Protein Turnover

Ubiquitin is an abundant and essential cellular 9-kd protein that is conserved across evolution from yeast to humans. Ubiquitin is used by cells as a covalent modifier of other proteins both to activate their function and to target them for degradation, depending on the degree of ubiquitination.

Ubiquitin is a small, highly conserved protein which plays an important role in protein breakdown, covalently bonding to proteins to mark them for proteolytic degradation in a process called ubiquitination. Ubiquitin also binds to inclusion bodies (accumulations of protein) in pathological conditions such as Parkinson’s and Alzheimer's disease.