MinireviewOxidized proteins: Intracellular distribution and recognition by the proteasome
Section snippets
Protein oxidation and distribution of oxidized proteins
Proteins are attacked by various oxidants and as the consequence a variety of amino acids is modified [8], [9], [10]. Besides the side chain modification also a cleavage of the polypeptide backbone might occur, resulting in the formation of smaller fragments [8], [9], [10]. Regardless of the large variety of amino acid derivatives formed under in vitro conditions in cellular systems the variety of protein oxidation products is even larger, since a secondary protein modification by oxidation
The proteasomal system and the distribution of its components
To maintain the cellular function and integrity it is required to have systems available that are able to recognize and degrade damaged or misfolded proteins in a fast and efficient way, in order to prevent their aggregation and cross-linking, e.g. the formation of lipofuscin [44], [45], [46]. Such an aggregate is insoluble, non-degradable and perhaps lethal for a cell from a certain degree of accumulation [46]. To prevent such accumulation of protein aggregates several protein-degrading
Intracellular localization of the degradation of oxidized proteins
Comparing the investigated distributions of damaged proteins after various oxidative stresses and the proteasomal distribution, it seems likely, that the cell is able to keep the nuclear protein pool free of damage, while the cytosolic proteins are accumulating oxidative markers. Whether this is the result of a limited protein oxidation in the nucleus, a very efficient degradation of the damaged nuclear proteins, due to the high proteasome content, or whether there are systems involved
Acknowledgments
The work of TG was supported by BMU, DFG SFB 575, DFG GK1033 and the Heinrich Heine University Research Foundation.
References (86)
- et al.
Exp. Gerontol.
(2004) - et al.
Biochim. Biophys. Acta
(2005) - et al.
Biochem. Biophys. Res. Commun.
(2003) - et al.
Mol. Aspects Med.
(2003) - et al.
Arch. Biochem. Biophys.
(1994) - et al.
J. Biol. Chem.
(2001) - et al.
Arch. Biochem. Biophys.
(1996) - et al.
J. Biol. Chem.
(2003) - et al.
Anal. Biochem.
(1999) - et al.
Exp. Gerontol.
(2000)