Table 1. Post-translational modifications of the proteasomal subunits upon DNA damage induced by doxorubicin.
| Subunit | Control | doxorubicin |
|---|---|---|
| PSMA6 (α1) | Ub: Lys171 | |
| Ac: Ser2, Lys45, Lys104 | Ac: Ser2, Lys30, Lys45, Lys54 | |
| PSMA2 (α2) | Ub: Lys53, Lys64 | Ub: Lys53 |
| Ac: Ala2, Lys165 | Ac: Ala2, Lys165 | |
| PSMA4 (α3) | Ub: Lys195, Lys199 | |
| Ac: Lys127, Lys195 | Ac: Lys187, Lys195, Lys199 | |
| PSMA5 (α5) | Ub: Lys192, Lys196 | Ub: Lys196, Lys203 |
| P: Ser16 | P: Ser16, Thr55, Ser56, Thr213 or Thr219 | |
| PSMA1 (α6) | Ub: Lys115 | Ub: Lys30, Lys115, Lys189, Lys208 |
| Ac: Met1, Lys30, Lys39, Lys61 | Ac: Met1, Lys50, Lys115 | |
| P: Tyr6, Thr11 | ||
| PSMA3 (α7) | Ub: Lys52 | |
| P: Ser250 | P: Ser250; one of the four Serines (2-8) | |
| PSMB6 (β1) | Ac: Lys67 | |
| Ub: Lys67 | ||
| P: Thr56, Ser58, Thr59 | P: Thr56, Ser58, Thr59 | |
| PSMB7(β2) | Ac: Lys72, Lys249 | |
| Ub: Lys249 | Ub: Lys249 | |
| PSMB3 (β3) | Ac: Ser2, Lys77 | Ac: Ser2, Lys17 |
| Ub: Lys15, Lys17, Lys77 | ||
| PSMB5 (β5) | Ub: Lys91 | |
| PSMB1 (β6) | Ub: Lys94 | |
| PSMB4 (β7) | Ac: Lys201 | |
| Ub: Lys201 |
Proteasomal subunits from normal (control) and DNA damaged cells (doxorubicin) were separated by 2D electrophoresis and analysed by mass-spectrometry. The following modifications are shown: P – phosphorylation, Ub – ubiquitylation (shown in italic), Ac – acetylation. Novel unpublished modification sites are shown in bold.