FIGURE 4.

Silencing of class II Arfs does not alter other secretion through the constitutive pathway. A, HeLa-prME-DENV1 cells were incubated at the indicated temperatures or in the presence of BFA for 8 h. RSP secretion was assessed by Western blot, visualizing dengue E protein expression in supernatant (SN) and cell lysate (CL) with the 4E11 monoclonal antibody. B, HeLa-prME-DENV1 cells treated with either NT or class II Arfs siRNAs were fixed, permeabilized, and stained for E protein and the indicated cellular markers. Calreticulin, ERGIC53, and Golgin97 were used to label ER, ER-Golgi intermediate compartment (ERGIC), and Golgi apparatus, respectively. Cell nuclei were stained with DAPI. C, HeLa cells were co-transfected with a plasmid coding for secretive horseradish peroxidase (ss-HRP) and with the specified siRNAs. HeLa-prME-DENV1 cells were transfected with specified siRNAs. BFA was used as the positive control. Secretion of ss-HRP was assessed by measuring horseradish peroxidase activity in the supernatant. Data are presented as the percentage of ss-HRP secretion relative to NT. Results are shown as mean ± S.D. of triplicate measurements from one experiment representative of three others.