ubiquitylaation
Ubiquitylation is a post-translational modification in which a small protein called ubiquitin is covalently attached to a substrate protein. This process is catalyzed by a cascade of enzymes, typically involving an E1 ubiquitin-activating enzyme, an E2 ubiquitin-conjugating enzyme, and an E3 ubiquitin ligase. The E3 ligase plays a crucial role in substrate specificity, dictating which proteins are ubiquitylated. Ubiquitin itself can be attached as a single molecule (monoubiquitylation) or as a chain of ubiquitin molecules (polyubiquitylation). The type of ubiquitin linkage within a polyubiquitin chain can also vary, leading to different downstream effects.
Ubiquitylation serves as a versatile molecular signal that regulates a wide array of cellular processes. Monoubiquitylation