FIGURE 6.

Role of PEX14 in the release of cargo proteins into the peroxisomal matrix. A newly synthesized cargo protein (CP) is recognized by PEX5 in the cytosol. This protein complex then docks at and becomes inserted into the peroxisomal DTM of which only PEX14 is shown for simplicity. The DTM component(s) providing the docking site for the PEX5-cargo protein complex have not been unambiguously identified yet. As discussed elsewhere, two strong candidates for this role are PEX13 (86) and PEX14 itself (87, 88). Note that PEX13 may also participate in the cargo-release step (66). The multiple interactions of PEX5 with the N-terminal domain of the several PEX14 molecules present in the DTM ultimately trigger the release of the cargo into the peroxisomal matrix.