A Protein-protein Interaction of Virus-host Visualized by the BiMC Assay Technique

The bimolecular complementation (BiMC) assay is a useful tool for a detection of protein-protein interaction, which locates in living cells and is able to be visualized under a fluorescent microscope. Cyclophilin A (CYPA) was found to be overexpressed in nasopharyngeal carcinoma in our previous study. The result also prompted us to explore the relationship between CYPA and Epstein-Barr virus nuclear antigen 1 (EBNA1). Here we identified their interaction by the BiMC assay. Plasmids expressing these two proteins fused with the C-or Y-terminus of YFP for this assay system were constructed firstly. After their co-transfection into 293T cells, specific nuclear fluorescence was observed. The results demonstrated that CYPA can bind to EBNA1, which deserved a further study of their functions.