Evaluating Novel Viral‐Host Protein Interactions

Abstract

Recent studies have shown that some viruses are able to hijack the cell's ubiquitination processes. Ubiquitination is used to target proteins for degradation in the cell; it also has a responsibility in immune signaling. Viruses have been able to manipulate this system to halt immune signaling and to degrade antiviral proteins in the cell. By studying viral and host protein interactions, the virus’ mechanism of infection can be revealed, and creation of novel therapeutics can begin. We predict that the Lassa virus, West Nile virus, and Hepatitis C virus manipulate the process of ubiquitination; none of which have vaccines. Our lab has been working with proteins from each of these viruses to evaluate their interactions with host proteins that are involved with the ubiquitination process. The specific viral protein targets include Z-protein (Lassa), NS1 (West Nile), and NS5A (Hepatitis C). The host proteins are Elongin B and Elongin C, which are part of the Cullin-RING ligase complex. The cell signaling protein SOCS2 is used as a control, because it is an endogenous substrate recognition subunit that interacts with Elongin B and C. To test this hypothesis, we designed and constructed unique co-expression constructs for Elongin B, Elongin C, and our viral targets. Protein expression was conducted in Escherichia coli. We plan to isolate the complex while verifying viral-host protein interactions using affinity and size exclusion chromatography. This research will reveal to us if these viruses infect host cells by hijacking the ubiquitination process. If this is confirmed, continued experimental steps can be taken to start designing unique therapeutics against these viral infections.