scholarly journals Comparative Proteomic Analysis of Tolerance and Adaptation of Ethanologenic Saccharomyces cerevisiae to Furfural, a Lignocellulosic Inhibitory Compound

2009 ◽  
Vol 75 (11) ◽  
pp. 3765-3776 ◽  
Author(s):  
Feng-Ming Lin ◽  
Bin Qiao ◽  
Ying-Jin Yuan

ABSTRACT The molecular mechanism involved in tolerance and adaptation of ethanologenic Saccharomyces cerevisiae to inhibitors (such as furfural, acetic acid, and phenol) represented in lignocellulosic hydrolysate is still unclear. Here, 18O-labeling-aided shotgun comparative proteome analysis was applied to study the global protein expression profiles of S. cerevisiae under conditions of treatment of furfural compared with furfural-free fermentation profiles. Proteins involved in glucose fermentation and/or the tricarboxylic acid cycle were upregulated in cells treated with furfural compared with the control cells, while proteins involved in glycerol biosynthesis were downregulated. Differential levels of expression of alcohol dehydrogenases were observed. On the other hand, the levels of NADH, NAD+, and NADH/NAD+ were reduced whereas the levels of ATP and ADP were increased. These observations indicate that central carbon metabolism, levels of alcohol dehydrogenases, and the redox balance may be related to tolerance of ethanologenic yeast for and adaptation to furfural. Furthermore, proteins involved in stress response, including the unfolded protein response, oxidative stress, osmotic and salt stress, DNA damage and nutrient starvation, were differentially expressed, a finding that was validated by quantitative real-time reverse transcription-PCR to further confirm that the general stress responses are essential for cellular defense against furfural. These insights into the response of yeast to the presence of furfural will benefit the design and development of inhibitor-tolerant ethanologenic yeast by metabolic engineering or synthetic biology.

2003 ◽  
Vol 2 (3) ◽  
pp. 599-608 ◽  
Author(s):  
Margarida Moreira dos Santos ◽  
Andreas Karoly Gombert ◽  
Bjarke Christensen ◽  
Lisbeth Olsson ◽  
Jens Nielsen

ABSTRACT A detailed characterization of the central metabolic network of Saccharomyces cerevisiae CEN.PK 113-7D was carried out during cometabolism of different mixtures of glucose and acetate, using aerobic C-limited chemostats in which one of these two substrates was labeled with 13C. To confirm the role of malic enzyme, an isogenic strain with the corresponding gene deleted was grown under the same conditions. The labeling patterns of proteinogenic amino acids were analyzed and used to estimate metabolic fluxes and/or make inferences about the in vivo activities of enzymes of the central carbon metabolism and amino acid biosynthesis. Malic enzyme flux increased linearly with increasing acetate fraction. During growth on a very-high-acetate fraction, the activity of malic enzyme satisfied the biosynthetic needs of pyruvate in the mitochondria, while in the cytosol pyruvate was supplied via pyruvate kinase. In several cases enzyme activities were unexpectedly detected, e.g., the glyoxylate shunt for a very-low-acetate fraction, phosphoenolpyruvate carboxykinase for an acetate fraction of 0.46 C-mol of acetate/C-mol of substrate, and glucose catabolism to CO2 via the tricarboxylic acid cycle for a very-high-acetate fraction. Cytoplasmic alanine aminotransferase activity was detected, and evidence was found that α-isopropylmalate synthase has two active forms in vivo, one mitochondrial and the other a short cytoplasmic form.


Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1047
Author(s):  
Giovanna Di Emidio ◽  
Stefano Falone ◽  
Paolo Giovanni Artini ◽  
Fernanda Amicarelli ◽  
Anna Maria D’Alessandro ◽  
...  

Mitochondria act as hubs of numerous metabolic pathways. Mitochondrial dysfunctions contribute to altering the redox balance and predispose to aging and metabolic alterations. The sirtuin family is composed of seven members and three of them, SIRT3-5, are housed in mitochondria. They catalyze NAD+-dependent deacylation and the ADP-ribosylation of mitochondrial proteins, thereby modulating gene expression and activities of enzymes involved in oxidative metabolism and stress responses. In this context, mitochondrial sirtuins (mtSIRTs) act in synergistic or antagonistic manners to protect from aging and aging-related metabolic abnormalities. In this review, we focus on the role of mtSIRTs in the biological competence of reproductive cells, organs, and embryos. Most studies are focused on SIRT3 in female reproduction, providing evidence that SIRT3 improves the competence of oocytes in humans and animal models. Moreover, SIRT3 protects oocytes, early embryos, and ovaries against stress conditions. The relationship between derangement of SIRT3 signaling and the imbalance of ROS and antioxidant defenses in testes has also been demonstrated. Very little is known about SIRT4 and SIRT5 functions in the reproductive system. The final goal of this work is to understand whether sirtuin-based signaling may be taken into account as potential targets for therapeutic applications in female and male infertility.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Qing Xia ◽  
Xiangtian Ling ◽  
Zhonghao Wang ◽  
Tao Shen ◽  
Minghao Chen ◽  
...  

Abstract Purpose and background Recently, we found that maximal medial rectus recession and lateral rectus resection in patients with complete lateral rectus paralysis resulted in a partial restoration of abduction. In an attempt to understand some of the mechanisms involved with this effect we examined gene expression profiles of lateral recti from these patients, with our focus being directed to genes related to myogenesis. Materials and methods Lateral recti resected from patients with complete lateral rectus paralysis and those from concomitant esotropia (controls) were collected. Differences in gene expression profiles between these two groups were examined using microarray analysis and quantitative Reverse-transcription PCR (qRT-PCR). Results A total of 3056 differentially expressed genes (DEGs) were identified between these two groups. Within the paralytic esotropia group, 2081 genes were up-regulated and 975 down-regulated. The results of RT-PCR revealed that PAX7, MYOG, PITX1, SIX1 and SIX4 showed higher levels of expression, while that of MYOD a lower level of expression within the paralytic esotropia group as compared with that in the control group (p < 0.05). Conclusion The decreased expression of MYOD in the paralytic esotropia group suggested that extraocular muscle satellite cell (EOMSCs) differentiation processes were inhibited. Whereas the high expression levels of PAX7, SIX1/4 and MYOG, suggested that the EOMSCs were showing an effective potential for differentiation. The stimulation resulting from muscle surgery may induce EOMSCs to differentiate and thus restore abduction function.


Planta ◽  
2021 ◽  
Vol 253 (5) ◽  
Author(s):  
Peilei Chen ◽  
Valentino Giarola ◽  
Dorothea Bartels

Abstract Main conclusion The cell wall protein CpWAK1 interacts with pectin, participates in decoding cell wall signals, and induces different downstream responses. Abstract Cell wall-associated protein kinases (WAKs) are transmembrane receptor kinases. In the desiccation-tolerant resurrection plant Craterostigma plantagineum, CpWAK1 has been shown to be involved in stress responses and cell expansion by forming a complex with the C. plantagineum glycine-rich protein1 (CpGRP1). This prompted us to extend the studies of WAK genes in C. plantagineum. The phylogenetic analyses of WAKs from C. plantagineum and from other species suggest that these genes have been duplicated after species divergence. Expression profiles indicate that CpWAKs are involved in various biological processes, including dehydration-induced responses and SA- and JA-related reactions to pathogens and wounding. CpWAK1 shows a high affinity for “egg-box” pectin structures. ELISA assays revealed that the binding of CpWAKs to pectins is modulated by CpGRP1 and it depends on the apoplastic pH. The formation of CpWAK multimers is the prerequisite for the CpWAK–pectin binding. Different pectin extracts lead to opposite trends of CpWAK–pectin binding in the presence of Ca2+ at pH 8. These observations demonstrate that CpWAKs can potentially discriminate and integrate cell wall signals generated by diverse stimuli, in concert with other elements, such as CpGRP1, pHapo, Ca2+[apo], and via the formation of CpWAK multimers.


Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 304
Author(s):  
Tatyana Savchenko ◽  
Konstantin Tikhonov

Oxidative stress is an integral component of various stress conditions in plants, and this fact largely determines the substantial overlap in physiological and molecular responses to biotic and abiotic environmental challenges. In this review, we discuss the alterations in central metabolism occurring in plants experiencing oxidative stress. To focus on the changes in metabolite profile associated with oxidative stress per se, we primarily analyzed the information generated in the studies based on the exogenous application of agents, inducing oxidative stress, and the analysis of mutants displaying altered oxidative stress response. Despite of the significant variation in oxidative stress responses among different plant species and tissues, the dynamic and transient character of stress-induced changes in metabolites, and the strong dependence of metabolic responses on the intensity of stress, specific characteristic changes in sugars, sugar derivatives, tricarboxylic acid cycle metabolites, and amino acids, associated with adaptation to oxidative stress have been detected. The presented analysis of the available data demonstrates the oxidative stress-induced redistribution of metabolic fluxes targeted at the enhancement of plant stress tolerance through the prevention of ROS accumulation, maintenance of the biosynthesis of indispensable metabolites, and production of protective compounds. This analysis provides a theoretical basis for the selection/generation of plants with improved tolerance to oxidative stress and the development of metabolic markers applicable in research and routine agricultural practice.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Fuyun Hou ◽  
Taifeng Du ◽  
Zhen Qin ◽  
Tao Xu ◽  
Aixian Li ◽  
...  

Abstract Background Sweetpotato (Ipomoea batatas (L.) Lam.) serves as an important food source for human beings. β-galactosidase (bgal) is a glycosyl hydrolase involved in cell wall modification, which plays essential roles in plant development and environmental stress adaptation. However, the function of bgal genes in sweetpotato remains unclear. Results In this study, 17 β-galactosidase genes (Ibbgal) were identified in sweetpotato, which were classified into seven subfamilies using interspecific phylogenetic and comparative analysis. The promoter regions of Ibbgals harbored several stress, hormone and light responsive cis-acting elements. Quantitative real-time PCR results displayed that Ibbgal genes had the distinct expression patterns across different tissues and varieties. Moreover, the expression profiles under various hormonal treatments, abiotic and biotic stresses were highly divergent in leaves and root. Conclusions Taken together, these findings suggested that Ibbgals might play an important role in plant development and stress responses, which provided evidences for further study of bgal function and sweetpotato breeding.


2020 ◽  
Vol 318 (3) ◽  
pp. G419-G427 ◽  
Author(s):  
Tatsuhide Nabeshima ◽  
Shin Hamada ◽  
Keiko Taguchi ◽  
Yu Tanaka ◽  
Ryotaro Matsumoto ◽  
...  

The activation of the Kelch-like ECH-associated protein 1 (Keap1)-NF-E2-related factor 2 (Nrf2) pathway contributes to cancer progression in addition to oxidative stress responses. Loss-of-function Keap1 mutations were reported to activate Nrf2, leading to cancer progression. We examined the effects of Keap1 deletion in a cholangiocarcinoma mouse model using a mutant K-ras/ p53 mouse. Introduction of the Keap1 deletion into liver-specific mutant K-ras/ p53 expression resulted in the formation of invasive cholangiocarcinoma. Comprehensive analyses of the gene expression profiles identified broad upregulation of Nrf2-target genes such as Nqo1 and Gstm1 in the Keap1-deleted mutant K-ras/ p53 expressing livers, accompanied by upregulation of cholangiocyte-related genes. Among these genes, the transcriptional factor Sox9 was highly expressed in the dysplastic bile duct. The Keap-Nrf2-Sox9 axis might serve as a novel therapeutic target for cholangiocarcinoma. NEW & NOTEWORTHY The Keap1-Nrf2 system has a wide variety of effects in addition to the oxidative stress response in cancer cells. Addition of the liver-specific Keap1 deletion to mice harboring mutant K-ras and p53 accelerated cholangiocarcinoma formation, together with the hallmarks of Nrf2 activation. This process involved the expansion of Sox9-positive cells, indicating increased differentiation toward the cholangiocyte phenotype.


Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 266
Author(s):  
Chiara Lanzillotta ◽  
Fabio Di Domenico

Down syndrome (DS) is the most common genomic disorder characterized by the increased incidence of developing early Alzheimer’s disease (AD). In DS, the triplication of genes on chromosome 21 is intimately associated with the increase of AD pathological hallmarks and with the development of brain redox imbalance and aberrant proteostasis. Increasing evidence has recently shown that oxidative stress (OS), associated with mitochondrial dysfunction and with the failure of antioxidant responses (e.g., SOD1 and Nrf2), is an early signature of DS, promoting protein oxidation and the formation of toxic protein aggregates. In turn, systems involved in the surveillance of protein synthesis/folding/degradation mechanisms, such as the integrated stress response (ISR), the unfolded stress response (UPR), and autophagy, are impaired in DS, thus exacerbating brain damage. A number of pre-clinical and clinical studies have been applied to the context of DS with the aim of rescuing redox balance and proteostasis by boosting the antioxidant response and/or inducing the mechanisms of protein re-folding and clearance, and at final of reducing cognitive decline. So far, such therapeutic approaches demonstrated their efficacy in reverting several aspects of DS phenotype in murine models, however, additional studies aimed to translate these approaches in clinical practice are still needed.


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