Fig. 3.
S-Nitrosylation of parkin and Uch-L1 impairs UPS activity. Aberrant S-nitrosylation of parkin disrupts its ubiquitin E3 ligase activity. S-Nitrosylated Uch-L1 manifests decreased deubiquitinase activity and increased transnitrosylation activity. Aberrant protein S-nitrosylation eventually impairs the function of the UPS, contributing to the accumulation of misfolded and aggregated proteins.