Table 1.
PTMs identified in proteasome complexes
| PTM | Subunit | Site | Tissue | Technique | Biological Function | Reference |
|---|---|---|---|---|---|---|
| Phosphorylation | α2 | Y121 | CWSV1 | Mutagenesis | Trafficking | (5) |
| Phosphorylation | α2 | S198 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | α2 | T204 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | α2 | ND | HEK293 | 32P | Catalytic activity | (26) |
| Phosphorylation | α3 | T33 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | α3 | S75 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | α3 | S81 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | α3 | S153 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | α3 | Y156 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | α3 | S173 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | α3 | ND | HEK293 | 32P | Catalytic activity | (26) |
| Phosphorylation | α4 | T97 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | α4 | Y153 | HEK293 | 2DE, mutagenesis | Catalytic activity | (44) |
| Phosphorylation | α5 | S134 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | α5 | T219 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | α5 | T230 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | α7 | S13 | Liver | LC-MS/MS | ND | (46) |
| Phosphorylation | α7 | T186 | Liver | LC-MS/MS | ND | (46) |
| Phosphorylation | α7 | S250 | COS-7 | LC-MS/MS | 26S assembly | (7) |
| Phosphorylation | α7 | His | Molt-4 | 32P | NDP kinase | (74) |
| Phosphorylation | β1 | S157 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | β1 | T181 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | β2 | T273 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | β2 | S277 | Liver | LC-MS/MS | ND | (46) |
| Phosphorylation | β3 | Y85 | Liver | LC-MS/MS | ND | (46) |
| Phosphorylation | β3 | T86 | Liver | LC-MS/MS | ND | (46) |
| Phosphorylation | β3 | His | Molt-4 | 32P | ND | (74) |
| Phosphorylation | β4 | S39 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | β5 | T48 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | β5 | S192 | Liver | LC-MS/MS | ND | (46) |
| Phosphorylation | β5 | S204 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | β6 | T38 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | β6 | S48 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | β6 | S167 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | β6 | S169 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | β7 | S93 | Heart | LC-MS/MS | ND | (46) |
| Phosphorylation | Rpt5 | ND | Hela | 32P | Catalytic activity | (68) |
| Phosphorylation | Rpt6 | S120 | MDA 468 | 32P, mutagenesis | Catalytic activity | (76) |
| Phosphorylation | Rpt6 | ND | Heart | 32P | 26S assembly | (61) |
| Phosphorylation | 11S | ND | Reticulocyte | 32P | Catalytic activity | (43) |
| Acetylation | α1 | K102 | NS | LC-MS/MS | ND | (14) |
| Acetylation | α1 | K104 | NS | LC-MS/MS | ND | (14) |
| Acetylation | α2 | K70 | NS | LC-MS/MS | ND | (14) |
| Acetylation | α2 | K171 | NS | LC-MS/MS | ND | (14) |
| Acetylation | α3 | K127 | NS | LC-MS/MS | ND | (14) |
| Acetylation | α3 | K176 | NS | LC-MS/MS | ND | (14) |
| Acetylation | α3 | K238 | NS | LC-MS/MS | ND | (14) |
| Acetylation | α4 | K227 | NS | LC-MS/MS | ND | (14) |
| Acetylation | α7 | K57 | NS | LC-MS/MS | ND | (14) |
| Acetylation | α7 | K110 | NS | LC-MS/MS | ND | (14) |
| Acetylation | α7 | K206 | NS | LC-MS/MS | ND | (14) |
| Acetylation | α7 | K230 | NS | LC-MS/MS | ND | (14) |
| Acetylation | α7 | K238 | NS | LC-MS/MS | ND | (14) |
| Acetylation | β1i | K53 | NS | LC-MS/MS | ND | (14) |
| Acetylation | β1i | K109 | NS | LC-MS/MS | ND | (14) |
| Acetylation | β3 | K77 | NS | LC-MS/MS | ND | (14) |
| Acetylation | β4 | K68 | NS | LC-MS/MS | ND | (14) |
| Acetylation | β4 | K185 | NS | LC-MS/MS | ND | (14) |
| Acetylation | β6 | K204 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpt1 | K116 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpt1 | K422 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpt2 | K238 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpt3 | K397 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpt3 | K401 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpt3 | K258 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpt4 | K20 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpt4 | K72 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpt4 | K206 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpt6 | K222 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpn2 | K310 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpn5 | K221 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpn5 | K368 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpn5 | K448 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpn6 | K417 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpn8 | K204 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpn8 | K214 | NS | LC-MS/MS | ND | (14) |
| Acetylation | Rpn9 | K298 | NS | LC-MS/MS | ND | (14) |
| Acetylation | 11Sγ | K195 | NS | LC-MS/MS | ND | (14) |
| Oxidation | Rpt3 | ND | Heart | 2DE | Catalytic activity | (21) |
| Oxidation | Rpt5 | ND | Heart | 2DE | Catalytic activity | (21, 56) |
| HNE modification | α1 | ND | Heart | 2DE | Catalytic activity | (12) |
| HNE modification | α2 | ND | Heart | 2DE | Catalytic activity | (12) |
| HNE modification | α4 | ND | Heart | 2DE | Catalytic activity | (12) |
| Poly-ADP ribosylation | ND | ND | K562 | 14C-ADP ribose | Catalytic activity | (67) |
| O-GlcNAc modification | Rpt2 | ND | NRK | 2DE | Catalytic activity | (78) |
| Ubiquitination | α1 | K59 | MCF-7 | LC-MS/MS | ND | (20) |
| Ubiquitination | α6 | K115 | Hela | LC-MS/MS | ND | (48) |
| Ubiquitination | α6 | K208 | Hela | LC-MS/MS | ND | (48) |
| Ubiquitination | β3 | ND | C2C12 | 2DE | ND | (69) |
| Ubiquitination | Rpt2 | K237 | HEK293 | LC-MS/MS | ND | (47) |
| Ubiquitination | Rpn10 | K84 | Yeast | Mutagenesis | Substrate specificity | (35) |
| Glycosylation | β3 | ND | MDCK | LC-MS/MS | ND | (13) |
| Glycosylation | Rpt11 | N241 | MDCK | LC-MS/MS | ND | (13) |
| Sumoylation | β2 | ND | Hela | LC-MS/MS | ND | (65) |
| Sumoylation | Rpt2 | ND | Hela | LC-MS/MS | ND | (65) |
| Sumoylation | Rpn1 | ND | Hela | LC-MS/MS | ND | (65) |
| Sumoylation | Rpn2 | ND | Hela | LC-MS/MS | ND | (65) |
| Sumoylation | Rpn5 | ND | Hela | LC-MS/MS | ND | (65) |
| Sumoylation | Rpn8 | ND | Hela | LC-MS/MS | ND | (65) |
| Sumoylation | Rpn10 | ND | Hela | LC-MS/MS | ND | (65) |
| Sumoylation | Rpn12 | ND | Hela | LC-MS/MS | ND | (65) |
| Sumoylation | Rpt1 | ND | HEK293 | LC-MS/MS | ND | (31) |
| Sumoylation | Rpt6 | ND | HEK293 | LC-MS/MS | ND | (31) |
| Sumoylation | α3 | ND | Yeast | LC-MS/MS | ND | (51) |
| Sumoylation | Rpn1 | ND | Yeast | LC-MS/MS | ND | (51) |
| Sumoylation | Rpn7 | ND | Yeast | LC-MS/MS | ND | (51) |
| Sumoylation | Rpn12 | ND | Yeast | LC-MS/MS | ND | (51) |
| Nitrosylation | α2 | Y228 | Pituitary | MALDI/MS/MS | ND | (75) |
Post-translational modifications (PTMs) and the specific site (if known) on proteasome subunits in various tissues. The techniques used in the discovery of PTMs and the biological function (if known) are included. In summary, 10 distinct PTMs have been identified on proteasome subunits. From those studies in which site-specific information was obtained, there were 33 phosphorylation sites on 12 20S, 2 19S, and 1 11S subunits; 38 acetylation sites on 9 20S, 10 19S, and 1 11S subunit; 5 ubiquitination sites on 3 20S and 2 19S subunits; 1 glycosylation site on 1 19S subunit; and 1 nitrosylation site on 1 20S subunit.
LC-MS/MS, liquid chromatography-tandem mass spectometry; ND, not determined; 2DE, two-dimensional electrophoresis; NDP, nucleoside diphosphate; HNE, 4-hydroxy-2-nonenal; O-GlcNAc, O-linked N-acetylglucosamine; NS, not specified; NRK, normal rat kidney cells; MDCK, Madin-Darby canine kidney cells; MALDI, matrix-assisted laser desorption/ionization.