Characterisation of the nucleic acid binding features of the PRRSV 7ap and its ability to induce antinuclear antibodies

Abstract

A short alternative open reading frame named ORF7a has recently been discovered within the nucleocapsid gene of the porcine reproductive and respiratory syndrome virus (PRRSV) genome. Proteins (7ap) translated from the ORF7a of two divergent strains -a type I and a type II -are able to completely reduce the motility of nucleic acids at relatively high molar charge ratios in gel retardation assays indicating strong dsDNA-and ssRNA-binding capability. Conserved RNAand DNA-binding properties suggest that nucleic acid binding is a functional property of the divergent 7aps, and not an arbitrary consequence of their net positive charge. Sera from Hu7ap-immunised pigs and mice did not react with Hu7ap or Hu7ap-GFP; however, antinuclear antibodies were detected in the sera of the immunised animals, suggesting an ability of Hu7ap to interact with or mimic autoantigenic macromolecules.

Nanopore-Based Direct RNA-Sequencing Reveals a High-Resolution Transcriptional Landscape of Porcine Reproductive and Respiratory Syndrome Virus

“…Of note, the emerging evidence indicated that a novel alternative open reading frame was discovered in XM-2020, with lower transcriptional levels, encoding a 37-amino acid peptide inside the coding region of the N gene, named ORF7a (Table S3). This finding was supported by another study, and further experimental strategies are needed to validate the functional relevance of this potential short peptide during PRRSV infection [32,33]. Although the authentic expression profiles of these N-terminal truncated ORFs and their potential functions remain unclear, they represent an additional level of transcriptome complexity and greatly expand our earlier knowledge of the coding capacity for PRRSV.…”

Cellular localisation of the proteins of region 3 of feline enteric coronavirus

“…The localisation of the protein in multiple cellular compartments and the presence of predicted DNA binding and activator domains indicate pleiotropic functions of 3a that most probably involve the reprogramming of the transcriptional regulation of the infected cells. Viral proteins with similar multiple (cytosolic and nuclear) localisations were identified in several different viruses (e. g. 7ap of PRRSV, X protein of hepatitis B virus, μ2 of reovirus T1L (Mbisa et al, 2000;Henkler et al, 2001;Ma et al, 2011;Olasz et al, 2016Olasz et al, , 2017aRivera-Serrano et al, 2017) with proven nucleic acid binding and/or transcription regulating capabilities. Acta Veterinaria Hungarica 66, 2018 Protein 3b was found to localise in the mitochondrion and the nucleolus (Fig.…”

Coding-complete sequence of a vaccine-derived recombinant porcine reproductive and respiratory syndrome virus strain isolated in Hungary

“…ORFs 2a to 4 code for the membrane-associated glycoproteins GP2, GP3, and GP4 and a nonglycosylated membrane polypeptide, protein E. ORFs 5 to 7 encode three major structural proteins. These are, respectively, the envelope glycoprotein GP5, the nonglycosylated membrane protein M, and the nucleocapsid protein N, while two alternative ORFs overlapping with ORF5 and ORF7 code for the ORF5a protein and the 7ap protein, respectively [2–5].…”