Stress-induced phospho-ubiquitin formation causes parkin degradation

Lyudmila Kovalchuke; Eugene V. Mosharov; Oren A. Levy; Lloyd A. Greene

. CC-BY-NC-ND 4.0 International license is made available under a The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. It . https://doi.org/10.1101/484857 doi: bioRxiv preprint WT: 33.5 ± 2.7% loss, C431S: 16.9 ± 1.8% loss, p = 0.002, N = 6; 12 hr: WT: 62.8 ± 1.7% loss, C431S: 31.7 ± 3.0% loss, p <0.0001, N = 4) (Fig. 8A ,C), consistent with the diminished phospho-poly-Ub signal observed in C431S-expressing cells relative to cells expressing exogenous wild-type parkin. In the case of hydrogen peroxide, C431S was modestly protected from peroxide-induced loss (WT: 49.1 ± 4.3% loss, C431S: 34.6 ± 3.2% loss, p = 0.06, N = 5), an effect that was less robust than that seen with CCCP. These results indicate that the extent to which parkin-mediated phospho-poly-Ub formation plays a role in parkin loss depends on the nature of the initiating stress.