RT Journal Article SR Electronic(1) A1 Leymarie, Olivier A1 Meyer, Léa A1 Tafforeau, Lionel A1 Lotteau, Vincent A1 Costa, Bruno Da A1 Delmas, Bernard A1 Chevalier, Christophe A1 Le Goffic, RonanYR 2017 T1 Influenza virus protein PB1-F2 interacts with CALCOCO2 (NDP52) to modulate innate immune response JF Journal of General Virology, VO 98 IS 6 SP 1196 OP 1208 DO https://doi.org/10.1099/jgv.0.000782 PB Microbiology Society, SN 1465-2099, AB PB1-F2 is a viral protein encoded by influenza A viruses (IAVs). PB1-F2 is implicated in virulence by triggering immune cell apoptosis and enhancing inflammation. To obtain an insight into the molecular mechanisms of PB1-F2-mediated virulence, we used the yeast two-hybrid approach to find new PB1-F2 cellular interactors. This allowed us to identify calcium-binding and coiled-coil domain 2 (CALCOCO2, also known as NDP52) as a binding partner of PB1-F2. Binding of PB1-F2 to CALCOCO2 was confirmed by pull-down. Surface plasmon resonance binding experiments enabled us to estimate the dissociation constant (K d) of the two partners to be around 20 nM. Using bioinformatics tools, we designed a CALCOCO2 interaction map based on previous knowledge and showed a strong connection between this protein and the type I interferon production pathways and the I-κB kinase/NF-κB signalling pathway. NF-κB reporter assays in which CALCOCO2, MAVS and PB1-F2 were co-expressed showed a cooperation of these three proteins to increase the inflammatory response. By contrast, PB1-F2 inhibits the TBK1-dependent activation of an ISRE reporter plasmid. We also demonstrated that the signal transducer TRAF6 is implicated in the enhancement of NF-κB activity mediated by PB1-F2/CALCOCO2 binding. Altogether, this report provides evidence of an interaction link between PB1-F2 and human proteins, and allows a better understanding of the involvement of PB1-F2 in the pathologic process mediated by IAV., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/jgv.0.000782