20S proteasome biogenesis
2001; Elsevier BV; Volume: 83; Issue: 3-4 Linguagem: Inglês
10.1016/s0300-9084(01)01241-x
ISSN1638-6183
AutoresElke Krüger, Peter‐Michael Kloetzel, Cordula Enenkel,
Tópico(s)Peptidase Inhibition and Analysis
Resumo26S proteasomes are multi-subunit protease complexes responsible for the turnover of short-lived proteins. Proteasomal degradation starts with the autocatalytic maturation of the 20S core particle. Here, we summarize different models of proteasome assembly. 20S proteasomes are assembled as precursor complexes containing α and unprocessed β subunits. The propeptides of the β subunits are thought to prevent premature conversion of the precursor complexes into matured particles and are needed for efficient β subunit incorporation. The complex biogenesis is tightly regulated which requires additional components such as the maturation factor Ump1/POMP, an ubiquitous protein in eukaryotic cells. Ump1/POMP is associated with precursor intermediates and degraded upon final maturation. Mammalian proteasomes are localized all over the cell, while yeast proteasomes mainly localize to the nuclear envelope/endoplasmic reticulum (ER) membrane network. The major localization of yeast proteasomes may point to the subcellular place of proteasome biogenesis.
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