PhD defence Y.R. (Yvan) Campos Baquerizo

Summary:

Skeletal muscle development is a unique process that involves extensive biochemical and morphological changes. These require quality control mechanisms to regulate the abundance of structural and regulatory proteins that are essential for muscle differentiation. The ubiquitin proteasome system (UPS) is one of such mechanisms, which controls protein degradation in skeletal muscle. The ubiquitination reaction involves the covalent attachment of ubiquitin (Ub) or a ubiquitin chain to a target substrate by an enzymatic process consisting of an E1, Ub-activating enzyme, an E2, Ub-conjugating enzyme, and an E3 Ub ligase. The E3 ubiquitin ligases are the most numerous and diverse components of the ubiquitination machinery because they define the selectivity of the target substrates, as well as the sites on the substrate where the reaction occurs. Therefore, E3s must be tightly controlled to prevent spurious protein degradation. The study described in this thesis explored the properties and function of the Ub ligase complex, CRL5Ozz, and its substrate, Alix, in skeletal muscle.