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. The ubiquitin-proteasome pathway (UPP) is comprised of ubiquitin, a three-enzyme ubiquitination complex, the intracellular protein ubiquitination targets, and the proteasome that is the organelle for protein degradation (1).
WB analysis of ubiquitin in (Lane 1) poly-ubiquitin (lys63 linked), (Lane 2) pure ubiquitin and crude homogenates of adult rat, (Lane 3) cortex, (Lane 4) cerebellum and (Lane 5) brain stem.
Depending on the nature of the ubiquitin modification, the target protein may be destined for degradation or alternative nonproteolytic fates. Ubiquitin-mediated degradation of cellular proteins plays an important role in many basic cellular processes including the regulation of cell cycle and division, differentiation and development, cellular response to stress and extracellular effectors, morphogenesis of neuronal networks, modulation of cell-surface receptors, ion channels and the secretory pathways (2). The list of cellular proteins that are targeted by ubiquitin is a dynamic in nature and is rapidly growing; among them are cell cycle regulators, such as cyclins, cyclin-dependent kinase inhibitors, tumor suppressors, transcriptional activators and their inhibitors, cell-surface receptors and endoplasmic reticulum proteins. Finally, mutated and denatured/misfolded proteins are recognized specifically, and are removed efficiently by UPP suggesting that it is a key player in the cellular quality control and defense mechanisms (3). Novus Biologicals is the leading provider of ubiquitin related research reagents, providing world class antibodies and other tools for your research needs.
- PMID: 11917093
- PMID: 12653666
- PMID: 10872471
Novus Biologicals offers many Ubiquitin reagents, including: