Engineered Trx2p industrial yeast strain protects glycolysis and fermentation proteins from oxidative carbonylation during biomass propagation

Gómez-Pastor Rocío, Pérez-Torrado Roberto, Cabiscol Elisa, Ros Joaquim, Matallana, Matallana Emilia

Description

In the yeast biomass production process, protein carbonylation has severe adverse effects since it diminishes biomass yield and profitability of industrial production plants. However, this significant detriment of yeast performance can be alleviated by increasing thioredoxins levels. Thioredoxins are important antioxidant defenses implicated in many functions in cells, and their primordial functions include scavenging of reactive oxygen species that produce dramatic and irreversible alterations such as protein carbonylation. Results In this work we have found several proteins specifically protected by yeast Thioredoxin 2 (Trx2p). Bidimensional electrophoresis and carbonylated protein identification from TRX -deficient and TRX -overexpressing cells revealed that glycolysis and fermentation-related proteins are specific targets of Trx2p protection. Indeed, the TRX2 overexpressing strain presented increased activity of the central carbon metabolism enzymes. Interestingly, Trx2p specifically preserved alcohol dehydrogenase I (Adh1p) from carbonylation, decreased oligomer aggregates and increased its enzymatic activity. Conclusions The identified proteins suggest that the fermentative capacity detriment observed under industrial conditions in T73 wine commercial strain results from the oxidative carbonylation of specific glycolytic and fermentation enzymes. Indeed, increased thioredoxin levels enhance the performance of key fermentation enzymes such as Adh1p, which consequently increases fermentative capacity.

Sujets

• Carbonylation
• Yeast
• Biomass
• Stress

Informations

• Publié par: biomed
• Publié le: 01 janvier 2012
• Nombre de lectures: 16
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

Gómez-Pastor et al . Microbial Cell Factories 2012, 11 :4 http://www.microbialcellfactories.com/content/11/1/4

R E S E A R C H Open Access Engineered Trx2p industrial yeast strain protects glycolysis and fermentation proteins from oxidative carbonylation during biomass propagation Rocío Gómez-Pastor 2 , Roberto Pérez-Torrado 2 , Elisa Cabiscol 3 , Joaquim Ros 3 and Emilia Matallana 1,2*

Abstract Background: In the yeast biomass production process, protein carbonylation has severe adverse effects since it diminishes biomass yield and profitability of industrial production plants. However, this significant detriment of yeast performance can be alleviated by increasing thioredoxins levels. Thioredoxins are important antioxidant defenses implicated in many functions in cells, and their primordial functions include scavenging of reactive oxygen species that produce dramatic and irreversible alterations such as protein carbonylation. Results: In this work we have found several proteins specifically protected by yeast Thioredoxin 2 (Trx2p). Bidimensional electrophoresis and carbonylated protein identification from TRX -deficient and TRX -overexpressing cells revealed that glycolysis and fermentation-related proteins are specific targets of Trx2p protection. Indeed, the TRX2 overexpressing strain presented increased activity of the central carbon metabolism enzymes. Interestingly, Trx2p specifically preserved alcohol dehydrogenase I (Adh1p) from carbonylation, decreased oligomer aggregates and increased its enzymatic activity. Conclusions: The identified proteins suggest that the fermentative capacity detriment observed under industrial conditions in T73 wine commercial strain results from the oxidative carbonylation of specific glycolytic and fermentation enzymes. Indeed, increased thioredoxin levels enhance the performance of key fermentation enzymes such as Adh1p, which consequently increases fermentative capacity. Keywords: Thioredoxins, Carbonylation, Yeasts, Biomass, Stress

Background the damage caused by ROS (reactive oxygen species) accu- In the industrial yeast biomass propagation process, oxida-  mulation [3]. Trx2p is part of the cytosolic TRX system tive stress plays an important role by decreasing biomass (thioredoxin1, thioredoxin 2, TRX reductase and NADPH) yield and affecting fermentative properties of the produced which reduces oxidized cysteine groups on proteins [4]. biomass [1,2]. Studying oxidative stress during the biomass Thioredoxins act as reducing agents of the oxidized form propagation process is essential to obtain stress-resistant of TRX peroxidase ( TSA1 ), then favoring the action of yeasts that are able to complete the industrial process with  reduced TRX peroxidase which scavenges ROS such as no detriment of their fermentative and growth properties.  H 2 O 2 [4]. Thioredoxins are involved in many cellular pro- Under industrial conditions, many cellular components cesses as a result of their oxidoreductase activity. They are negatively affected since lipid peroxidation increases, participate in sulphate metabolism by reducing PAPS while total glutathione and catalase activity decrease [3].  enzyme (3 ’ -phosphoadenosine 5 ’ -phosphosulphate reduc- However, TRX2 gene overexpression improves Saccharo-tase) [5] and maintaining the dNTP synthesis rate during myces cerevisiae oxidative stress response by diminishing the S-phase by acting as an electron donor of ribonucleo- tide reductase [6]. Thioredoxins are also involved in pro- tein folding, regulation of transcription factors [7] and 1 * D C e o p r a r r e t s a p m on e d nt e o nc d e e :e Bi m o il q ia u . í m mi a c t a all y an B a io @ l u o v g . í e a s Molecular,UniversitatdeValència, protein repair after oxidative damage [8]. Valencia, Spain Full list of author information is available at the end of the article © 2012 Gómez-Pastor et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.