SGEF forms a ternary complex with Scribble and Dlg1. (A) Lysates from HEK293FT cells expressing GFP-Dlg1 and HA-Scribble in the presence or absence of myc-SGEF were immunoprecipitated using GFP antibodies (GFP-trap nanobodies). The precipitates were immunoblotted with anti-myc, anti-GFP, and anti-HA antibodies as indicated. (B) Endogenous Dlg1 was immunoprecipitated from Caco2 cell lysates and immunoblotted for Dlg1, SGEF, and Scribble. (C) Endogenous Dlg1 was immunoprecipitated from CTRL and SGEF KD MDCK cell lysates and immunoblotted for Dlg1, SGEF, and Scribble. (D) Lysates from HEK293FT cells expressing the indicated constructs were immunoprecipitated using GFP antibodies (GFP-trap nanobodies). The precipitates were immunoblotted with anti-GFP antibodies to detect the immunoprecipitated protein and with anti-myc and anti-HA to detect the interacting partners. (E) Summary of results from C. (F) Cartoon representation of the ternary complex between Scribble, SGEF, and Dlg1. DBM, Dlg binding motif; iPBM, internal PDZ-binding motif.