Fig. 3. The phosphomimicking mutant LIN-12(S/TtoD)::GFP. (A,B) LIN-12(S/TtoD)::GFP is downregulated normally in the 1° lineage. Enhanced internalization and increased accumulation in endocytic puncta (white arrowheads) and the basolateral plasma membrane (yellow arrowheads) is seen in the 2° lineage. (C,D) Loss of sur-2 activity prevents LIN-12(S/TtoD)::GFP downregulation in the 1° lineage and causes accumulation in the basolateral plasma membrane (yellow arrowheads). (E) Quantification of LIN-12(S/TtoD)::GFP downregulation. Scale bars: 10 µm.