The rubella virus E1 glycoprotein is arrested in a novel post-ER, pre- Golgi compartment

CHODG44 cells (2 x l0 s) were cotransfected with 20 #g pCMVS-E1 or pCMVS-E2E1 (20) and 2 #g pFR400 (57) using Lipofcctin (Bethesda Research Laboratories, Oaitherburg, MD). 2 d later cells were trypsinized and plated into MEM alpha containing 10% DFBS, penicillin, streptomycin, and glutamine. Media was changed every 4 d and colonies were picked after 12 to 14 d. Clones were expanded and screened for RV antigen by indirect immunofluorescence and radioimmunoprecipitation. Since adequate levels of expression were observed without methotrexate amplification, the amplification process was omiaed. CHO cells expressing RV E1 are referred to as CHOE1, whereas CHOE2E1 cells express both E2 and El.