Abstract: The Nonstructural 2 (NS2) protein plays an important role in the infection process of Classical Swine Fever Virus (CSFV), it is an autoprotease cleaving the NS2-3 polyprotein for the NS3 protein release. The NS2 protein is an easily biodegradable protein in cells and the biogradation pathways are not still very clear at present. The Swine Umbilical Vein Endothelial Cell (SUVEC) constucted by the lab is a good cell line model for studying the pathogenic mechanism of CSFV. In this study, the degradation of CSFV NS2 were observed by detecting the NS2 protein expression in SUVEC and PK-15 cells. The recombinant plasmid pEGFP-NS2 with complete NS2 gene of CSFV was transfected into SUVEC and PK-15 cells, respectively. The NS2 RNA was determined by RT-PCR and expression of NS2 protein in cells were analyzed by fluorescence microscopy and western blot assay after transfected. The degradation of NS2 protein also were observed by fluorescence microscopy and Western-blot assay. The results shown that the NS2 protein is short-lived in cells, the biodegradation process could be inhibited by a proteasomal inhibitor (MG132), hinting the NS2 protein is degraded via proteasome pathway in cells and this degradation process was related to the phosphorylation of NS2 protein. This is a primary study on the degradation of CSFV NS2 protein. The future experiments will address the degradation mechanism of CSFV NS2 and find the phosphorylation amino acids of NS2 protein which maybe relate to protein degadation in cells.
Kang-Kang Guo, Qing-Hai Tang, Peng-Bo Ning, He-Lin Li, Wei Liu, Qi-Zhuang Lv, Wu-Long Liang, Zhi Lin, Cheng-Cheng Zhang and Yan-Ming Zhang, 2013. Pilot Study on Degradation of Classical Swine Fever Virus Nonstructural 2 Protein in Cells. Journal of Animal and Veterinary Advances, 12: 234-241.