20S proteasome activity is modified via S-glutathionylation based on intracellular redox status of the yeast Saccharomyces cerevisiae: implications for the degradation of oxidized proteins.

Autor: Demasi M; Laboratório de Bioquímica e Biofísica, Instituto Butantan, Brazil. Electronic address: marimasi@butantan.gov.br., Hand A; Laboratório de Bioquímica e Biofísica, Instituto Butantan, Brazil., Ohara E; Laboratório de Bioquímica e Biofísica, Instituto Butantan, Brazil., Oliveira CL; Instituto de Física, Universidade de São Paulo, Brazil., Bicev RN; Instituto de Física, Universidade de São Paulo, Brazil., Bertoncini CA; Universidade Federal de São Paulo, Brazil., Netto LE; Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, Brazil.
Jazyk: angličtina
Zdroj: Archives of biochemistry and biophysics [Arch Biochem Biophys] 2014 Sep 01; Vol. 557, pp. 65-71. Date of Electronic Publication: 2014 May 09.
DOI: 10.1016/j.abb.2014.05.002
Abstrakt: Protein S-glutathionylation is a post-translational modification that controls many cellular pathways. Recently, we demonstrated that the α5-subunit of the 20S proteasome is S-glutathionylated in yeast cells grown to the stationary phase in rich medium containing glucose, stimulating 20S core gate opening and increasing the degradation of oxidized proteins. In the present study, we evaluated the correlation between proteasomal S-glutathionylation and the intracellular redox status. The redox status was controlled by growing yeast cells in distinct carbon sources which induced respiratory (glycerol/ethanol) or fermentative (glucose) metabolism. Cells grown under glycerol/ethanol displayed higher reductive power when compared to cells grown under glucose. When purified from cells grown in glucose, 20S proteasome α5-subunit exhibited an intense anti-glutathione labeling. A higher frequency of the open catalytic chamber gate was observed in the S-glutathionylated preparations as demonstrated by transmission electron microscopy. Therefore, cells that had been grown in glucose displayed an increased ability to degrade oxidized proteins. The results of the present study suggest that 20S proteasomal S-glutathionylation is a relevant adaptive response to oxidative stress that is capable to sense the intracellular redox environment, leading to the removal of oxidized proteins via a process that is not dependent upon ubiquitylation and ATP consumption.
(Copyright © 2014 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: