Date of Award

5-2016

Document Type

Thesis

Degree Name

Master of Science (MS)

Program

Biomedical Sciences

Track

Microbiology, Immunology, and Biochemistry

Research Advisor

Brenda A. Schulman, Ph.D.

Committee

Eric Enemark, Ph.D. Julio Cordero-Morales, Ph.D.

Abstract

RBR (RING1-in between RING-RING2) is a special type of E3 ubiquitin ligase containing three zinc-binding RING (Really Interesting New Gene) domains, while adopting mechanisms of HECT (Homologous to E6-AP Carboxyl Terminus) for substrate ubiquitination. Most well known RBRs include Parkin and HOIP, which are associated with Parkinson’s disease and innate immune deficiency. However, it is not well known how the RBR proteins gain activity, as they are known to be autoinhibited. Here I show that a specific F430A, E431A, E503A triple mutation of RBR protein HHARI (Human homologue of Ariadne) and its interaction with NEDD8ylated cullin RING ligase can both boost its activity and stabilize complex formation. Analytical size-exclusion chromatography, autoubiquitination, and electron microscopy reveal consistent behavior for this triple-mutant. Future structure-based studies will help elucidate the mechanism of the unsolved mystery of RBR activation and its interaction with NEDD8ylated cullin RING ligases.

ORCID

http://orcid.org/0000-0002-6853-4936

DOI

10.21007/etd.cghs.2016.0401

Available for download on Saturday, June 23, 2018

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