Protein entrapment in PABPN1 aggregates was reported for other E3 ligases and the proteasome (Corbeil-Girard et al., 2005; Tavanez et al., 2005; Anvar et al., 2011), suggesting that the UPS machinery is dysregulated in OPMD. Here, PABPN1 is linked to oculopharyngeal muscular dystrophy.