FIG. 5.

Oligomerization of TMD1,2. 293 cells were electroporated with the indicated CMV-based expression vectors and harvested 48 h posttransfection, and cell lysates were immunoprecipitated with an anti-Myc antibody (9E10, Santa Cruz). Immunoprecipitates (IP) and whole-cell lysates (WCL) from transfected cells were resolved on SDS-10% PAGE gels and visualized by Western blot with anti-LMP-1 antiserum as described previously (4) and in Materials and Methods. The introduced LMP-1 protein is shown above each blot, and arrows on the sides of the blots mark each protein's migration. (A) Immunoprecipitation of individually expressed proteins with anti-Myc antibody. (B) Coimmunoprecipitation of LMP-1myc with CΔ55 (LMP-1 deletion mutant lacking 55 amino acids from the C terminus, included as an LMP-1-interacting partner [positive control]), NΔ25 (LMP-1 deletion mutant lacking the cytoplasmic N terminus, included as a noninteracting control), or TMD1,2. (C) Coimmunoprecipitation of TMD1,2 with TMD1, 2Δ55mycHis (a C-terminally truncated TMD1,2 lacking 55 amino acids from the C terminus in pcDNA3.1/mycHis [Invitrogen]). TMD1,2 does not detectably interact with LMP-1 or with itself.