LNX1 belongs to a family of multi-PDZ domain containing RING-type E3 ligases. Several interactions have been mapped to its PDZ domains, but the role of each domain in LNX function has not yet been determined. To study individual PDZ domain function in the context of full length protein I generated point mutations in peptide binding sites of each of PDZ domain, and in a putative phosphoinositide binding site of LNX1 PDZ4. Peptide binding was successfully disrupted by an arginine or lysine to alanine mutation in the peptide binding cleft. A LNX1 PDZ4 mutant with lysine residues in a putative phosphoinositide binding site mutated to glutamate displayed decreased membrane localization. The impact of each PDZ mutation on cell morphology and substrate ubiquitination was also investigated. I identified a potential role for PDZ binding in auto-inhibition of RING function. Additionally, novel interactions between LNX1 and Frizzled family members were identified and characterized.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/35136 |
| Date | 19 March 2013 |
| Creators | Prevost, Brittany |
| Contributors | McGlade, Jane |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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