Amino acid at position 176 was essential for porcine reproductive and respiratory syndrome virus (PRRSV) non-structural protein 1α (nsp1α) as an inhibitor to the induction of IFN-β

2012 ◽  
Vol 280 (2) ◽  
pp. 125-131 ◽  
Author(s):  
Xibao Shi ◽  
Jing Chen ◽  
Guangxu Xing ◽  
Xiaozhuan Zhang ◽  
Xiaofei Hu ◽  
...  
Virology ◽  
2012 ◽  
Vol 433 (2) ◽  
pp. 431-439 ◽  
Author(s):  
Lalit K. Beura ◽  
Sakthivel Subramaniam ◽  
Hiep L.X. Vu ◽  
Byungjoon Kwon ◽  
Asit K. Pattnaik ◽  
...  

2020 ◽  
Vol 4 (4) ◽  
pp. 857-867
Author(s):  
Bui Anh Thy ◽  
Lê Thanh Hòa ◽  
Trần Xuân Hạnh ◽  
Trần Linh Thước

In this study, we compared the genetic mutation and virulence of the attenuated PRRSV strains obtained by 95 serial passages in Marc-145 cells with the parental virulent strain (designated as BG81) isolated in Vietnam. Results showed that there were marked changes in virulence: pigs inoculated with BG81 exhibited high fever ( 41◦C), which lasted for 12 days, and presented typical clinical symptoms of PRRSV; otherwise, pigs inoculated with BG895 (from passage 95), maintained mean rectal temperature from 39,5oC to 39,9oC, did not develop any significant clinical symptoms. Whole genomes of the attenuated strains were significantly different, but their sequence lengths were conserved, i.e., 15,321 nucleotides. The attenuated strain from passage 95 (BG895) contained 38 nucleotide substitutions that resulted in 14 amino acid changes. Most of these changes (about 65%) occurred before passage 50. The 14 amino acid changes were distributed in Nsp1, Nsp4, Nsp9, Nsp10, GP2, E, GP3, GP4, GP5 and N. Specially, there were two single substitutes within a codon in ORF3, corresponding to parallel mutation at position F143L. However, structural protein (M) and eight non-structural proteins (Nsp2, Nsp3, Nsp5, Nsp6, Nsp7, Nsp8, Nsp11 and Nsp12) among the 19 PRRSV proteins, remained conserved, without any mutations and supposed for consideration as irrelative to the attenuation process. It is interesting that in the gene coding for the smallest structural protein (E protein), there was the highest mutation rate among all of the structural genes analyzed, and genetically, seemed to be a highly variable region. These changes may provide the molecular bases for the observation of the attenuated phenotype in pigs. Thus, our variation results obtained between the attenuated BG895 and the parental virulent BG81 strains provide appropriate molecular data for potential use to test and control the masterseed strain in production of a PRRSV vaccine in Vietnam.


Amino Acids ◽  
2014 ◽  
Vol 47 (1) ◽  
pp. 147-152
Author(s):  
Giovanni Minervini ◽  
Alessandro Masiero ◽  
Emilio Potenza ◽  
Silvio C. E. Tosatto

2020 ◽  
Author(s):  
Jucai Wang ◽  
Yunchao Liu ◽  
Yumei Chen ◽  
Teng Zhang ◽  
Aiping Wang ◽  
...  

Abstract Background: Porcine parvovirus (PPV) is a major cause of reproductive failure in swine, and has caused huge losses throughout the world. Viral protein 2 (VP2) of PPV is a major structural protein that can self-assemble into virus-like particles (VLP) with hemagglutination (HA) activity. In order to identify the essential residues involved in the mechanism of capsid assembly and to further understand the function of HA, we analyzed a series of deletion mutants and site-directed mutations within the N-terminal of VP2 in the Escherichia coli (E. coli) system. Results: Our results showed that deletion of first 47 amino acids from the N-terminal of VP2 protein did not affect capsid assembly, and further truncation to residue 48 Asparagine (Asn, N) caused detrimental effects. Site-directed mutagenesis experiments demonstrated that residue 47Asn reduced the assembly efficiency of PPV VLP, while residue 48Asn destroyed the stability, hemagglutination, and self-assembly characteristics of the PPV VP2 protein. These findings indicated that the residues 47Asn and 48Asn are important amino acid sites to capsid assembly and HA activity. Results from Native PAGE inferred that macromolecular polymers were critical intermediates of the VP2 protein during the capsid assembly process. Site-directed mutation at 48Asn did not affect the association of monomers to form into oligomers, but destroyed the ability of oligomers to assemble into macromolecular particles, influencing both capsid assembly and HA activity. Conclusions: These results demonstrated that PPV capsid assembly is a complex process that is regulated by amino acids 47Asn and 48Asn, which are located at the N-terminal of VP2 and closely related to the association of macromolecular particles. Our findings provide valuable information on the mechanisms of PPV capsid assembly and the possibility of chimeric VLP vaccine development by replacing as much as 47 amino acids at the N-terminal of VP2 protein.


Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1046 ◽  
Author(s):  
Seon-Ju Yeo ◽  
Duc-Duong Than ◽  
Hong-Seog Park ◽  
Haan Woo Sung ◽  
Hyun Park

A novel avian influenza virus (A/wild duck/Korea/K102/2018) (H2N9) was isolated from wild birds in South Korea in 2018, and phylogenetic and molecular analyses were conducted on complete gene sequences obtained by next-generation sequencing. Phylogenetic analysis indicated that the hemagglutinin (HA) and neuraminidase (NA) genes of the A/wild duck/Korea/K102/2018 (H2N9) virus belonged to the Eurasian countries, whereas other internal genes (polymerase basic protein 1 (PB1), PB2, nucleoprotein (NP), polymerase acidic protein (PA), matrix protein (M), and non-structural protein (NS)) belonged to the East Asian countries. A monobasic amino acid (PQIEPR/GLF) at the HA cleavage site, E627 in the PB2 gene, and no deletion of the stalk region in the NA gene indicated that the A/wild duck/Korea/K102/2018 (H2N9) isolate was a typical low pathogenicity avian influenza (LPAI). Nucleotide sequence similarity analysis of HA revealed that the highest homology (98.34%) is to that of A/duck/Mongolia/482/2015 (H2N3), and amino acid sequence of NA was closely related to that of A/duck/Bangladesh/8987/2010 (H10N9) (96.45%). In contrast, internal genes showed homology higher than 98% compared to those of other isolates derived from duck and wild birds of China or Japan in 2016–2018. The newly isolated A/wild duck/Korea/K102/2018 (H2N9) strain is the first reported avian influenza virus in Korea, and may have evolved from multiple genotypes in wild birds and ducks in Mongolia, China, and Japan.


Viruses ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 535 ◽  
Author(s):  
Leslie Barclay ◽  
Jennifer L. Cannon ◽  
Mary E. Wikswo ◽  
Annie R. Phillips ◽  
Hannah Browne ◽  
...  

Noroviruses evolve by antigenic drift and recombination, which occurs most frequently at the junction between the non-structural and structural protein coding genomic regions. In 2015, a novel GII.P16-GII.4 Sydney recombinant strain emerged, replacing the predominance of GII.Pe-GII.4 Sydney among US outbreaks. Distinct from GII.P16 polymerases detected since 2010, this novel GII.P16 was subsequently detected among GII.1, GII.2, GII.3, GII.10 and GII.12 viruses, prompting an investigation on the unique characteristics of these viruses. Norovirus positive samples (n = 1807) were dual-typed, of which a subset (n = 124) was sequenced to yield near-complete genomes. CaliciNet and National Outbreak Reporting System (NORS) records were matched to link outbreak characteristics and case outcomes to molecular data and GenBank was mined for contextualization. Recombination with the novel GII.P16 polymerase extended GII.4 Sydney predominance and increased the number of GII.2 outbreaks in the US. Introduction of the novel GII.P16 noroviruses occurred without unique amino acid changes in VP1, more severe case outcomes, or differences in affected population. However, unique changes were found among NS1/2, NS4 and VP2 proteins, which have immune antagonistic functions, and the RdRp. Multiple polymerase-capsid combinations were detected among GII viruses including 11 involving GII.P16. Molecular surveillance of protein sequences from norovirus genomes can inform the functional importance of amino acid changes in emerging recombinant viruses and aid in vaccine and antiviral formulation.


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