Fig. 2. Dephrin is cleaved at the N terminus and shows no alternative translation. (A) Western blots of embryonic lysate reveal a band around 75 kDa, the predicted size of Dephrin and a band at 52 kDa. (B,C) Mosaic clones were generated by injection of a UAS plasmid carrying a fusion of GFP to the N terminus (B, GFP-Dephrin) or the C terminus (C, Dephrin-GFP) of Dephrin. In embryonic cells expressing GFP-Dephrin, the GFP (green) is mainly localised in the cytoplasm, whereas Dephrin (red) accumulates at the membrane (B). The different subcellular localisation of the two parts of the fusion protein indicates a cleavage at the N terminus. In cells expressing Dephrin-GFP (C), the GFP always colocalizes with Dephrin (yellow). Clones were stained in the presence of detergent. (D) Schneider cells transfected with a Dephrin-GFP fusion express a protein of 100 kDa (75 kDa of Dephrin + 27 kDa of GFP) and a second band of 80 kDa (52 kDa of Dephrin + 27 kDa of GFP). Left lane, unfused GFP; right lane, Dephrin-GFP (E) Dephrin shows no alternative initiation of translation. Anti-GFP reveals only one band in extracts from Schneider cells transfected with a plasmid encoding the N terminus of Dephrin (aa1-210) fused to GFP.