scholarly journals Structural and ligand binding analyses of the periplasmic sensor domain of RsbU in Chlamydia trachomatis support a role in TCA cycle regulation

2019 ◽  
Vol 113 (1) ◽  
pp. 68-88 ◽  
Author(s):  
Katelyn R. Soules ◽  
Aidan Dmitriev ◽  
Scott D. LaBrie ◽  
Zoë E. Dimond ◽  
Benjamin H. May ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Ligand Binding ◽  
Tca Cycle ◽  
Cycle Regulation

scholarly journals The Epiphytic FernElaphoglossum luridum(Fée) Christ. (Dryopteridaceae) from Central and South America: Morphological and Physiological Responses to Water Stress

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Bruno Degaspari Minardi ◽  
Ana Paula Lorenzen Voytena ◽  
Marisa Santos ◽  
Áurea Maria Randi
Keyword(s):  
Water Stress ◽  
Water Deficit ◽  
Chlorophyll A ◽  
Tca Cycle ◽  
Photosynthetic Parameters ◽  
Relative Water ◽  
Physiological Studies ◽  
Cycle Regulation ◽  
Epiphytic Fern ◽  
Chlorophyll A Content

Elaphoglossum luridum(Fée) Christ. (Dryopteridaceae) is an epiphytic fern of the Atlantic Forest (Brazil). Anatomical and physiological studies were conducted to understand how this plant responds to water stress. TheE. luridumfrond is coriaceus and succulent, presenting trichomes, relatively thick cuticle, and sinuous cell walls in both abaxial and adaxial epidermis. Three treatments were analyzed: control, water deficit, and abscisic acid (ABA). Physiological studies were conducted through analysis of relative water content (RWC), photosynthetic pigments, chlorophyll a fluorescence, and malate content. No changes in RWC were observed among treatments; however, significant decreases in chlorophyll a content and photosynthetic parameters, including optimal irradiance (Iopt) and maximum electron transport rate (ETRmax), were determined by rapid light curves (RLC). No evidence of crassulacean acid metabolism (CAM) pathway was observed inE. luridumin response to either water deficit or exogenous application of ABA. On the other hand, malate content decreased in theE. luridumfrond after ABA treatment, seeming to downregulate malate metabolism at night, possibly through tricarboxylic acid (TCA) cycle regulation.

Pyruvate-triggered TCA cycle regulation in Staphylococcus aureus promotes tolerance to betamethasone valerate

2020 ◽  
Vol 528 (2) ◽  
pp. 318-321
Author(s):  
Yasuhiko Matsumoto ◽  
Takumi Nakashima ◽  
Otomi Cho ◽  
Tomotaka Ohkubo ◽  
Jumpei Kato ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Tca Cycle ◽  
Betamethasone Valerate ◽  
Cycle Regulation

scholarly journals A Case of Pyruvate Carboxylase Deficiency With Longer Survival and Normal Laboratory Findings

2021 ◽  
Author(s):  
Reza Bayat ◽  
Shahin Koohmanaee ◽  
Nejat Mahdieh ◽  
Fatemeh Kharaee ◽  
Maryam Shahrokhi ◽  
...  
Keyword(s):  
Pyruvate Carboxylase ◽  
Amino Acid Level ◽  
Tca Cycle ◽  
Type B ◽  
Laboratory Findings ◽  
Short Life Span ◽  
Pyruvate Carboxylase Deficiency ◽  
Almost All ◽  
Cycle Regulation ◽  
Recessive Defect

Pyruvate carboxylase deficiency (PCD) is a rare autosomal recessive defect in a biotin-containing enzyme, Pyruvate carboxylase, which is considered as an enzyme of TCA-cycle regulation, gluconeogenesis, lipogenesis, and biosynthesis of neurotransmitters. Increased lactate to pyruvate ratio and decreased three hydroxybutyrates to acetoacetate are the main biochemical features of PCD. The elevated level of Citrulline, Proline, and Lysine with a short life span has been reported previously. Patients’ survival in almost all cases is below three months. Here, the authors aimed to report a girl with manifestations of Type B of PCD and longer survival (two-year and four-month-old). This patient did not have any changes in amino acid level, which was a unique case of Type B of PCD.

scholarly journals c-Myc plays a key role in IFN-γ induced persistence of Chlamydia trachomatis

2021 ◽  
Author(s):  
Nadine Vollmuth ◽  
Sudha Janaki-Raman ◽  
Lisa Schlicker ◽  
Naziia Kurmasheva ◽  
Werner Schmitz ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Host Cell ◽  
Cell Metabolism ◽  
Tca Cycle ◽  
Tryptophan Depletion ◽  
Dependent Manner ◽  
Immune Defence ◽  
Chronic Infections ◽  
Major Mechanism ◽  
Ifn Γ

SummaryChlamydia trachomatis (Ctr) can persist over long periods of time within their host cell and thereby establish chronic infections. One of the major inducers of chlamydial persistence is interferon-gamma (IFN-γ) released by immune cells as a mechanism of immune defence. IFN-γ activates the catabolic depletion of L-tryptophan (Trp) via indoleamine 2,3-dioxygenase (IDO), resulting in persistent Chlamydia. Here we show that IFN-γ depletes c-Myc, the key regulator of host cell metabolism, in a STAT1-dependent manner. Expression of c-Myc rescued Chlamydia from IFN-γ-induced persistence in cultured cell lines, but also in human fallopian tube organoids. L-tryptophan concentrations control c-Myc levels via the PI3K-GSK3ß axis. Unbiased metabolic analysis revealed that Chlamydia infection reprograms the host cell tricarboxylic acid (TCA) cycle to support pyrimidine biosynthesis. Addition of TCA cycle intermediates or pyrimidine/purine nucleosides to infected cells rescued Chlamydia from IFN-γ-induced persistence. Thus, our results challenge the longstanding hypothesis of L-tryptophan depletion through IDO as the major mechanism of IFN-γ-induced metabolic immune defence and significantly extends the understanding of the role IFN-γ as a broad modulator of host cell metabolism.

scholarly journals Nitric Oxide Modulates Metabolic Remodeling in Inflammatory Macrophages through TCA Cycle Regulation and Itaconate Accumulation

Cell Reports ◽  
2019 ◽  
Vol 28 (1) ◽  
pp. 218-230.e7 ◽  
Author(s):  
Jade D. Bailey ◽  
Marina Diotallevi ◽  
Thomas Nicol ◽  
Eileen McNeill ◽  
Andrew Shaw ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Tca Cycle ◽  
Metabolic Remodeling ◽  
Inflammatory Macrophages ◽  
Cycle Regulation

CarR, a MarR-family regulator from Corynebacterium glutamicum, modulated antibiotic and aromatic compound resistance

2019 ◽  
Vol 476 (21) ◽  
pp. 3141-3159 ◽  
Author(s):  
Meiru Si ◽  
Can Chen ◽  
Zengfan Wei ◽  
Zhijin Gong ◽  
GuiZhi Li ◽  
...  
Keyword(s):  
Stress Response ◽  
Ligand Binding ◽  
Corynebacterium Glutamicum ◽  
Conformational Changes ◽  
Cysteine Oxidation ◽  
Transcriptional Regulatory ◽  
Ligand Free ◽  
Redox Sensing

Abstract MarR (multiple antibiotic resistance regulator) proteins are a family of transcriptional regulators that is prevalent in Corynebacterium glutamicum. Understanding the physiological and biochemical function of MarR homologs in C. glutamicum has focused on cysteine oxidation-based redox-sensing and substrate metabolism-involving regulators. In this study, we characterized the stress-related ligand-binding functions of the C. glutamicum MarR-type regulator CarR (C. glutamicum antibiotic-responding regulator). We demonstrate that CarR negatively regulates the expression of the carR (ncgl2886)–uspA (ncgl2887) operon and the adjacent, oppositely oriented gene ncgl2885, encoding the hypothetical deacylase DecE. We also show that CarR directly activates transcription of the ncgl2882–ncgl2884 operon, encoding the peptidoglycan synthesis operon (PSO) located upstream of carR in the opposite orientation. The addition of stress-associated ligands such as penicillin and streptomycin induced carR, uspA, decE, and PSO expression in vivo, as well as attenuated binding of CarR to operator DNA in vitro. Importantly, stress response-induced up-regulation of carR, uspA, and PSO gene expression correlated with cell resistance to β-lactam antibiotics and aromatic compounds. Six highly conserved residues in CarR were found to strongly influence its ligand binding and transcriptional regulatory properties. Collectively, the results indicate that the ligand binding of CarR induces its dissociation from the carR–uspA promoter to derepress carR and uspA transcription. Ligand-free CarR also activates PSO expression, which in turn contributes to C. glutamicum stress resistance. The outcomes indicate that the stress response mechanism of CarR in C. glutamicum occurs via ligand-induced conformational changes to the protein, not via cysteine oxidation-based thiol modifications.

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