Figure 2.

Two different models explaining how SNX-BAR, SNX27, and retromer function together to mediate endosomal protein sorting

(A) The SNX-BAR-SNX27-retromer supercompex is recruited to membrane by phospholipid and membrane proteins containing SBM, PDZbm, or both motifs. Cargoes containing both SBM and PDZbm are most effective in recruiting the supercomplex as they contain multiple binding sites.

(B) SNX27 is first recruited to membrane by PDZbm-containing cargoes. Interaction with retromer further promotes the formation the retrieval sub-domain. SNX27 cargoes are handed over SNX-BAR-coated tubulovesicular carriers via the interaction between SNX27 and SNX1/SNX2. In both cases, the cargo-enriched tubulo-vesicular carriers are pinched off from endosomes and deliver to the plasma membrane with the aid of actin cytoskeleton and motor proteins.