Figure 7.

The gene product of E8R is a membrane protein. In A hydrophobicity plots of the gene products of E8R and A18R with the use of the dense alignment surface method. The dotted line on the graphs indicates the loose and the upper uninterrupted line the strict cut-off for the determination of a putative transmembrane region. The amino acid sequence of the E8R gene is depicted under its respective “dense alignment surface” plot. The putative transmembrane domains are underlined and the peptide sequence used to raise antibodies is indicated with a hatched line above the sequence. In B HeLa cells were infected (I) or mock infected (U) for 3 h. and postnuclear supernatants were prepared. Equal amounts of protein were loaded onto a 12.5% SDS-PAGE, blotted onto polyvinylidene difluoride membrane and the E8R protein detected by enhanced chemiluminescence with the use of the peptide antibody. On the right side the positions of the 34-, 38-, and 54-kDa marker proteins are indicated. In C infected and transfected cells were lysed at 6 h postinfection and the lysate subjected to extraction with TX-114. A is the aqueous phase and D the detergent phase. E8R- and A18R-GFP refers to detection of the transfected GFP-tagged proteins with the use of anti-GFP antibodies, whereas E8R represents the untagged vv protein detected by anti-E8R. The A14L and H5R gene products serve as a control for a membrane (Salmons et al., 1997) and a soluble protein, respectively, and were detected with antibodies raised against the respective proteins.