Proteins were separated by SDS-PAGE using 10% polyacrylamide gels. Immunoblotting was performed as described previously [52] . Antiserum against Lassa virus GP-C/GP-2 was also described previously [32] . Polyclonal rabbit anti-ß-tubulin antibody was purchased from Abcam (UK), and monoclonal mouse anti-Flag antibody from Sigma-Aldrich. Secondary antibodies labeled with Alexa680 or IRDye800 were from Molecular Probes Invitrogen and Biomol, respectively, and were used for visualization and quantification of detected proteins using the Odyssey Infrared Imaging System (LI-COR Biosciences).