Classification of genes identified in the screen by mechanism and effect on the regulated secretion of soluble cargo. S2 cells transfected with DE/AA GFP-/HA-dVMAT were treated with dsRNA-targeting genes identified in the screen, and the uptake of external HA antibody was measured as described in Fig. 1. (left) Representative cumulative frequency distributions are shown for selected genes in each class. Class I genes increase, class II genes decrease, and class III genes have no effect on antibody uptake by DE/AA dVMAT. (middle) S2 cells expressing ANF-GFP were treated with dsRNA and basal (unstimulated) secretion of GFP fluorescence determined as in Fig. 1 C. Secretion was normalized to cellular ANF-GFP and expressed as a percentage of the fluorescence secreted by control cells. (right) S2 cells expressing ANF-GFP were treated with dsRNA and LPS-induced secretion measured as in Fig. 1 D. *, P < 0.05; **, P < 0.01 (relative to control by two-tailed Student’s t test; n = 3–5). The data show mean values, and error bars indicate SEM.