Chemical Synthesis of Structurally Defined Phosphorylated Ubiquitins Suggests Impaired Parkin Activation by Phosphorylated Ubiquitins with a Non-Phosphorylated Distal Unit

Mutations in genes encoding PINK1(PTEN-induced kinase 1)and Parkin(E3 ubiquitin ligase)are identified in familial Parkinson’s disease.However,it remains unclear whether the phosphorylated Ub chains activate wild-type Parkin(w-Parkin)or phosphorylated Parkin(p-Parkin),with the consequent expulsion of the damaged mitochondria.