Table 1.
Key enzymes in the SUMO pathway.
| Category | Name | Molecular weights | Cellular location | Isoform preference | Function | State of SUMO pathway |
|---|---|---|---|---|---|---|
| SENPs | SENP1 | 73.5 kDa | Cytoplasm, nucleus | All SUMO | Maturation | SUMOylation |
| SENP2 | 67.8 kDa | Cytoplasm, nucleus | All SUMO | |||
| SENP5 | 86.7 kDa | Nucleus (almost) | All SUMO | |||
| SUMO E1 | SAE1 | 38.5 kDa | Nucleus (almost) | All SUMO | Activation | SUMOylation |
| SAE2 | 71.2 kDa | Cytoplasm, nucleus | ||||
| SUMO E2 | UBC9 | 18.0 kDa | Nucleus (almost) | All SUMO | Conjugation | SUMOylation |
| SUMO E3 | PIAS1 | 71.8 kDa | Nucleus (almost) | All SUMO | Ligation | SUMOylation |
| PIAS3 | 68.0 kDa | Cytoplasm, nucleus | ||||
| PIASy | 56.5 kDa | Nucleus | ||||
| RanBP2 | 358.2 kDa | Nucleus | ||||
| MAPL | 39.8 kDa | Mitochondrion | ||||
| Pc2/CBX4 | 61.4 kDa | Nucleus | ||||
| Smc5/6 | 128.8 kDa | Nucleus | ||||
| ZNF451 | 121.5 kDa | Nucleus | ||||
| Topors | 119.2 kDa | Nucleus | ||||
| ZIP3 | 33.6 kDa | Nucleus | ||||
| Rhes | 30.4 kDa | Cell membrane | ||||
| KAP1 | 18.2 kDa | Cytoskeleton | ||||
| NSE2 | 27.9 kDa | Nucleus | ||||
| *SLX5/STUbLs | 71.2 kDa | Nucleus | ||||
| *SIZ1 | 100.8 kDa | Cytoplasm, nucleus | ||||
| *SIZ2 | 81.2 kDa | Nucleus | ||||
| SENPS | SENP1 | 73.5 kDa | Cytoplasm, nucleus | All SUMO | Deconjugation | deSUMOylation |
| SENP2 | 67.8 kDa | Cytoplasm, nucleus | All SUMO | |||
| SENP3 | 65.0 kDa | Nucleus (almost) | SUMO2/3 | |||
| SENP5 | 86.7 kDa | Nucleus (almost) | SUMO2/3 | |||
| SENP6 | 126.1 kDa | Nucleus (almost) | SUMO2/3 | |||
| SENP7 | 119.7 kDa | Cytoplasm, nucleus# | SUMO2/3 |
*
Specific for yeast while the others are present in human.
#
In human cell, a majority of SENP7 was localized in nuclei whereas in mouse and rabbit cells, most SENP7 was distributed in the cytoplasm (27).