Purification and characterization of proteasomes from Saccharomyces cerevisiae.

The proteasome plays a central role in eukaryotic cells since it is responsible for the degradation of specific proteins involved in a large range of cellular processes. Analysis of proteasome mechanisms of action, or in vitro reconstitution, or dissection of the complex biological pathways in which it partakes, requires a reliable source of pure active proteasome. Although the biologically relevant form of the proteasome is usually considered to be the 26S proteasome, this unit describes different methods for purification and study of both 26S and 20S proteasomes from Saccharomyces cerevisiae cells.