Molecular Characterization of Porcine S100A6 Gene for its Antiviral Function Against PRRSV

In 2006, the highly-pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) spread to more than 10 Chinese provinces and affected over 2 million pigs with about 400,000 fatal cases.  Our previous study revealed that the S100A6 gene was significantly up-regulated in PAMs infected with HP-PRRSV.  In the present study, we cloned the promoter region of porcine S100A6 using a chromosome walking technique, and confirmed its promoter activity using Luciferase reporter assays. By analyzing the promoter region of porcine S100A6, we found two putative NF-κB binding sites. Transfect of p65 can induce the promoter activity of S100A6, while a NF-κB inhibitor, PDTC, can inhibit this activity.  As calcyclin binding protein (CACYBP) binds S100A6, we also investigated their co-expression patterns and cellular locations.  Reverse transcription-PCR revealed that both genes were expressed in 11 different tissues, and were highly expressed in lung, kidney and stomach of healthy animals. Transient transfection indicated that porcine S100A6 was located in the nucleus, while CACYBP was distributed in the whole cell.  Quantitative real-time PCR (Q-PCR) analysis further showed that the both porcine S100A6 and CACYBP genes were up-regulated in different cells and tissues of Tongcheng pigs infected with HP-PRRSV.  All these results provide a solid foundation to further investigate antiviral functions of S100A6 and its binding protein CACYBPagainst PRRSV. 

This study is supported by NSFC 31210103917.