TRIMmunity and MAGE Interactions
Interferon (IFN)-β is involved in immune responses against viral infections. Some TRIM proteins, such as TRIM5 and TRIM22, are IFN-stimulated genes (ISGs) since their expression levels increases in response to IFNβ-intitiated signaling and, interestingly, have been shown to have direct and indirect antiviral activities, respectively. In a recent transciptomic analysis of polarized macrophages, we found that TRIM31 was specifically upregulated in response to INFβ treatment relative to the 32 additional activation conditions tested. We hypothesize that TRIM31 has antiviral activity, a role that may be dependent on formation of active E3 ubiquitin ligase complexes containing melanoma antigen gene (MAGE) proteins. We have initiated yeast-two hybrid-based experiments to confirm interactions between TRIM31 and three members of the MAGE family as well as to identify TRIM31 interaction partners. Co-localization studies will follow. The overall aim of our research program will be to characterize TRIM31 and other TRIM proteins to shed light on this family of proteins that has been subjected to strong, positive evolutionary pressure.