Selective degradation of oxidatively modified protein substrates by the proteasome

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Abstract

Oxidative stress in mammalian cells is an inevitable consequence of their aerobic metabolism. Oxidants produce modifications to proteins leading to loss of function (or gain of undesirable function) and very often to an enhanced degradation of the oxidized proteins. For several years it has been known that the proteasome is involved in the degradation of oxidized proteins. This review summarizes our knowledge about the recognition of oxidized protein substrates by the proteasome in in vitro systems and its applicability to living cells. The majority of studies in the field agree that the degradation of mildly oxidized proteins is an important function of the proteasomal system. The major recognition motif of the substrates seems to be hydrophobic surface patches that are recognized by the 20S ‘core’ proteasome. Such hydrophobic surface patches are formed by partial unfolding and exposure of hydrophobic amino acid residues during oxidation. Oxidized proteins appear to be relatively poor substrates for ubiquitination, and the ubiquitination system does not seem to be involved in the recognition or targeting of oxidized proteins. Heavily oxidized proteins appear to first aggregate (new hydrophobic and ionic bonds) and then to form covalent cross-links that make them highly resistant to proteolysis. The inability to degrade extensively oxidized proteins may contribute to the accumulation of protein aggregates during diseases and the aging process.

Section snippets

Oxidative protein modification

The degree of protein oxidation caused by a given oxidant depends on many factors, including the nature, relative location, and flux rate of the oxidant, and the presence (or absence) of antioxidants. Both the oxidation of free amino acids and the oxidation of peptides and proteins have been studied by many laboratories, and numerous amino acids are known to be susceptible to oxidation [4], [5], [6], [11], [16], [18], [39], [40]. Although chemical reactions occur during amino acid side chain

Accumulation of cross-linked proteins

Several diseases, and aging processes, are accompanied by the accumulation of cross-linked proteins. This accumulation of oxidized protein aggregates can occur both extracellularly, and within various cellular compartments. Differences in the effects of protein aggregates on various cellular or organismal functions may be expected, depending on the rate of formation and the exact location of such aggregates. In several cases aggregated/cross-linked material will be autophagocytosed, resulting

Degradation of oxidized proteins

Following exposure to oxidants one can detect changes in the proteolytic susceptibility of a number of protein substrates (Fig. 2). This change in proteolytic susceptibility has a biphasic response. At moderate oxidant concentrations proteolytic susceptibility increases, whereas at higher oxidant concentrations a decrease (sometimes even below the ‘basal degradation’ level) in proteolytic susceptibility occurs (see Fig. 2). Between these extremes, the oxidant reaches an ‘optimal concentration’

Recognition of the oxidized protein substrates by the proteasome

It has been shown that erythrocytes and reticulocytes from rabbits, cows, and human beings, as well as rat muscles in vitro, rat hepatocytes, fibroblasts, macrophages, tumor cells, and Escherichia coli cells [1], [2], [9], [14], [15], [16], [21], [22], [24], [30], [31], [54], [55], [56], [57] are able to selectively degrade oxidatively modified proteins. What forms the recognition motif of oxidized proteins for the proteasome is one of the key research questions surrounding the fate of oxidized

Role of further components of the proteasomal system in the recognition of oxidized proteins

Numerous studies have been performed using the isolated 20S ‘core’ proteasome to degrade oxidized proteins. However, since our knowledge about the proteasomal system, its components, and its coordinated action with various ubiquitination systems is quite extensive, the question arises as to which form of the proteasome is involved in the degradation of oxidized proteins. Today it is accepted that the proteasome is just the core proteolytic particle of a whole system of regulatory factors, many

Recognition of oxidized proteins in cells

Although it is generally accepted that oxidized, unfolded proteins can be degraded by the isolated 20S ‘core’ proteasome in vitro, it has been rather less clear if this same form of the proteasome actually has physiological relevance in living cells. Rivett [1], [2] demonstrated the selective degradation of oxidatively modified glutamine synthetase in a non-lysosomal pathway by a cytosolic protease. Subsequently, numerous studies have demonstrated that this key enzyme is the proteasome,

References (100)

  • R.E. Pacifici et al.

    Macroxyproteinase (M.O.P.): a 670 kDa proteinase complex that degrades oxidatively denaturated proteins in red blood cells

    Free Radic. Biol. Med.

    (1989)
  • R.E. Pacifici et al.

    Protein degradation as an index of oxidative stress

    Methods Enzymol.

    (1990)
  • R.E. Pacifici et al.

    Hydrophobicity as the signal for selective degradation of hydroxyl radical-modified hemoglobin by the multicatalytic proteinase complex, proteasome

    J. Biol. Chem.

    (1993)
  • C. Giulivi et al.

    Dityrosine and tyrosine oxidation products are endogenous markers for the selective proteolysis of oxidatively modified red blood cell hemoglobin by (the 19S) proteasome

    J. Biol. Chem.

    (1993)
  • C. Giulivi et al.

    Exposure of hydrophobic moieties promotes the selective degradation of hydrogen peroxide-modified hemoglobin by the multicatalytic proteinase complex, proteasome

    Arch. Biochem. Biophys.

    (1994)
  • C. Giulivi et al.

    Dityrosine: a marker for oxidatively modified proteins and selective proteolysis

    Methods Enzymol.

    (1994)
  • R.L. Levine et al.

    Carbonyl assays for determination of oxidatively modified proteins

    Methods Enzymol.

    (1994)
  • T. Grune et al.

    Proteolysis in cultered liver epithelial cells during oxidative stress: role of the multicatalytic proteinase complex, proteasome

    J. Biol. Chem.

    (1995)
  • T. Grune et al.

    Degradation of oxidized proteins in K562 human hematopoietic cells by proteasome

    J. Biol. Chem.

    (1996)
  • T. Grune et al.

    Peroxynitrite increases the degradation of aconitase and other cellular proteins by proteasome

    J. Biol. Chem.

    (1998)
  • J. Jahngen-Hodge et al.

    Regulation of ubiquitin-conjugating enzymes by glutathione following oxidative stress

    J. Biol. Chem.

    (1997)
  • O. Ullrich et al.

    Influence of DNA binding on the degradation of oxidized histones by the 20S proteasome

    Arch. Biochem. Biophys.

    (1999)
  • J. Gieche et al.

    Protein oxidation and proteolysis in RAW264.7 macrophages: effects of PMA activation

    Biochim. Biophys. Acta

    (2001)
  • K. Merker et al.

    Proteolysis of oxidized proteins and cellular senescence

    Exp. Gerontol.

    (2000)
  • R.A. Dunlop et al.

    Recent developments in the intracellular degradation of oxidized proteins

    Free Radic. Biol. Med.

    (2002)
  • B. Friguet et al.

    Modification of glucose-6-phosphate dehydrogenase by 4-hydroxy-2-nonenal. Formation of cross-linked protein that inhibits the multicatalytic protease

    J. Biol. Chem.

    (1994)
  • B. Friguet et al.

    Inhibition of the multicatalytic proteinase (proteasome) by 4-hydroxy-2-nonenal cross-linked protein

    FEBS Lett.

    (1997)
  • A. Terman et al.

    Ceroid/lipofuscin formation in cultured human fibroblasts: the role of oxidative stress and lysosomal proteolysis

    Mech. Ageing Dev.

    (1998)
  • T.G. Mack et al.

    Tau levels with frontotemporal dementia-17 mutations have both altered expression levels and phosphorylation profiles in differentiated neuroblastoma cells

    Neuroscience

    (2001)
  • D. Yin

    Biochemical basis of lipofuscin, ceroid, and age pigment-like fluorophores

    Free Radic. Biol. Med.

    (1996)
  • O. Ullrich et al.

    Degradation of hypochlorite-damaged glucose-6-phosphate dehydrogenase by the 20S proteasome

    Free Radic. Biol. Med.

    (1999)
  • K.J.A. Davies et al.

    Oxidatively denatured proteins are degraded by an ATP-independent proteolytic pathway in Escherichia coli

    Free Radic. Biol. Med.

    (1988)
  • N. Sitte et al.

    Proteasome-dependent degradation of oxidized proteins in MRC-5 fibroblasts

    FEBS Lett.

    (1998)
  • P. Lasch et al.

    Hydrogen peroxide-induced structural alterations of RnaseA

    J. Biol. Chem.

    (2001)
  • R. Hough et al.

    Purification of two high molecular weight proteases from rabbit reticulocyte lysate

    J. Biol. Chem.

    (1987)
  • A. Ciechanover

    The ubiquitin–proteasome proteolytic pathway

    Cell

    (1994)
  • J.M. Peters

    Proteasomes: protein degradation machines of the cell

    TIBS

    (1994)
  • R. Shringarpure et al.

    Ubiquitin-conjugation is not required for the degradation of oxidized proteins by the proteasome

    J. Biol. Chem.

    (2003)
  • F. Shang et al.

    Activity of ubiquitin-dependent pathway in response to oxidative stress

    J. Biol. Chem.

    (1997)
  • A.J. Rivett

    Intracellular distribution of proteasomes

    Curr. Opin. Immunol.

    (1998)
  • A.F. Kisselev et al.

    Binding of hydrophobic peptides to several non-catalytic sites promotes peptide hydrolysis by all active sites of the 20S proteasomes. Evidence for peptide-induced channel opening in the alpha rings

    J. Biol. Chem.

    (2002)
  • J.M. Fagan et al.

    The ATP-independent pathway in red blood cells that degrades oxidant-damaged hemoglobin

    J. Biol. Chem.

    (1992)
  • J.M. Fagan et al.

    Red blood cells contain a pathway for the degradation of oxidant-damaged hemoglobin that does not require ATP or ubiquitin

    J. Biol. Chem.

    (1986)
  • D.C. Salo et al.

    Superoxide dismutase is preferentially degraded by a proteolytic system from red blood cells following oxidative modification by hydrogen peroxide

    Free Radic. Biol. Med.

    (1988)
  • A. Stolzing et al.

    Degradation of oxidized extracellular proteins by microglia

    Arch. Biochem. Biophys.

    (2002)
  • K.J.A. Davies et al.

    Protein damage and degradation by oxygen radicals. IV. Degradation of denatured protein

    J. Biol. Chem.

    (1987)
  • K.J.A. Davies

    Intracellular proteolytic systems may function as secondary antioxidant defenses: an hypothesis

    Free Radic. Biol. Med.

    (1986)
  • K. Okada et al.

    4-Hydroxy-2-nonenal-mediated impairment of intracellular proteolysis during oxidative stress. identification of proteasomes as target molecules

    J. Biol. Chem.

    (1999)
  • A.L. Bulteau et al.

    Proteasome inhibition in glyoxal-treated fibroblasts and resistance of glycated glucose-6-phosphate dehydrogenase to 20S proteasome degradation in vitro

    J. Biol. Chem.

    (2001)
  • T. Grune et al.

    Protein oxidation and proteolysis by the nonradical oxidants singlet oxygen or peroxynitrite

    Free Radic. Biol. Med.

    (2001)
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