Fig 1: Models of regulated endosomal recruitment of sorting nexins and retromer complexes. a The SNX3 protein typically associates weakly with membrane, and requires PI3P to bind stably. A fraction of free SNX3 can be phosphorylated at Ser72, which prevents membrane re-binding until dephosphorylation occurs to allow tight anchoring into the endosomal membrane and retromer recruitment. b Model of the retromer assembly on a membrane represented by DMPC bilayer, with the solution structure of SNX3 bound to PI3P (red, with green C-terminus) superimposed on the crystal structure of SNX3 (blue) and attached Vps26 (silver-green) and Vps35 (silver-red) structures7 depicted