scholarly journals Type-IInterferon-Inducible SERTAD3 Inhibits Influenza A Virus Replication by Blocking the Assembly of Viral RNA Polymerase Complex

Cell Reports ◽  
2020 ◽  
Vol 33 (5) ◽  
pp. 108342
Author(s):  
Nina Sun ◽  
Chunfeng Li ◽  
Xiao-Feng Li ◽  
Yong-Qiang Deng ◽  
Tao Jiang ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Influenza A Virus ◽  
Virus Replication ◽  
Influenza A ◽  
Viral Rna ◽  
Polymerase Complex

scholarly journals A mechanism for prime-realignment during influenza A virus replication

2017 ◽  
Author(s):  
Judith Oymans ◽  
Aartjan J.W. te Velthuis
Keyword(s):  
Influenza Virus ◽  
Rna Polymerase ◽  
Viral Replication ◽  
Influenza A Virus ◽  
Virus Replication ◽  
Influenza A ◽  
De Novo ◽  
Severe Disease ◽  
Viral Rna ◽  
Insight Into

AbstractThe influenza A virus genome consists of eight segments of single-stranded RNA. These segments are replicated and transcribed by a viral RNA-dependent RNA polymerase (RdRp) that is made up of the influenza virus proteins PB1, PB2 and PA. To copy the viral RNA (vRNA) genome segments and the complementary RNA (cRNA) segments, the replicative intermediate of viral replication, the RdRp must use two promoters and two differentde novoinitiation mechanisms. On the vRNA promoter, the RdRp initiates on the 3’ terminus, while on the cRNA promoter the RdRp initiates internally and subsequently realigns the nascent vRNA product to ensure that the template is copied in full. In particular the latter process, which is also used by other RNA viruses, is not understood. Here we provide mechanistic insight into prime-realignment during influenza virus replication and show that it is controlled by the priming loop and a helix-loop-helix motif of the PB1 subunit of the RdRp. Overall, these observations advance our understanding of how the influenza A virus initiates viral replication and amplifies the genome correctly.ImportanceInfluenza A viruses cause severe disease in humans and are considered a major threat to our economy and health. The viruses replicate and transcribe their genome using an enzyme called the RNA polymerases. To ensure that the genome is amplified faithfully and abundant viral mRNAs are made for viral protein synthesis, the RNA polymerase must work correctly. In this report, we provide insight into the mechanism that the RNA polymerase employs to ensure that the viral genome is copied correctly.

scholarly journals The host factor ANP32A is required for influenza A virus vRNA and cRNA synthesis

2021 ◽  
Author(s):  
Benjamin E. Nilsson-Payant ◽  
Benjamin R. tenOever ◽  
Aartjan J.W. te Velthuis
Keyword(s):  
Avian Influenza ◽  
Rna Polymerase ◽  
Viral Replication ◽  
Influenza A Virus ◽  
Virus Replication ◽  
Influenza A ◽  
Host Factor ◽  
Rna Polymerases ◽  
Viral Rna ◽  
Influenza A Viruses

Influenza A viruses are negative-sense RNA viruses that rely on their own viral replication machinery to replicate and transcribe their segmented single-stranded RNA genome. The viral ribonucleoprotein complexes in which viral RNA is replicated consist of a nucleoprotein scaffold around which the RNA genome is bound, and a heterotrimeric RNA-dependent RNA polymerase that catalyzes viral replication. The RNA polymerase copies the viral RNA (vRNA) via a replicative intermediate, called the complementary RNA (cRNA), and subsequently uses this cRNA to make more vRNA copies. To ensure that new cRNA and vRNA molecules are associated with ribonucleoproteins in which they can be amplified, the active RNA polymerase recruits a second polymerase to encapsidate the cRNA or vRNA. Host factor ANP32A has been shown to be essential for viral replication and to facilitate the formation of a dimer between viral RNA polymerases. Differences between mammalian and avian ANP32A proteins are sufficient to restrict viral replication. It has been proposed that ANP32A is only required for the synthesis of vRNA molecules from a cRNA, but not vice versa. However, this view does not match recent molecular evidence. Here we use minigenome assays, virus infections, and viral promoter mutations to demonstrate that ANP32A is essential for both vRNA and cRNA synthesis. Moreover, we show that ANP32 is not only needed for the actively replicating polymerase, but also for the polymerase that is encapsidating nascent viral RNA products. Overall, these results provide new insights into influenza A virus replication and host adaptation. IMPORTANCE Zoonotic avian influenza A viruses pose a constant threat to global health, and they have the potential to cause pandemics. Species variations in host factor ANP32A play a key role in supporting the activity of avian influenza A virus RNA polymerases in mammalian hosts. Here we show that ANP32A acts at two stages in the influenza A virus replication cycle, supporting recent structural experiments, in line with its essential role. Understanding how ANP32A supports viral RNA polymerase activity and how it supports avian polymerase function in mammalian hosts is important for understanding influenza A virus replication and the development of antiviral strategies against influenza A viruses.

scholarly journals A Mechanism for Priming and Realignment during Influenza A Virus Replication

2017 ◽  
Vol 92 (3) ◽  
Author(s):  
Judith Oymans ◽  
Aartjan J. W. te Velthuis
Keyword(s):  
Influenza Virus ◽  
Rna Polymerase ◽  
Viral Replication ◽  
Influenza A Virus ◽  
Virus Replication ◽  
Influenza A ◽  
De Novo ◽  
Severe Disease ◽  
Viral Rna ◽  
Insight Into

ABSTRACTThe influenza A virus genome consists of eight segments of single-stranded RNA. These segments are replicated and transcribed by a viral RNA-dependent RNA polymerase (RdRp) that is made up of the influenza virus proteins PB1, PB2, and PA. To copy the viral RNA (vRNA) genome segments and the cRNA segments, the replicative intermediate of viral replication, the RdRp must use two promoters and two differentde novoinitiation mechanisms. On the vRNA promoter, the RdRp initiates on the 3′ terminus, while on the cRNA promoter, the RdRp initiates internally and subsequently realigns the nascent vRNA product to ensure that the template is copied in full. In particular, the latter process, which is also used by other RNA viruses, is not understood. Here we provide mechanistic insight into priming and realignment during influenza virus replication and show that it is controlled by the priming loop and a helix-loop-helix motif of the PB1 subunit of the RdRp. Overall, these observations advance our understanding of how the influenza A virus initiates viral replication and amplifies the genome correctly.IMPORTANCEInfluenza A viruses cause severe disease in humans and are considered a major threat to our economy and health. The viruses replicate and transcribe their genome by using an enzyme called the RNA polymerases. To ensure that the genome is amplified faithfully and that abundant viral mRNAs are made for viral protein synthesis, the RNA polymerase must work correctly. In this report, we provide insight into the mechanism that the RNA polymerase employs to ensure that the viral genome is copied correctly.

Viral RNA Polymerase: A Promising Antiviral Target for Influenza A Virus

2013 ◽  
Vol 20 (31) ◽  
pp. 3923-3934 ◽  
Author(s):  
Fangyuan Shi ◽  
Yuanchao Xie ◽  
Lifang Shi ◽  
Wenfang Xu
Keyword(s):  
Rna Polymerase ◽  
Influenza A Virus ◽  
Influenza A ◽  
Viral Rna

scholarly journals The Fight against the Influenza A Virus H1N1: Synthesis, Molecular Modeling, and Biological Evaluation of Benzofurazan Derivatives as Viral RNA Polymerase Inhibitors

ChemMedChem ◽  
2013 ◽  
Vol 9 (1) ◽  
pp. 129-150 ◽  
Author(s):  
Mafalda Pagano ◽  
Daniele Castagnolo ◽  
Martina Bernardini ◽  
Anna Lucia Fallacara ◽  
Ilaria Laurenzana ◽  
...  
Keyword(s):  
Molecular Modeling ◽  
Rna Polymerase ◽  
Influenza A Virus ◽  
Influenza A ◽  
Biological Evaluation ◽  
Viral Rna ◽  
Virus H1n1 ◽  
Polymerase Inhibitors

scholarly journals The human H5N1 influenza A virus polymerase complex is active in vitro over a broad range of temperatures, in contrast to the WSN complex, and this property can be attributed to the PB2 subunit

2008 ◽  
Vol 89 (12) ◽  
pp. 2923-2932 ◽  
Author(s):  
Birgit G. Bradel-Tretheway ◽  
Z. Kelley ◽  
Shikha Chakraborty-Sett ◽  
Toru Takimoto ◽  
Baek Kim ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Influenza A Virus ◽  
Influenza A ◽  
Elevated Temperatures ◽  
Expression System ◽  
Lung Epithelial Cells ◽  
Upper Respiratory Tract ◽  
Polymerase Complex ◽  
H5n1 Influenza

Influenza A virus (IAV) replicates in the upper respiratory tract of humans at 33 °C and in the intestinal tract of birds at close to 41 °C. The viral RNA polymerase complex comprises three subunits (PA, PB1 and PB2) and plays an important role in host adaptation. We therefore developed an in vitro system to examine the temperature sensitivity of IAV RNA polymerase complexes from different origins. Complexes were prepared from human lung epithelial cells (A549) using a novel adenoviral expression system. Affinity-purified complexes were generated that contained either all three subunits (PA/PB1/PB2) from the A/Viet/1203/04 H5N1 virus (H/H/H) or the A/WSN/33 H1N1 strain (W/W/W). We also prepared chimeric complexes in which the PB2 subunit was exchanged (H/H/W, W/W/H) or substituted with an avian PB2 from the A/chicken/Nanchang/3-120/01 H3N2 strain (W/W/N). All complexes were functional in transcription, cap-binding and endonucleolytic activity. Complexes containing the H5N1 or Nanchang PB2 protein retained transcriptional activity over a broad temperature range (30–42 °C). In contrast, complexes containing the WSN PB2 protein lost activity at elevated temperatures (39 °C or higher). The E627K mutation in the avian PB2 was not required for this effect. Finally, the avian PB2 subunit was shown to confer enhanced stability to the WSN 3P complex. These results show that PB2 plays an important role in regulating the temperature optimum for IAV RNA polymerase activity, possibly due to effects on the functional stability of the 3P complex.

Inhibition of influenza A virus replication by RNA interference targeted against the PB1 subunit of the RNA polymerase gene

2011 ◽  
Vol 156 (11) ◽  
pp. 1979-1987 ◽  
Author(s):  
Wanyi Li ◽  
Xiaofan Yang ◽  
Yan Jiang ◽  
Baoning Wang ◽  
Yuan Yang ◽  
...  
Keyword(s):  
Rna Interference ◽  
Rna Polymerase ◽  
Influenza A Virus ◽  
Virus Replication ◽  
Influenza A ◽  
Polymerase Gene ◽  
Rna Polymerase Gene

scholarly journals The host factor ANP32A is required for influenza A virus vRNA and cRNA synthesis

2021 ◽  
Author(s):  
Benjamin E Nilsson-Payant ◽  
Benjamin R. tenOever ◽  
Aartjan J.W. te Velthuis
Keyword(s):  
Rna Polymerase ◽  
Viral Replication ◽  
Influenza A Virus ◽  
Influenza A ◽  
Host Factor ◽  
Viral Rna ◽  
Molecular Evidence ◽  
Influenza A Viruses ◽  
Ribonucleoprotein Complexes ◽  
Rna Genome

Influenza A viruses are negative-sense RNA viruses that rely on their own viral replication machinery to replicate and transcribe their segmented single-stranded RNA genome. The viral ribonucleoprotein complexes in which viral RNA is replicated consist of a nucleoprotein scaffold around which the RNA genome is bound, and a heterotrimeric RNA-dependent RNA polymerase that catalyzes viral replication. The RNA polymerase copies the viral RNA (vRNA) via a replicative intermediate, called the complementary RNA (cRNA), and subsequently uses this cRNA to make more vRNA copies. To ensure that new cRNA and vRNA molecules are associated with ribonucleoproteins in which they can be amplified, the active RNA polymerase recruits a second polymerase to encapsidate the cRNA or vRNA. Host factor ANP32A has been shown to be essential for viral replication and to facilitate the formation of a dimer between viral RNA polymerases and differences between mammalian and avian ANP32A proteins are sufficient to restrict viral replication. It has been proposed that ANP32A is only required for the synthesis of vRNA molecules from a cRNA, but not vice versa. However, this view does not match recent molecular evidence. Here we use minigenome assays, virus infections, and viral promoter mutations to demonstrate that ANP32A is essential for both vRNA and cRNA synthesis. Moreover, we show that ANP32 is not only needed for the actively replicating polymerase, but also for the polymerase that is encapsidating nascent viral RNA products. Overall, these results provide new insights into influenza A virus replication and host adaptation.

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