(a) The cytoplasmic tails of selected proteins from the surface proteome analysis were fused to GFP and analyzed for binding of endogenous SNX27 and mCherry-tagged SNX27ΔPDZ in immunoprecipitation experiments (uncropped blots shown in Fig. S5) (b) Antibody uptake experiments with antibodies against endogenous CD97 and HA-tagged Glut1. After 1h incubation at 37°, internalized Glut1 and CD97co-localized extensively with endogenous VPS35 or GFP-SNX27 on vesicular structures. (c) Upper panel: Immunofluorescent staining of HA-tagged Glut1 full length and Myc-tagged Glut1 with a truncated PDZ binding motif (Glut1-ΔPDZ), lower panel: Colocalization analysis of HA-Glut1 and HA-Glut1ΔPDZ with the lysosomal marker LAMP1. The graph represents the mean of three independent experiments with 10 images each. (n=3, * indicates p<0.05, unpaired t-test; error bars = s.d., individual data points shown in statistics source data, scale bar = 10μm) (d) Uptake assay with radioactive glucose in SNX27 and VPS35 depleted cells. The graph represents the mean of four independent experiments done in quadruplicates. (n=4,* indicates p<0.05, unpaired t-test; error bars = s.e.m., individual data points shown in statistics source data)