The 26S proteasome is a 2.4 MDa multifunctional ATP-dependent proteolytic c
omplex, which degrades the majority of cellular polypeptides by an unusual
enzyme mechanism. Several groups of proteasome inhibitors have been develop
ed and are now widely used as research tools to study the role of the ubiqu
itin-proteasome pathway in various cellular processes, and two inhibitors a
re now in clinical trials for treatment of multiple cancers and stroke. (C)
2001 Elsevier Science Ltd. All rights reserved.