Oligomerization of Friend spleen focus-forming virus (SFFV) env glycoproteins.

The glycoprotein gp55 and its processed form gp65, which are encoded by the env gene of Friend spleen focus-forming virus (SFFV), have been implicated in the initiation of the murine acute erythroleukemia induced by Friend virus (FV). Analyses of these glycoproteins by chemical crosslinking and nonreducing/reducing two-dimensional electrophoresis showed that both gp55 and gp65 exist as monomer and disulfide-bonded dimer and trimer. These oligomers could be detected in various FV-infected erythroleukemia cell lines, as well as in the spleen cells of FV-induced erythroleukemic mice, suggesting that oligomerization is an intrinsic feature of SFFV env glycoproteins.