Aasha Turner Rose Hills
The Substrate Recognition Mechanism of E3 Ubiquitin Ligase Doa10
Regulation of protein homeostasis is essential to many cellular and organellar functions. Endoplasmic reticulum (ER)-associated protein degradation (ERAD) is a group of protein quality control mechanisms highly conserved among eukaryotes. Doa10 is an integral ER membrane E3 ubiquitin ligase responsible for ubiquitination and degradation of misfolded and mistargeted proteins in the cell. While the function of Doa10 is well documented, its exact substrate binding mechanism is unknown. From my project, I aim to answer the following question: which amino acid residues on Doa10 are essential for substrate binding and subsequent degradation? After constructing Doa10 loss of substrate-binding-function mutants in the TEB4/Doa10 domain, I will utilize a fluorescence-based assay to quantitatively measure the mutant Doa10 protein-degradation activity. Overexpression of Doa10 orthologs and the accumulation of misfolded proteins are linked to neurodegenerative diseases and to tumorigenesis as seen in cancer proliferation. My project may have future implications in developing new medical therapies related to targeted protein degradation.