Molecular characterization and biological activity of bovine interferon-omega3
RESEARCH IN VETERINARY SCIENCE
Authors: An, Dong; Guo, Yongli; Bao, Jun; Luo, Xiuxin; Liu, Ying; Ma, Bo; Gao, Mingchun; Wang, Junwei
Abstract
Bovine interferon-omega3 (BoIFN-omega 3) gene was amplified from bovine liver genomic DNA, which encodes a 195-amino acid protein containing a 23-amino acid signal peptide. Analysis of the molecular characteristics revealed that BoIFN-omega 3 evolving from IFN-omega, contained four cysteine residues and five alpha helices, showing that BolFN-omega 3 presented the typical molecular characteristics of type I interferon. BolFN-omega 3 exhibited antiviral and antiproliferative activities, which exerted a protective effect against VSV in several mammalian cell lines, as well as against BEV, IBRV, and BVDV in MDBK cell. Moreover, BolFN-omega 3 was shown to be highly sensitive to trypsin, but remaining stable despite changes in pH and temperature. Additionally, BoIFN-w3 induced the transcription of Mx1, ISG15, and ISG56 genes, as well as the expression of Mx1 protein in a time-dependent manner. These findings will be useful to further study BoIFN-omega in host's defence against infectious diseases, particularly viral infections. Furthermore, results will facilitate further research on the bovine interferon family. (C) 2017 Elsevier Ltd. All rights reserved.
Biochemical Characterization of Respiratory Syncytial Virus RNA-Dependent RNA Polymerase Complex
ACS INFECTIOUS DISEASES
Authors: Balakrishnan, Anand; Price, Edmund; Luu, Catherine; Shaul, Jacob; Wartchow, Charles; Cantwell, John; Vo, Todd; DiDonato, Michael; Spraggon, Glen; Hekmat-Nejad, Mohammad
Abstract
RNA-dependent RNA polymerases (RdRPs) from nonsegmented negative strand (NNS) RNA viruses perform both mRNA transcription and genome replication, and these activities are regulated by their interactions with RNA and other accessory proteins within the ribonucleoprotein (RNP) complex. Detailed biochemical characterization of these enzymatic activities and their regulation is essential for understanding the life cycles of many pathogenic RNA viruses and for antiviral drug discovery. We developed biochemical and biophysical kinetic methods to study the RNA synthesis and RNA binding activities of respiratory syncytial virus (RSV) L/P RdRP. We determined that the intact L protein is essential for RdRP activity, and in truncated L protein constructs, RdRP activity is abrogated due to their deficiency in RNA template binding. These results are in agreement with the observation of an RNA template-binding tunnel at the interface of RdRP and capping domains in RSV and vesicular stomatitis virus (VSV) L protein cryo-EM structures. We also describe nonradiometric assays for measuring RNA binding and RNA polymerization activity of RSV RdRP, which are amenable to compound screening and profiling.