Figure 5. Stability of Dpp and Dpp^ΔN in S2 cells.

(A) Stability of Dpp and Dpp^ΔN in a cell-free system. HA-Dpp and HA-Dpp^ΔN were incubated in M3 medium in the absence of S2 cells at 25°C. After the indicated times, HA-Dpp and HA-Dpp^ΔN were detected by western blot analysis using anti-HA antibody. The signal intensity at each incubation time relative to that of time 0 (shown as 1) was measured using the LI-COR Odyssey Blot system (LI-COR Biosciences) and is indicated as graphs on the right side. Relative levels of Dpp and Dpp^ΔN are shown by solid and dotted lines, respectively. The averaged values of results from three independent experiments are presented. (B and C) Degradation of Dpp and Dpp^ΔN in cell culture. HA-Dpp and HA-Dpp^ΔN were allowed to bind to S2 cells (B) or S2 cells overexpressing Dally (C) for 30 minutes at 25°C. After washing away unbound Dpp proteins and incubating cells for the indicated times at 25°C, the remaining proteins were detected from cell lysates as described above.