The Intracellular Localization of the Proteasome
Proteasomes are large multiprotein complexes which constitute the main non-lysosomal (non-vacuolar in yeast) mechanism to degrade intracellular proteins. One major function of proteasomes is to degrade proteins that have been targeted for destruction by the ubiquitin pathway. By determining the levels of key regulatory proteins the proteasome plays a critical role in many different biological processes, such as cell cycle proliferation, development, apoptosis and antigen presentation (Hershko and Ciechanover 1998; Voges et al. 1999). The proteasome is also responsible for degrading other proteins independently of the ubiquitin pathway. Misfolded proteins and ornithine decarboxylase are examples of proteins that do not require the addition of a polyubiquitin signal for proteolysis by the proteasome to occur (Strickland et al. 2000; Coffino 2001).
KeywordsGreen Fluorescent Protein Fission Yeast Nuclear Periphery Green Fluorescent Protein Signal Ubiquitin Pathway
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