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

Treatment of CHOE1 cells with 25 mM nocodazole or 2 /~g/ml BFA, resulted in dispersion of the Golgi complex as evidenced by the drastic change in ot-mannosidase II distri- bution from the typical compact perinuclear staining (Fig. 7 B) to widely dispersed vesicular and diffuse cytoplasmic staining patterns (Fig. 7, D and F) , but the staining pattern of El was not altered significantly under these conditions (Fig. 7, A, C, and E) . In contrast, very little colocalization of ~-rnannosidase II and E1 was evident in nocodazole or BFA-treated cells (Fig. 7, C-F) . Treatment of CHOE1 cells with BFA for shorter time periods (5, 10, 15, 20 , and 30 rain) indicated that Man II does not pass through the tubular ele-ments (data not shown) before redistributing to the PER (14, 32) .