Amino Acid Substitution K470R in the Nucleoprotein Increases the Virulence of H5N1 Influenza A Virus in Mammals

Chen, Lin; Wang, Chengmin; Luo, Jing; Li, Meng; Liu, Huimin; Zhao, Na; Huang, Jingjing; Zhu, Xili; Ma, Guoyao; Yuan, Guohui; He, Hongxuan

doi:10.3389/fmicb.2017.01308

Cited by 17 publications

(13 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several publications have reported that modifying NP residues can affect the intracell localization of proteins and the later formation of the virion (Ince, Gueye‐Mbaye, Bennink, & Yewdell, ; Ninpan et al, ; Shu, Bean, & Webster, ), which correlates with decreased activity of RNPs formed with mutant NP observed in this study. An example of this was the study of Chen et al (), who found that the modifications of residues 91 and 198 in the influenza A virus NP altered normal NP localization, decreasing RNP activity.…”

Section: Discussionmentioning

confidence: 99%

Development of an Isavirus minigenome system to study the function of the pocket RNA‐binding domain of the viral nucleoprotein (NP) in salmon cells

Toro-Ascuy

Santibáñez

Peña

et al. 2019

Journal of Fish Diseases

View full text Add to dashboard Cite

The Isavirus is an orthomyxovirus with a genome composed of eight segments of negative single‐strand RNA (−ssRNA). It has been proposed that the eight genomic segments of the Isavirus are organized as a ribonucleoprotein (RNP) complex called a minigenome, which contains all the viral RNA segments, a viral heterotrimeric polymerase and multiple copies of the viral nucleoprotein (NP). Here, we develop an Isavirus minigenome system and show the importance of the formation of active RNPs and the role of viral NP R189, R194, R302 and K325 residues in the NP RNA‐binding domain in the context of RNPs. The results indicate it is possible to generate a minigenome in salmon cells, a composite ISAV RNPs with EGFP‐based chimeric vRNA with heterotrimeric polymerase (PB1, PB2, PA) and NP protein using CMV‐based auxiliary plasmids. It was also shown that NP R189, R194, R302 and K325 residues are important to generate viral mRNA from the constituted RNPs and a detectable reporter protein. This work is the first salmon cell‐based minigenome assay for the Isavirus, which was evaluated by a bioinformatic and functional study of the NP protein in viral RNPs, which showed that correct NP‐vRNA interaction is key to the functioning of RNPs.

show abstract

Section: Discussionmentioning

confidence: 99%

Development of an Isavirus minigenome system to study the function of the pocket RNA‐binding domain of the viral nucleoprotein (NP) in salmon cells

Toro-Ascuy

Santibáñez

Peña

et al. 2019

Journal of Fish Diseases

View full text Add to dashboard Cite

show abstract

“…Besides K103, we found five other lysines 91, 198, 227, 229, and 470 of NP could either be modified by acetylation using mass spectrometry. In our previous study, we investigated their functions in influenza virus life cycle ( 36 ). Of these, the K91R and K198R showed decreased the polymerase activity, and K91R and K198R mutants cannot yield recombinant viruses, while K227R viruses showed a similar virulence as rWT.…”

Section: Discussionmentioning

confidence: 99%

“…Moreover, the replication efficiencies of K229R mutant viruses were attenuated in vivo and in vitro . Importantly, rK470R increased the virus’s virulence in both cell culture and animal model ( 36 ). We have also substituted all lysine (K) residues with arginine(R).…”

Section: Discussionmentioning

confidence: 99%

“…Recombinant viruses were generated by plasmid-based reverse genetics as previously described ( 35 , 36 ). In brief, The pHW2000-NP plasmid (as wild-type) or NP gene with mutation K103A and K103R was co-transfected with the other seven plasmids pHW2000-PB1, -PB2, -PA, -HA, -NA, -NS, and -M genes from A/environment/Qinghai/1/2008(H5N1) virus into MDCK cells and 293T cells.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Histone Deacetylase 1 Plays an Acetylation-Independent Role in Influenza A Virus Replication

et al. 2017

Self Cite

View full text Add to dashboard Cite

Influenza A viruses (IAVs) take advantage of the host acetylation system for their own benefit. Whether the nucleoprotein (NP) of IAVs undergoes acetylation and the interaction between the NP and the class I histone deacetylases (HDACs) were largely unknown. Here, we showed that the NP protein of IAV interacted with HDAC1, which downregulated the acetylation level of NP. Using mass spectrometry, we identified lysine 103 as an acetylation site of the NP. Compared with wild-type protein, two K103 NP mutants, K103A and K103R, enhanced replication efficiency of the recombinant viruses in vitro. We further demonstrated that HDAC1 facilitated viral replication via two paths: promoting the nuclear retention of NP and inhibiting TBK1-IRF3 pathway. Our results lead to a new mechanism for regulating NP acetylation, indicating that HDAC1 may be a possible target for antiviral drugs.

show abstract

“…The amino acid mutations S224P, N383D, and I353R in PA increased the virulence of H5N1 influenza virus in mice and ducks (16)(17)(18). The amino acid mutations M105V, I109T, and A184K in NP increased the virulence of H5N1 virus in chickens (19)(20)(21), whereas the K470R mutation in NP increased the virulence of H5N1 virus in mice (22). Two amino acid mutations in M1, N30D and T215A, synergistically increased the virulence of H5N1 virus in mice (23).…”

mentioning

confidence: 99%

Amino Acid Mutations A286V and T437M in the Nucleoprotein Attenuate H7N9 Viruses in Mice

Zhang

Shi

et al. 2020

J Virol

View full text Add to dashboard Cite

The low-pathogenic H7N9 influenza viruses that emerged in 2013 acquired an insertion of four amino acids in their hemagglutinin cleavage site and thereby became highly pathogenic to chickens in 2017. Previous studies indicated that these highly pathogenic H7N9 viruses are virulent in chickens but have distinct pathotypes in mice. A/chicken/Guangdong/SD098/2017 (CK/SD098) is avirulent, with a 50% mouse lethal dose (MLD50) of >7.5 log10 50% egg infectious dose (EID50), whereas A/chicken/Hunan/S1220/2017 (CK/S1220) is virulent in mice, with an MLD50 of 3.2 log10 EID50. In this study, we explored the genetic determinants that contribute to the difference in virulence between these two H7N9 viruses by generating a series of reassortants and mutants in the CK/S1220 virus background and testing their virulence in mice. We found that the reassortant CK/1220-SD098-NP, carrying the nucleoprotein (NP) of CK/SD098, was avirulent in mice, with an MLD50 of >107.5 EID50. The NPs of these two viruses differ by two amino acids, at positions 286 and 437. We further demonstrated that the amino acid mutations A286V and T437M of NP independently slowed the process of NP import to and export from the nucleus and thus jointly impaired the viral life cycle and attenuated the virulence of these H7N9 viruses in mice. Our study identified new virulence determinants in NP and provided novel targets for the development of live attenuated vaccines and antiviral drugs against influenza viruses. IMPORTANCE The H7N9 influenza viruses that emerged in China in 2013 have caused over 1,500 human infections, with a mortality rate of nearly 40%. The viruses were initially low pathogenic but became highly pathogenic in chickens at the beginning of 2017 and caused severe disease outbreaks in poultry. Several studies suggested that the highly pathogenic H7N9 viruses have increased virulence in mammals; however, the genetic basis of the virulence of H7N9 viruses in mammals is not fully understood. Here, we found that two amino acids, 286A and 437T, in NP are prerequisites for the virulence of H7N9 viruses in mice and the mutations A286V and T437M collectively eliminate the virulence of H7N9 viruses in mice. Our study further demonstrated that the virulence of influenza viruses is a polygenic trait, and the newly identified virulence-related residues in NP may provide new targets for attenuated influenza vaccine and antiviral drug development.

show abstract

Amino Acid Substitution K470R in the Nucleoprotein Increases the Virulence of H5N1 Influenza A Virus in Mammals

Cited by 17 publications

References 47 publications

Development of an Isavirus minigenome system to study the function of the pocket RNA‐binding domain of the viral nucleoprotein (NP) in salmon cells

Development of an Isavirus minigenome system to study the function of the pocket RNA‐binding domain of the viral nucleoprotein (NP) in salmon cells

Histone Deacetylase 1 Plays an Acetylation-Independent Role in Influenza A Virus Replication

Amino Acid Mutations A286V and T437M in the Nucleoprotein Attenuate H7N9 Viruses in Mice

Contact Info

Product

Resources

About