Porcine circovirus type 2 capsid protein induces unfolded protein response with subsequent activation of apoptosis.

Porcine circovirus type 2 (PCV2) has recently been reported to elicit the unfolded protein response (UPR) via activation of the PERK/eIF2α (RNA-activated protein kinase-like endoplasmic reticulum (ER) kinase/eukaryotic initiation factor 2α) pathway. This study attempted to examine which viral protein might be involved in inducing UPR and whether this cellular event would lead to apoptosis of the cells expressing the viral protein. By transient expression, we found that both replicase (Rep) and capsid (Cap) proteins of PCV2 could induce ER stress as shown by increased phosphorylation of PERK with subsequent activation of the eIF2α-ATF4 (activating transcription factor 4)-CHOP (CCAAT/enhancer-binding protein homologous protein) axis.

Establishment and evaluation of stable cell lines inhibiting foot-and-mouth disease virus by RNA interference.

RNA interference (RNAi) has been proved to be a powerful tool for foot-and-mouth disease virus FMDV inhibition in vitro and in vivo. We established five stable baby hamster kidney 21 cell lines (BHK-21) containing five short hairpin RNAs (shRNAs) expression plasmids (p3D1shRNA, p3D2shRNA, p3D3shRNA, p3D4shRNA, and p3D5shRNA) targeting 3D gene of FMDV. Immunofluorescent assay, virus titration, and real-time quantitative reverse transcription polymerase chain reaction (Q-RT-PCR) were conducted to detect the effect of shRNAs on FMDV replication.

The characteristic of codon usage pattern and its evolution of hepatitis C virus.

To give a new perspective on the codon usage of the hepatitis C virus (HCV) and the factors accounting for shaping the codon usage pattern of the virus, the relative synonymous codon usage (RSCU) values, aromaticity and hydrophobicity of each polyprotein of the virus, effective number of codons (ENC) values and nucleotide contents were calculated to implement a comparative analysis to evaluate the dynamics of the virus evolution. The RSCU values of each codon of 144 HCV ORFs indicated that all abundant codons were C/G-ended codons. The plots of principal component analysis based on sub-genotype of HCV indicated that sub-genotype 1a and 1b separated clearly on the axis of f2 suggesting that the codon usage bias between sub-genotype 1a and 1b strains was different.

Comparative analysis of ovine adenovirus 287 and human adenovirus 2 and 5 based on their codon usage.

Ovine adenovirus 287 (OAdV287) emerges as one of the most promising gene vectors resulting from its unique biological characteristics. To obtain a more detailed knowledge about the codon usage of OAdV287, a comparative study based on the codon usage of OAdV287 and the prototypes of human adenovirus serotypes 2 and 5 (HAdV2/5) was carried out. Some commonly used indices measuring the codon usage patterns, including effective number of codons, relative synonymous codon usage, and statistical methods, were adopted.

Analysis of codon usage in type 1 and the new genotypes of duck hepatitis virus.

In this study, an abundant (A+U)% and low codon bias were revealed in duck hepatitis virus type 1 (DHV-1) and the new serotype strains isolated from Taiwan, South Korea and Mainland China (DHV-N). The general correlation between base composition and codon usage bias suggests that mutational pressure rather than natural selection is the main factor that determines the codon usage bias in these samples. By comparative analysis of the codon usage patterns of 40 ORFs of DHV, we found that all of DHV-1 strains grouped in genotype C; the DHV-N strains isolated in South Korea and China clustered into genotypes B; and the DHV-N strains isolated from Taiwan clustered into genotypes A.

Analysis of codon usage and nucleotide composition bias in polioviruses.

Background: Poliovirus, the causative agent of poliomyelitis, is a human enterovirus and a member of the family of Picornaviridae and among the most rapidly evolving viruses known. Analysis of codon usage can reveal much about the molecular evolution of the viruses. However, little information about synonymous codon usage pattern of polioviruses genome has been acquired to date.

Analysis of codon usage in Newcastle disease virus.

In this study, the relative synonymous codon usage (RSCU) values, effective number of codon (ENC) values, nucleotide contents, and dinucleotide were used to investigate codon usage pattern of each protein-coding gene and genome among 31 Newcastle disease virus (NDV) isolates. The result shows that the overall extent of codon usage bias in NDV is low (mean ENC = 56.15 > 40).