Fig. 6. Suppression of SNX2 or the joint suppression of SNX2 and SNX1 has no gross affect on EGF or transferrin receptor sorting. (A) HeLa cells were treated with either control, SNX2-specific siRNA or jointly with SNX1- and SNX2-specific siRNA duplexes for 72 hours. Cells were serum-starved for 3 hours and labelled with 1 kBq per well ¹²⁵I-EGF for 1 hour at 4°C, allowed to internalise surface bound ¹²⁵I-EGF for 5 minutes at 37°C, and then returned to 4°C. Cells were chased into 100 ng/ml cold EGF-containing media for various times at 37°C. Recycled, degraded and internalised fractions were subjected to gamma counting. Data is the average±s.d. from three independent experiments. (B) HeLa cells were treated with control, SNX2-specific siRNA or jointly with SNX1- and SNX2-specific siRNA duplexes for 72 hours. Cells were serum-starved for 3 hours and labelled with 1 kBq per well ¹²⁵I-transferrin for 60 minutes at 37°C. Cells were chased into 50 µg/ml cold transferrin-containing media for various times at 37°C. Recycled, degraded and internalised fractions were subjected to gamma counting. Data is the average±s.d. from three independent experiments. (C) Western analysis of a typical SNX1 and SNX2 suppression achieved during one of the three sets of receptor trafficking assays.