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Full-Text Articles in Biochemistry
Modulating Parkin E3 Ubiquitin Ligase Activity Using Phospho-Ubiquitin Variants, Susanna George
Modulating Parkin E3 Ubiquitin Ligase Activity Using Phospho-Ubiquitin Variants, Susanna George
Electronic Thesis and Dissertation Repository
Parkin is a Parkinson’s disease-linked E3 ubiquitin (Ub) ligase that promotes mitophagy by ubiquitination of mitochondrial outer membrane proteins. Phosphorylation of Ub at Ser65 by the PTEN-induced putative kinase 1 activates parkin. The role of other Ub phosphorylation sites and the associated kinases remain unknown. We optimized genetic code expansion to produce pure site-specfically phosphorylated Ub (pUb) variants (pUbS7, pUbS12, pUbS20, pUbS65) and investigated their activity in a key neurodegenerative pathway. Purification of pUbS7 revealed a +3 frameshifted protein (Ub ∆7) that was successfully purified away from the pUb. Parkin was …
Parkin Misfolding, Dysfunction, And Degradation In Parkinson's Disease, Alexander S. Mccarton
Parkin Misfolding, Dysfunction, And Degradation In Parkinson's Disease, Alexander S. Mccarton
Electronic Thesis and Dissertation Repository
Mutations in the gene encoding parkin (PARK2) result in familial early onset forms of Parkinson’s disease (PD) based on the loss of parkin’s E3 ubiquitin ligase function. Protein misfolding is a common molecular feature of most neurodegenerative diseases, including PD. To test whether parkin misfolding also plays a role in the more common spontaneous PD, we established and functionally characterized a parkin yeast model. We found that oxidative and protein folding stress, parkin point mutations and truncations, and parkin’s interaction with the PD-associated kinase PINK1 profoundly alter parkin’s subcellular localization and toxicity. Notably, these conditions also induce parkin fragmentation, degradation, …