PROTEASOMES - DESTRUCTION AS A PROGRAM

Proteasomes are large multi-subunit protease complexes that selectivel y degrade intracellular proteins. Most of the proteins removed by thes e proteases are tagged for destruction by ubiquitination. Proteasomes have a role to play in controlling cellular processes, such as metabol ism and the cell cycle, through signal-mediated proteolysis of key enz ymes and regulatory proteins. They also operate in the stress response , by removing abnormal proteins, and in the immune response, by genera ting antigenic peptides.