Table 1.
Proteins involved in the import of peroxisomal matrix proteins.
| Proteins | Functions and properties | Localization |
|---|---|---|
| Receptors | ||
| Pex5 | PTS1 receptor, contains C-terminal TPR domains | Cytosol/peroxisome |
| Pex7 | PTS2 receptor, contains WD domains | Cytosol/peroxisome |
| Pex20/Pex18/Pex21/Pex5L | PTS2 co-receptor, contains Pex7 binding box | Cytosol/peroxisome |
| Docking subcomplex | ||
| Pex14 | Component of the peroxisomal translocon | Integral PMP |
| Pex13 | Contains SH3 motif | Integral PMP |
| Pex17 | Associates with Pex14, no homolog in higher eukaryotes | Integral PMP |
| Pex33 | Contains an N-terminal domain homology to Pex14 | Integral PMP |
| Pex14/17 | Contains N-/C-terminal domain homology to Pex14 and Pex17 | Integral PMP |
| RING subcomplex | ||
| Pex2 | E3 ligase, receptor ubiquitination | Integral PMP |
| Pex10 | E3 ligase, receptor ubiquitination | Integral PMP |
| Pex12 | E3 ligase, receptor ubiquitination | Integral PMP |
| Receptor recycling machineries | ||
| Pex4/Ubc5H | Ubiquitin-conjugating enzyme, E2, for receptor mono-ubiquitination | Peripheral PMP |
| Pex22 | Peroxisomal anchor for Pex4 | Integral PMP |
| Pex1 | AAA ATPase for receptor recycling | Cytosol/PM |
| Pex6 | AAA ATPase for receptor recycling | Cytosol/PM |
| Pex15/Pex26 | Peroxisomal anchor for Pex6 | Integral PMP |
| Ubc4/5 | E2 for receptor poly-ubiquitination | Cytosol |
| Ubp15/USP9X | Deubiquitinase | Cytosol/peroxisome |
| AWP1 | Binds to Pex6 and mono-ubiquitinated Pex5 | Cytosol/peroxisome |
| Linker of the docking and RING subcomplexes | ||
| Pex8 | Contains a PTS1 and a PTS2, no homolog in higher eukaryotes | Peroxisome lumen |
| Pex3 | PMP receptor | Integral PMP |
PM: peroxisomal membrane; PMP: peroxisomal membrane protein.