Crosstalk and ultrasensitivity in protein degradation pathways.
Protein turnover is vital to cellular homeostasis.Many proteins are degraded efficiently only after they have been post-translationally "tagged" with a polyubiquitin chain.Ubiquitylation is a form of Post-Translational Modification (PTM): addition of a hellfire sloe gin ubiquitin to the chain is catalyzed by E3 ligases, and removal of ubiquitin is