Arenavirus Stable Signal Peptide Is the Keystone Subunit for Glycoprotein Complex Organization

Bederka, Lydia H.; Bonhomme, Cyrille J.; Ling, Emily L.; Buchmeier, Michael J.

The GP1 subunit was immunoprecipitated using the 2.11-15 conformation-specific monoclonal antibody. The only samples to precipitate the cleaved GP2 subunit were the WT GPC, the in trans reconstituted GPC, and the HA SSP GPC (Fig. 6C, lanes 2, 4, and 6 ). None of the SSP single or double point mutant glycoprotein constructs allowed for glycoprotein subunit associations. In no sample did the GP1 immunoprecipitate SSP (Fig. 6C) . FALA GPC and YALL GPC samples did not result in GP2 subunit detection, indicating that mutations within the SSP affect proper glycoprotein complex association. For both the HA and the GP1 IP assays, we did not interpret GPC pulldown results as positive IP interactions, since the antibodies are capable of interacting with the nascent, full-length, uncleaved precursor glycoprotein.