Complete characterization of the gene coding for the Epstein-Barr virus major membrane antigen gp 220/340 and selective expression of a secreted form of gp 220

The gene which encodes the Epstein-Barr gp 220/340 was inserted into a eukaryotic expression vector. A cDNA clone corresponding to the mature mRNA coding for gp 220 was isolated from an Epstein-Barr virus cDNA library and inserted in the same expression vector, enabling us to identify the precise location of the intron within the gp 220/340 coding sequence. The recombinant plasmids direct the expression of membrane proteins detected by immunofluorescence experiments using an anti-gp 220/340 monoclonal antibody in transfected human cells. The region of the gp 220/340 gene encoding the domain for membrane anchorage was removed from the two recombinant plasmids and the sequence containing the intron produced secreted forms of both truncated gp 220 and gp 340 whereas only the former was obtained with the intronless sequence.