Biochemistry, Biophysics, and Structural Biology Commons^™

The Study Of The Structure And Dynamics Of Parkin Activation, Elaine Aisha Freeman

Electronic Thesis and Dissertation Repository

Parkin is an RBR E3 ubiquitin ligase that has been implicated in both sporadic and familial Parkinson’s disease. Upon mitochondrial damage, parkin is activated step-wise to recruit and ligate ubiquitin to a substrate on the outer mitochondrial membrane. Disruption of this activation and ligation cascade is hypothesized to result in neuronal death related to Parkinson’s disease.

While structures of parkin for a number of these activation states exist, it is important to note they are not of full-length human parkin. These structures are often truncated and come from various non-human species to eliminate important, yet hard to quantify structural elements. …

Autoinhibition And Activation Of Parkin, Jacob D. Aguirre

Electronic Thesis and Dissertation Repository

Mutations in the gene encoding parkin, an E3-ubiquitin ligase, result in 50% of Autosomal Recessive Juvenile Parkinsonism cases. Parkin has been identified as a key mediator of mitochondrial regeneration following oxidative stress, and pathogenic mutations have been shown to impair its ubiquitin ligase activity. Neurodegeneration of dopamine-producing neurons appears to be a downstream consequence of parkin loss-of-function, resulting in early-onset forms of Parkinson’s disease. Although ubiquitination activity is essential for its neuroprotective function, parkin is autoinhibited in its native state by various mechanisms, including its N-terminal ubiquitin-like (UBL) domain. Therefore, the overarching objective of this thesis was to structurally characterize …

Structure Of C-Terminal Domain Of Parkin, Ibr-Ring2, Yeong Ju Noh

Electronic Thesis and Dissertation Repository

Parkin is an E3 ubiquitin ligase which degrades misfolded proteins and prevents the formation of abnormal protein aggregates often formed in Parkinson’s disease. The main goal of this thesis was to perform structural analysis on the IBR(In-Between-RING)-RING2 (Really Interesting New Gene) domain of parkin. After determining the three-dimensional solution structure of the protein by NMR spectroscopy, the RING2 domain was identified to be similar to the IBR domain, showing that it is not a canonical RING domain. The catalytic cysteine on RING2 was also shown to be solvent exposed, supporting the recently proposed RING/HECT hybrid mechanism of parkin as an …

Structural Characterization Of Hip2 Enzyme Interactions In Ubiquitination, Benjamin W. Cook

Electronic Thesis and Dissertation Repository

The ubiquitin proteolysis pathway utilizes three enzymes, an E1 activating enzyme, an E2 conjugating enzyme and an E3 ligating enzyme, to respectively activate, transfer and ligate ubiquitin (Ub) onto a substrate protein. The creation of a K48-linked poly-Ub chain on a substrate will target this protein to be degraded by the 26S proteosome. E2 conjugating enzymes are central proteins in this pathway and interact with the E1 and E3 enzymes to perform Ub transfer. The mechanism by which Ub molecules are interconnected remains poorly understood. The E2 enzymes HIP2 and Ubc1 have been shown to create poly-Ub chains in the …