Regulation of AD-associated proteins by sorting nexins and the retromer complex. SNX6, SNX12, SNX17 and SNX27 regulate cell surface delivery of several AD-associated proteins, including APP, BACE1, glutamate receptors and LRP. SNX33 inhibits APP endocytosis in a dynamin-dependent manner. Over-expression of SNX33 up-regulates cell surface APP levels and increases α-secretase cleavage of APP. The retromer complex regulates APP processing and Aβ generation through modulating BACE1 trafficking and activity.