UC Riverside Undergraduate Research Journal

Influenza is one of the most prevalent viruses that has plagued millions worldwide. Every year health organizations encourage the public to get their flu vaccines to combat the flu season. Although the flu vaccines and medicines are widely available, it is estimated that flu viruses still cause 20,000-50,000 deaths every year. The two most common influenza virus strains are influenza A and B viruses, or IAV and IBV, respectively. It has been discovered that drug resistance develops very soon after a new drug is launched. It is highly demanded that anti-flu virus drugs with novel mechanisms be developed. Our lab has discovered that SUMOylation, a post-translational modification, is essential to the viral IAV and IBV life cycle. In this study, we have screened all the E3 ligases in the human genome to discover the SUMO E3 ligase responsible for the essential SUMOylation of IAV M1 protein using our Quantitative Fluorescence Energy Transfer(qFRET). We first determined the FRET spectrum of all E3 ligases with M1 protein and then quantified the FRET signals to provide a first-line examination of interactions. We then determined the E3-M1 interaction affinities, KD, to ensure the real interactions. We found the E3 ligase PIAS1 has the highest affinity to M1 among other E3s. By understanding the interaction affinity between IAV M1 protein with SUMOylation E3 ligase, we hope to block the interaction between the PIAS1-M1 for novel anti-flu medicine development.