scholarly journals The LysR-type transcriptional regulator BsrA (PA2121) controls vital metabolic pathways in Pseudomonas aeruginosa

2021 ◽  
Author(s):  
Magdalena Modrzejewska ◽  
Adam Kawalek ◽  
Aneta A. Bartosik
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Stress Responses ◽  
Metabolic Pathways ◽  
Tricarboxylic Acid Cycle ◽  
Transcriptional Regulator ◽  
Negative Regulator ◽  
Transport Systems ◽  
Promoter Regions ◽  
Altered Expression ◽  
Intergenic Regions

Pseudomonas aeruginosa, a facultative human pathogen causing nosocomial infections, has complex regulatory systems involving many transcriptional regulators. LTTR (LysR-Type Transcriptional Regulator) family proteins are involved in the regulation of various processes including stress responses, motility, virulence and amino acid metabolism. The aim of this study was to characterize the LysR-type protein BsrA (PA2121), previously described as a negative regulator of biofilm formation in P. aeruginosa. Genome wide identification of BsrA binding sites using ChIP-seq revealed 765 BsrA-bound regions in the P. aeruginosa PAO1161 genome, including 367 sites in intergenic regions. The motif T-N11-A was identified within sequences bound by BsrA. Transcriptomic analysis showed altered expression of 157 genes in response to BsrA excess, of which 35 had a BsrA binding site within their promoter regions, suggesting a direct influence of BsrA on the transcription of these genes. BsrA-repressed loci included genes encoding proteins engaged in key metabolic pathways such as the tricarboxylic acid cycle. The panel of loci possibly directly activated by BsrA, included genes involved in pili/fimbriae assembly as well as secretion and transport systems. In addition, DNA pull-down and regulatory analyses showed the involvement of PA2551, PA3398 and PA5189 in regulation of bsrA expression, indicating that this gene is part of an intricate regulatory network. Taken together, these findings reveal the existence of a BsrA regulon, which performs important functions in P. aeruginosa.

scholarly journals The LysR-Type Transcriptional Regulator BsrA (PA2121) Controls Vital Metabolic Pathways in Pseudomonas aeruginosa

mSystems ◽  
2021 ◽  
Author(s):  
Magdalena Modrzejewska ◽  
Adam Kawalek ◽  
Aneta Agnieszka Bartosik
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Regulatory Network ◽  
Metabolic Pathways ◽  
Tricarboxylic Acid Cycle ◽  
Transcriptional Regulator ◽  
Tricarboxylic Acid ◽  
Content Type ◽  
Acid Cycle

This study shows that BsrA, a LysR-type transcriptional regulator from Pseudomonas aeruginosa , previously identified as a repressor of biofilm synthesis, is part of an intricate global regulatory network. BsrA acts directly and/or indirectly as the repressor and/or activator of genes from vital metabolic pathways (e.g., pyruvate, acetate, and tricarboxylic acid cycle) and is involved in control of transport functions and the formation of surface appendages.

scholarly journals Cross-Tolerance and Autoimmunity as Missing Links in Abiotic and Biotic Stress Responses in Plants: A Perspective toward Secondary Metabolic Engineering

2021 ◽  
Vol 22 (21) ◽  
pp. 11945
Author(s):  
Lakshmipriya Perincherry ◽  
Łukasz Stępień ◽  
Soniya Eppurathu Vasudevan
Keyword(s):  
Stress Responses ◽  
Metabolic Pathways ◽  
Abiotic And Biotic Stress ◽  
Cross Tolerance ◽  
Biotic And Abiotic Stresses ◽  
Altered Expression ◽  
Protective Autoimmunity ◽  
Genes Expression ◽  
Mrna Surveillance ◽  
The Common

Plants employ a diversified array of defense activities when they encounter stress. Continuous activation of defense pathways that were induced by mutation or altered expression of disease resistance genes and mRNA surveillance mechanisms develop abnormal phenotypes. These plants show continuous defense genes’ expression, reduced growth, and also manifest tissue damage by apoptosis. These macroscopic abrasions appear even in the absence of the pathogen and can be attributed to a condition known as autoimmunity. The question is whether it is possible to develop an autoimmune mutant that does not fetch yield and growth penalty and provides enhanced protection against various biotic and abiotic stresses via secondary metabolic pathways’ engineering. This review is a discussion about the common stress-fighting mechanisms, how the concept of cross-tolerance instigates propitious or protective autoimmunity, and how it can be achieved by engineering secondary metabolic pathways.

scholarly journals Characteristics of SlCML39, a Tomato Calmodulin-like Gene, and Its Negative Role in High Temperature Tolerance of Arabidopsis thaliana during Germination and Seedling Growth

2021 ◽  
Vol 22 (21) ◽  
pp. 11479
Author(s):  
Haidong Ding ◽  
Ying Qian ◽  
Yifang Fang ◽  
Yurong Ji ◽  
Jiarong Sheng ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
High Temperature ◽  
Seedling Growth ◽  
Stress Responses ◽  
Plant Stress ◽  
Temperature Tolerance ◽  
Signal Pathway ◽  
Negative Regulator ◽  
Growth Stages ◽  
Promoter Regions

Calmodulin-like (CML) proteins are primary calcium sensors and function in plant growth and response to stress stimuli. However, so far, the function of plant CML proteins, including tomato, is still unclear. Previously, it was found that a tomato (Solanum lycopersicum) CML, here named SlCML39, was significantly induced by high temperature (HT) at transcription level, but its biological function is scarce. In this study, the characteristics of SlCML39 and its role in HT tolerance were studied. SlCML39 encodes a protein of 201 amino acids containing four EF hand motifs. Many cis-acting elements related to plant stress and hormone response appear in the promoter regions of SlCML39. SlCML39 is mainly expressed in the root, stem, and leaf and can be regulated by HT, cold, drought, and salt stresses as well as ABA and H2O2. Furthermore, heterologous overexpression of SlCML39 reduces HT tolerance in Arabidopsis thaliana at the germination and seedling growth stages. To better understand the molecular mechanism of SlCML39, the downstream gene network regulated by SlCML39 under HT was analyzed by RNA-Seq. Interestingly, we found that many genes involved in stress responses as well as ABA signal pathway are down-regulated in the transgenic seedlings under HT stress, such as KIN1, RD29B, RD26, and MAP3K18. Collectively, these data indicate that SlCML39 acts as an important negative regulator in response to HT stress, which might be mediated by the ABA signal pathway.

scholarly journals The AraC-Type Transcriptional Regulator GliR (PA3027) Activates Genes of Glycerolipid Metabolism in Pseudomonas aeruginosa

2021 ◽  
Vol 22 (10) ◽  
pp. 5066
Author(s):  
Karolina Kotecka ◽  
Adam Kawalek ◽  
Kamil Kobylecki ◽  
Aneta Agnieszka Bartosik
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Transcriptional Profiling ◽  
Transcriptional Regulator ◽  
Promoter Sequence ◽  
Large Set ◽  
Mrna Levels ◽  
Cellular Functions ◽  
Promoter Regions ◽  
Genes Encoding

Pseudomonas aeruginosa encodes a large set of transcriptional regulators (TRs) that modulate and manage cellular metabolism to survive in variable environmental conditions including that of the human body. The AraC family regulators are an abundant group of TRs in bacteria, mostly acting as gene expression activators, controlling diverse cellular functions (e.g., carbon metabolism, stress response, and virulence). The PA3027 protein from P. aeruginosa has been classified in silico as a putative AraC-type TR. Transcriptional profiling of P. aeruginosa PAO1161 overexpressing PA3027 revealed a spectacular increase in the mRNA levels of PA3026-PA3024 (divergent to PA3027), PA3464, and PA3342 genes encoding proteins potentially involved in glycerolipid metabolism. Concomitantly, chromatin immunoprecipitation-sequencing (ChIP-seq) analysis revealed that at least 22 regions are bound by PA3027 in the PAO1161 genome. These encompass promoter regions of PA3026, PA3464, and PA3342, showing the major increase in expression in response to PA3027 excess. In Vitro DNA binding assay confirmed interactions of PA3027 with these regions. Furthermore, promoter-reporter assays in a heterologous host showed the PA3027-dependent activation of the promoter of the PA3026-PA3024 operon. Two motifs representing the preferred binding sites for PA3027, one localized upstream and one overlapping with the −35 promoter sequence, were identified in PA3026p and our data indicate that both motifs are required for full activation of this promoter by PA3027. Overall, the presented data show that PA3027 acts as a transcriptional regulator in P. aeruginosa, activating genes likely engaged in glycerolipid metabolism. The GliR name, from a glycerolipid metabolism regulator, is proposed for PA3027 of P. aeruginosa.

scholarly journals Direct and Indirect Control of Late Sporulation Genes by GerR of Bacillus subtilis

2010 ◽  
Vol 192 (13) ◽  
pp. 3406-3413 ◽  
Author(s):  
Giuseppina Cangiano ◽  
Antonio Mazzone ◽  
Loredana Baccigalupi ◽  
Rachele Isticato ◽  
Patrick Eichenberger ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Rna Polymerase ◽  
Chromatin Immunoprecipitation ◽  
Transcriptional Regulator ◽  
Transcriptional Factor ◽  
Negative Regulator ◽  
Promoter Regions ◽  
Indirect Control ◽  
Sporulation Genes

ABSTRACT GerR is a sporulation-specific transcriptional factor of Bacillus subtilis that has been identified as a negative regulator of genes transcribed by σE-containing RNA polymerase and as a positive effector of the expression of three late sporulation genes. Here we confirmed that gerR transcription is dependent on σE-containing RNA polymerase but also observed that it requires the transcriptional regulator SpoIIID. The study of the role of GerR in regulating the expression of several late sporulation genes allowed us to observe that its effect is strongly positive on spoVIF, cotC, and cotG, weakly positive on cotB, and negative on cotU. The results of chromatin immunoprecipitation (ChIP) experiments indicated that GerR binds to the promoter regions of some, but not all, of the GerR-controlled genes, leading us to propose that GerR controls late sporulation genes in two ways: (i) directly, by acting on the transcription of cotB, cotU and spoVIF; and (ii) indirectly, through the activation of SpoVIF, which stabilizes the transcriptional activator GerE and consequently induces the expression of the GerE-dependent genes cotC and cotG.

scholarly journals Transcription of Sialic Acid Catabolism Genes in Corynebacterium glutamicum Is Subject to Catabolite Repression and Control by the Transcriptional Repressor NanR

2016 ◽  
Vol 198 (16) ◽  
pp. 2204-2218 ◽  
Author(s):  
Andreas Uhde ◽  
Natalie Brühl ◽  
Oliver Goldbeck ◽  
Christian Matano ◽  
Oksana Gurow ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Corynebacterium Glutamicum ◽  
Reporter Gene ◽  
Catabolite Repression ◽  
Transcriptional Regulator ◽  
Promoter Regions ◽  
Content Type ◽  
Acetylneuraminic Acid ◽  
Expression Of Genes ◽  
Intergenic Regions

ABSTRACTCorynebacterium glutamicummetabolizes sialic acid (Neu5Ac) to fructose-6-phosphate (fructose-6P) via the consecutive activity of the sialic acid importer SiaEFGI,N-acetylneuraminic acid lyase (NanA),N-acetylmannosamine kinase (NanK),N-acetylmannosamine-6P epimerase (NanE),N-acetylglucosamine-6P deacetylase (NagA), and glucosamine-6P deaminase (NagB). Within the cluster of the three operonsnagAB,nanAKE, andsiaEFGIfor Neu5Ac utilization a fourth operon is present, which comprisescg2936, encoding a GntR-type transcriptional regulator, here named NanR. Microarray studies and reporter gene assays showed thatnagAB,nanAKE,siaEFGI, andnanRare repressed in wild-type (WT)C. glutamicumbut highly induced in a ΔnanR C. glutamicummutant. Purified NanR was found to specifically bind to the nucleotide motifs A[AC]G[CT][AC]TGATGTC[AT][TG]ATGT[AC]TA located within thenagA-nanAandnanR-sialAintergenic regions. Binding of NanR to promoter regions was abolished in the presence of the Neu5Ac metabolism intermediates GlcNAc-6P andN-acetylmannosamine-6-phosphate (ManNAc-6P). We observed consecutive utilization of glucose and Neu5Ac as well as fructose and Neu5Ac by WTC. glutamicum, whereas the deletion mutantC. glutamicumΔnanRsimultaneously consumed these sugars. Increased reporter gene activities fornagAB,nanAKE, andnanRwere observed in cultivations of WTC. glutamicumwith Neu5Ac as the sole substrate compared to cultivations when fructose was present. Taken together, our findings show that Neu5Ac metabolism inC. glutamicumis subject to catabolite repression, which involves control by the repressor NanR.IMPORTANCENeu5Ac utilization is currently regarded as a common trait of both pathogenic and commensal bacteria. Interestingly, the nonpathogenic soil bacteriumC. glutamicumefficiently utilizes Neu5Ac as a substrate for growth. Expression of genes for Neu5Ac utilization inC. glutamicumis here shown to depend on the transcriptional regulator NanR, which is the first GntR-type regulator of Neu5Ac metabolism not to use Neu5Ac as effector but relies instead on the inducers GlcNAc-6P and ManNAc-6P. The identification of conserved NanR-binding sites in intergenic regions within the operons for Neu5Ac utilization in pathogenicCorynebacteriumspecies indicates that the mechanism for the control of Neu5Ac catabolism inC. glutamicumby NanR as described in this work is probably conserved within this genus.

Influence of RpoN on isocitrate lyase activity in Pseudomonas aeruginosa

Microbiology ◽  
2010 ◽  
Vol 156 (4) ◽  
pp. 1201-1210 ◽  
Author(s):  
Jessica M. Hagins ◽  
Jessica A. Scoffield ◽  
Sang-Jin Suh ◽  
Laura Silo-Suh
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Metabolic Pathways ◽  
Isocitrate Lyase ◽  
Tricarboxylic Acid Cycle ◽  
Acute Infection ◽  
Carbon Sources ◽  
Pulmonary Infections ◽  
Lyase Activity ◽  
Glyoxylate Pathway ◽  
Knockout Mutation

Pseudomonas aeruginosa is the major aetiological agent of chronic pulmonary infections in patients with cystic fibrosis (CF). The metabolic pathways utilized by P. aeruginosa during these infections, which can persist for decades, are poorly understood. Several lines of evidence suggest that the glyoxylate pathway, which utilizes acetate or fatty acids to replenish intermediates of the tricarboxylic acid cycle, is an important metabolic pathway for P. aeruginosa adapted to the CF lung. Isocitrate lyase (ICL) is one of two major enzymes of the glyoxylate pathway. In a previous study, we determined that P. aeruginosa is dependent upon aceA, which encodes ICL, to cause disease on alfalfa seedlings and in rat lungs. Expression of aceA in PAO1, a P. aeruginosa isolate associated with acute infection, is regulated by carbon sources that utilize the glyoxyate pathway. In contrast, expression of aceA in FRD1, a CF isolate, is constitutively upregulated. Moreover, this deregulation of aceA occurs in other P. aeruginosa isolates associated with chronic infection, suggesting that high ICL activity facilitates adaptation of P. aeruginosa to the CF lung. Complementation of FRD1 with a PAO1 clone bank identified that rpoN negatively regulates aceA. However, the deregulation of aceA in FRD1 was not due to a knockout mutation of rpoN. Regulation of the glyoxylate pathway by RpoN is likely to be indirect, and represents a unique regulatory role for this sigma factor in bacterial metabolism.

scholarly journals Genome-Wide Identification of the B-BOX Genes that Respond to Multiple Ripening Related Signals in Sweet Cherry Fruit

2021 ◽  
Vol 22 (4) ◽  
pp. 1622
Author(s):  
Yanyan Wang ◽  
Zefeng Zhai ◽  
Yueting Sun ◽  
Chen Feng ◽  
Xiang Peng ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Stress Responses ◽  
Fruit Development ◽  
Sweet Cherry ◽  
Anthocyanin Biosynthesis ◽  
Expression Patterns ◽  
Light Induction ◽  
Promoter Regions ◽  
Genome Database ◽  
Gene Structures

B-BOX proteins are zinc finger transcription factors that play important roles in plant growth, development, and abiotic stress responses. In this study, we identified 15 PavBBX genes in the genome database of sweet cherry. We systematically analyzed the gene structures, clustering characteristics, and expression patterns of these genes during fruit development and in response to light and various hormones. The PavBBX genes were divided into five subgroups. The promoter regions of the PavBBX genes contain cis-acting elements related to plant development, hormones, and stress. qRT-PCR revealed five upregulated and eight downregulated PavBBX genes during fruit development. In addition, PavBBX6, PavBBX9, and PavBBX11 were upregulated in response to light induction. We also found that ABA, BR, and GA3 contents significantly increased in response to light induction. Furthermore, the expression of several PavBBX genes was highly correlated with the expression of anthocyanin biosynthesis genes, light-responsive genes, and genes that function in multiple hormone signaling pathways. Some PavBBX genes were strongly induced by ABA, GA, and BR treatment. Notably, PavBBX6 and PavBBX9 responded to all three hormones. Taken together, BBX proteins likely play major roles in regulating anthocyanin biosynthesis in sweet cherry fruit by integrating light, ABA, GA, and BR signaling pathways.

scholarly journals The Role of Cell Metabolism in Innate Immune Memory

2020 ◽  
pp. 1-9
Author(s):  
Anaisa Valido Ferreira ◽  
Jorge Domiguéz-Andrés ◽  
Mihai Gheorghe Netea
Keyword(s):  
Metabolic Pathways ◽  
Tricarboxylic Acid Cycle ◽  
Cell Metabolism ◽  
Innate Immune ◽  
Immune Memory ◽  
Functional Changes ◽  
Trained Immunity ◽  
Health And Disease

Immunological memory is classically attributed to adaptive immune responses, but recent studies have shown that challenged innate immune cells can display long-term functional changes that increase nonspecific responsiveness to subsequent infections. This phenomenon, coined <i>trained immunity</i> or <i>innate immune memory</i>, is based on the epigenetic reprogramming and the rewiring of intracellular metabolic pathways. Here, we review the different metabolic pathways that are modulated in trained immunity. Glycolysis, oxidative phosphorylation, the tricarboxylic acid cycle, amino acid, and lipid metabolism are interplaying pathways that are crucial for the establishment of innate immune memory. Unraveling this metabolic wiring allows for a better understanding of innate immune contribution to health and disease. These insights may open avenues for the development of future therapies that aim to harness or dampen the power of the innate immune response.

scholarly journals Mitochondrial Sirtuins in Reproduction

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1047
Author(s):  
Giovanna Di Emidio ◽  
Stefano Falone ◽  
Paolo Giovanni Artini ◽  
Fernanda Amicarelli ◽  
Anna Maria D’Alessandro ◽  
...  
Keyword(s):  
Stress Responses ◽  
Metabolic Pathways ◽  
Redox Balance ◽  
Antioxidant Defenses ◽  
Metabolic Abnormalities ◽  
Female Reproduction ◽  
Mitochondrial Dysfunctions ◽  
Early Embryos ◽  
The Relationship

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.

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