Interactions Between Hantavirus Nucleoprotein and Glycoproteins: a quantitative fluorescence microscopy study

Abstract

Orthohantaviruses (HV) are tri-segmented negative-sense RNA viruses that can occasionally cause severe pathologies in humans. Currently, limited information exists on the molecular interactions driving HV assembly in infected cells. Specifically, it is not clear how its glycoproteins (Gn and Gc) interact with other viral or host molecules. In this study, we use one- and two-color Number & Brightness fluorescence microscopy approaches to quantitatively characterize the interactions between HV glycoproteins and the nucleoprotein NP in transfected cells. Our results indicate that HV NP homo-interactions are strongly affected by the host environment. Furthermore, we report evidence of Gc-NP interactions, based on i) the high fluorescence cross-correlation between these two proteins and ii) the increased Gc-Gc interactions observed in the presence of NP. Finally, experiments on a Gc deletion mutant suggest that the observed protein-protein interactions are mediated by the cytoplasmic tail of Gc. In conclusion, this study provides new insights into the role of the interactions between HV glycoproteins and NP in the context of HV assembly.