The ubiquitin-proteasome field has experienced a breathtaking development from obscure origins in the late 1970s and early 1980s, through a maturing but a well circumscribed field in the 1990s, into a huge, and ever growing interdisciplinary area in the 2000s. Nearly 7% of all genes encoded by the human genome comprise elements of the ubiquitin-proteasome system (UPS), making it the most complex of all biochemical pathways. This complexity depends mostly on its hierarchical organization, where the 20S proteasome is the common machinery mediating total or partial degradation of practically any...