. SHOU-09-007), Shanghai, China.
- 2.Attoui H, Fang Q, Mohd JF, Cantaloube JF, Biagini P, De MP, De LX (2002) Common evolutionary origin of aquareoviruses and orthoreoviruses revealed by genome characterization of Golden shiner reovirus, Grass carp reovirus, Striped bass reovirus and golden ide reovirus (genus Aquareovirus, family Reoviridae). J Gen Virol 83:1941–1951CrossRefGoogle Scholar
- 3.Bussiere LD, Choudhury P, Bellaire B, Miller CL (2017) Characterization of a replicating mammalian orthoreovirus with tetracysteine tagged μNS for live cell visualization of viral factories. J Virol 91Google Scholar
- 6.Chung KM, Song OK, Jang SK (1997) Hepatitis C virus nonstructural protein 5A contains potential transcriptional activator domains. Mol Cells 7:661–667Google Scholar
- 11.Fang Q, Ke LH (1989) Growth characteristics and high titer culture of grass carp hemorrhage virus (GCHV)-873 in vitro. Virol SinGoogle Scholar
- 12.Fang Q, Seng EK, Ding QQ, Zhang LL (2008) Characterization of infectious particles of grass carp reovirus by treatment with proteases. Adv Virol 153:675–682Google Scholar
- 21.Kato N, Lan KH, Ononita SK, Yoshida H, Shiratori Y, Omata M (1997) Hepatitis C virus nonstructural region 5A protein is a potent transcriptional activator. J Virol 71:8856–8859Google Scholar
- 25.Liu W, Wang H, Yu F, Lu L (2017) Grass carp reovirus outer capsid proteins VP5 and VP7 interact in vitro. Adv Virol 162:2375–2380Google Scholar
- 29.Mohd-Jaafar F, Goodwin AM, Merry G, Fang Q, Cantaloube J, Biagini P, De-Micco P, Mertens P, Attoui H (2008) Complete characterisation of the American grass carp reovirus genome (genus Aquareovirus: family Reoviridae) reveals an evolutionary link between aquareoviruses and coltiviruses. Virology 373:310CrossRefGoogle Scholar
- 31.Pei C, Ke F, Chen ZY, Zhang QY (2014) Complete genome sequence and comparative analysis of grass carp reovirus strain 109 (GCReV-109) with other grass carp reovirus strains reveals no significant correlation with regional distribution. Adv Virol 159:2435–2440Google Scholar
- 32.Rosales R, Harris N, Ahn BY, Moss B (1994) Purification and identification of a vaccinia virus-encoded intermediate stage promoter-specific transcription factor that has homology to eukaryotic transcription factor SII (TFIIS) and an additional role as a viral RNA polymerase subunit. J Biol Chem 269:14260Google Scholar