Glutathiolation of the Proteasome Is Enhanced by Proteolytic Inhibitors

Demasi, Marilene; Shringarpure, Reshma; Davies, Kelvin J.A.

doi:10.1006/abbi.2001.2332

Cited by 77 publications

(75 citation statements)

References 30 publications

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“…1 and 2) and M. thermophila (Table II) to earlier results (15) obtained for mammalian 20 S proteasome, it is clear that the 20 S proteasome homologues respond differentially to changes in redox conditions. In this regard, it is important to observe that the mammalian counterpart has either long-or short-lived proteins as substrates, and its localization inside cells is widespread; it is found in the cytoplasm and nucleus (30).…”

Section: Discussionsupporting

confidence: 73%

“…This procedure was repeated twice, and the supernatants were combined. Total GSH, as well as GSSG, was assayed according to a protocol described previously (15). The determination was performed by reaction with DTNB in the presence of glutathione reductase and NADPH.…”

Section: Methodsmentioning

confidence: 99%

“…The Archaeon proteasome was not affected by GSH and was inhibited slightly by NEM (Table II). In the case of mammalian 20 S proteasome, both GSH and GSSG at micromolar concentrations activated the chymotrypsin-like activity, whereas it was inhibited by millimolar concentrations (15). Moreover, 20 S mammalian proteasomal activity was inhibited strongly by NEM.…”

Section: Table I Effect Of Cys-sh and Cys-soh Reactants On Proteasomamentioning

confidence: 95%

“…In a recent publication (15) it was demonstrated that the reduced and oxidized forms of GSH modulate the chymotrypsin-like activity of purified 20 S proteasome extracted from mammalian cells. In the present report we show that the activity of the 20 S proteasome purified from the yeast Saccharomyces cerevisiae is also sensitive to GSH, though in a different way from that observed in the mammalian proteasome.…”

mentioning

confidence: 99%

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20 S Proteasome from Saccharomyces cerevisiae Is Responsive to Redox Modifications and IsS-Glutathionylated

Demasi

Silva

Netto

2003

Journal of Biological Chemistry

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114

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Section: Discussionsupporting

confidence: 73%

Section: Methodsmentioning

confidence: 99%

Section: Table I Effect Of Cys-sh and Cys-soh Reactants On Proteasomamentioning

confidence: 95%

mentioning

confidence: 99%

See 2 more Smart Citations

20 S Proteasome from Saccharomyces cerevisiae Is Responsive to Redox Modifications and IsS-Glutathionylated

Demasi

Silva

Netto

2003

Journal of Biological Chemistry

Self Cite

114

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“…In fact, recent data suggests that the reversible S-glutathionylation of cysteine may be an important physiological regulator of the chymotrypsin-like activity (Demasi et al, 2001;Demasi et al, 2003). The current results further implicate the importance of cysteine residues for chymotrypsin-like activity by showing that the sulfhydryl-reactive compound NEM reduced degradation of both the LLVY peptide and the model substrate.…”

Section: Mechanisms Of Chymotrypsin-like Inhibitionsupporting

confidence: 73%

Age-dependent inhibition of proteasome chymotrypsin-like activity in the retina

Kapphahn

Bigelow

Ferrington

2007

Experimental Eye Research

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The proteasome plays a fundamental role in processes essential for cell viability. A loss in proteasome function has been associated with aging, as well as a number of age-related diseases. Defining the mechanism(s) behind this loss in function will add important information regarding the molecular basis for aging. In the current study, we performed an age-based comparison of proteasome function and composition of subunits and regulatory proteins in the neural retina and retinal pigment epithelium (RPE) in Fischer 344 rats. In the RPE, there was no age-dependent difference in activity, subunit composition, or content of proteasome regulators, PA28 and PA700. In contrast, the aged neural retina demonstrated a significant reduction in the chymotrypsin-like activity and decreased degradation of both casein and casein modified by 4-hydroxynonenal. This loss in function could not be explained by differences in subunit composition, content of PA28 and PA700, or reversible modification of cysteine residues. To begin investigating the molecular basis for the age-associated decrement in proteasome function, we modified the cysteine residues in proteasome from young rats with the sulfhydryl reactive chemical N-ethylmaleimide. We observed inhibition of the chymotrypsin-like activity and decreased degradation of casein that was comparable to that seen in aged retinas. Thus, chemical modification of cysteine provides an in vitro method that partially recapitulates aging proteasome. Further studies are required to confirm irreversible modification of functionally significant cysteine as a potential mechanism behind the age-related loss in proteasome function.

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Measurement of Protein Glutathionylation

Filipovska

Murphy

2006

CP Toxicology

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Proteins contain free, exposed thiols that can be glutathionylated in the native state as a result of thiol-disulfide exchange reactions with glutathione disulfide, catalyzed by glutaredoxin. A number of other reactions can also lead to protein glutathionylation. The modification of proteins by glutathionylation is important in oxidative damage and may be an important post-translational modification to proteins involved in redox signaling. This unit describes methods for the identification of glutathionylated proteins and quantification of the extent of glutathionylation. The protocols described use isolated mitochondrial protein complexes, mitochondrial membranes, and intact mitochondria, but can be easily adapted to other systems.

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Glutathiolation of the Proteasome Is Enhanced by Proteolytic Inhibitors

Cited by 77 publications

References 30 publications

20 S Proteasome from Saccharomyces cerevisiae Is Responsive to Redox Modifications and IsS-Glutathionylated

20 S Proteasome from Saccharomyces cerevisiae Is Responsive to Redox Modifications and IsS-Glutathionylated

Age-dependent inhibition of proteasome chymotrypsin-like activity in the retina

Measurement of Protein Glutathionylation

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