scholarly journals Impact of the Histidine-Containing Phosphocarrier Protein HPr on Carbon Metabolism and Virulence in Staphylococcus aureus

2021 ◽  
Vol 9 (3) ◽  
pp. 466
Author(s):  
Linda Pätzold ◽  
Anne-Christine Brausch ◽  
Evelyn-Laura Bielefeld ◽  
Lisa Zimmer ◽  
Greg A. Somerville ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Protein A ◽  
Common Mechanism ◽  
Central Metabolism ◽  
Phosphotransferase System ◽  
Reading Frame ◽  
Bacterial Physiology ◽  
Catabolite Control Protein A ◽  
Regulatory Functions

Carbon catabolite repression (CCR) is a common mechanism pathogenic bacteria use to link central metabolism with virulence factor synthesis. In gram-positive bacteria, catabolite control protein A (CcpA) and the histidine-containing phosphocarrier protein HPr (encoded by ptsH) are the predominant mediators of CCR. In addition to modulating CcpA activity, HPr is essential for glucose import via the phosphotransferase system. While the regulatory functions of CcpA in Staphylococcus aureus are largely known, little is known about the function of HPr in CCR and infectivity. To address this knowledge gap, ptsH mutants were created in S. aureus that either lack the open reading frame or harbor a ptsH variant carrying a thymidine to guanosine mutation at position 136, and the effects of these mutations on growth and metabolism were assessed. Inactivation of ptsH altered bacterial physiology and decreased the ability of S. aureus to form a biofilm and cause infections in mice. These data demonstrate that HPr affects central metabolism and virulence in S. aureus independent of its influence on CcpA regulation.

scholarly journals Malonyl-proteome profiles of Staphylococcus aureus reveal lysine malonylation modification in enzymes involved in energy metabolism

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yanan Shi ◽  
Jingjing Zhu ◽  
Yan Xu ◽  
Xiaozhao Tang ◽  
Zushun Yang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Energy Metabolism ◽  
Active Sites ◽  
Current Knowledge ◽  
Tricarboxylic Acid Cycle ◽  
Protein A ◽  
Pentose Phosphate ◽  
Post Translational Modification ◽  
Bacterial Physiology ◽  
Dihydrolipoyl Dehydrogenase

Abstract Background Protein lysine malonylation, a novel post-translational modification (PTM), has been recently linked with energy metabolism in bacteria. Staphylococcus aureus is the third most important foodborne pathogen worldwide. Nonetheless, substrates and biological roles of malonylation are still poorly understood in this pathogen. Results Using anti-malonyl-lysine antibody enrichment and high-resolution LC-MS/MS analysis, 440 lysine-malonylated sites were identified in 281 proteins of S. aureus strain. The frequency of valine in position − 1 and alanine at + 2 and + 4 positions was high. KEGG pathway analysis showed that six categories were highly enriched, including ribosome, glycolysis/gluconeogenesis, pentose phosphate pathway (PPP), tricarboxylic acid cycle (TCA), valine, leucine, isoleucine degradation, and aminoacyl-tRNA biosynthesis. In total, 31 malonylated sites in S. aureus shared homology with lysine-malonylated sites previously identified in E. coli, indicating malonylated proteins are highly conserved among bacteria. Key rate-limiting enzymes in central carbon metabolic pathways were also found to be malonylated in S. aureus, namely pyruvate kinase (PYK), 6-phosphofructokinase, phosphoglycerate kinase, dihydrolipoyl dehydrogenase, and F1F0-ATP synthase. Notably, malonylation sites were found at or near protein active sites, including KH domain protein, thioredoxin, alanine dehydrogenase (ALD), dihydrolipoyl dehydrogenase (LpdA), pyruvate oxidase CidC, and catabolite control protein A (CcpA), thus suggesting that lysine malonylation may affect the activity of such enzymes. Conclusions Data presented herein expand the current knowledge on lysine malonylation in prokaryotes and indicate the potential roles of protein malonylation in bacterial physiology and metabolism.

scholarly journals Novel Chromosomally Encoded Multidrug Efflux Transporter MdeA in Staphylococcus aureus

2004 ◽  
Vol 48 (3) ◽  
pp. 909-917 ◽  
Author(s):  
Jianzhong Huang ◽  
Paul W. O'Toole ◽  
Wei Shen ◽  
Heather Amrine-Madsen ◽  
Xinhe Jiang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Major Facilitator Superfamily ◽  
Multidrug Efflux ◽  
Expression Library ◽  
Reading Frame ◽  
Transmembrane Segments ◽  
Antibiotic Compounds ◽  
Major Facilitator ◽  
Spontaneous Mutants

ABSTRACT Antibiotic efflux is an important mechanism of resistance in pathogenic bacteria. Here we describe the identification and characterization of a novel chromosomally encoded multidrug resistance efflux protein in Staphylococcus aureus, MdeA (multidrug efflux A). MdeA was identified from screening an S. aureus open reading frame expression library for resistance to antibiotic compounds. When overexpressed, MdeA confers resistance on S. aureus to a range of quaternary ammonium compounds and antibiotics, but not fluoroquinolones. MdeA is a 52-kDa protein with 14 predicted transmembrane segments. It belongs to the major facilitator superfamily and is most closely related, among known efflux proteins, to LmrB of Bacillus subtilis and EmrB of Escherichia coli. Overexpression of mdeA in S. aureus reduced ethidium bromide uptake and enhanced its efflux, which could be inhibited by reserpine and abolished by an uncoupler. The mdeA promoter was identified by primer extension. Spontaneous mutants selected for increased resistance to an MdeA substrate had undergone mutations in the promoter for mdeA, and their mdeA transcription levels were increased by as much as 15-fold. The mdeA gene was present in the genomes of all six strains of S. aureus examined. Uncharacterized homologs of MdeA were present elsewhere in the S. aureus genome, but their overexpression did not mediate resistance to the antibacterials tested. However, MdeA homologs were identified in other bacteria, including Bacillus anthracis, some of which were shown to be functional orthologs of MdeA.

scholarly journals Genome-wide analysis of in vivo CcpA binding with and without its key co-factor HPr in the major human pathogen group A Streptococcus

2020 ◽  
Author(s):  
Sruti DebRoy ◽  
Victor Aliaga Tobar ◽  
Gabriel Galvez ◽  
Srishtee Arora ◽  
Xiaowen Liang ◽  
...  
Keyword(s):  
Dna Binding ◽  
Pathogenic Bacteria ◽  
Group A Streptococcus ◽  
Protein A ◽  
Data Availability ◽  
Human Pathogen ◽  
Transcript Levels ◽  
Catabolite Control Protein A ◽  
Group A

SummaryCatabolite control protein A (CcpA) is a master regulator of carbon source utilization and contributes to the virulence of numerous medically important Gram-positive bacteria. Most functional assessments of CcpA, including interaction with its key co-factor HPr, have been performed in non-pathogenic bacteria. In this study we aimed to identify the in vivo DNA binding profile of CcpA and assess the extent to which HPr is required for CcpA-mediated regulation and DNA binding in the major human pathogen group A Streptococcus (GAS). Using a combination RNAseq/ChIPseq approach, we found that CcpA affects transcript levels of 514 of 1667 GAS genes (31%) whereas direct DNA binding was identified for 105 GAS genes. Three of the directly regulated genes encode the key GAS virulence factors Streptolysin S, PrtS (IL-8 degrading proteinase), and SpeB (cysteine protease). Mutating CcpA Val301 to Ala (strain 2221-CcpA-V301A) abolished interaction between CcpA and HPr and impacted the transcript levels of 205 genes (40%) in the total CcpA regulon. By ChIPseq analysis, CcpAV301A bound to DNA from 74% of genes bound by wild-type CcpA, but generally with lower affinity. These data delineate the direct CcpA regulon and clarify the HPr-dependent and independent activities of CcpA in a key pathogenic bacterium.Data sharing and data availabilityThe data that support the findings of this study are available from the corresponding author upon reasonable request.

scholarly journals Mechanism of Gene Regulation by a Staphylococcus aureus Toxin

mBio ◽  
2016 ◽  
Vol 7 (5) ◽  
Author(s):  
Hwang-Soo Joo ◽  
Som S. Chatterjee ◽  
Amer E. Villaruz ◽  
Seth W. Dickey ◽  
Vee Y. Tan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Staphylococcus Aureus ◽  
Gene Regulation ◽  
Toxin Production ◽  
Bacterial Toxin ◽  
Human Pathogen ◽  
Bacterial Physiology ◽  
Functional Specification ◽  
Gene Regulatory ◽  
Regulatory Functions

ABSTRACT The virulence of many bacterial pathogens, including the important human pathogen Staphylococcus aureus , depends on the secretion of frequently large amounts of toxins. Toxin production involves the need for the bacteria to make physiological adjustments for energy conservation. While toxins are primarily targets of gene regulation, such changes may be accomplished by regulatory functions of the toxins themselves. However, mechanisms by which toxins regulate gene expression have remained poorly understood. We show here that the staphylococcal phenol-soluble modulin (PSM) toxins have gene regulatory functions that, in particular, include inducing expression of their own transport system by direct interference with a GntR-type repressor protein. This capacity was most pronounced in PSMs with low cytolytic capacity, demonstrating functional specification among closely related members of that toxin family during evolution. Our study presents a molecular mechanism of gene regulation by a bacterial toxin that adapts bacterial physiology to enhanced toxin production. IMPORTANCE Toxins play a major role in many bacterial diseases. When toxins are produced during infection, the bacteria need to balance this energy-consuming task with other physiological processes. However, it has remained poorly understood how toxins can impact gene expression to trigger such adaptations. We found that specific members of a toxin family in the major human pathogen Staphylococcus aureus have evolved for gene regulatory purposes. These specific toxins interact with a DNA-binding regulator protein to enable production of the toxin export machinery and ascertain that the machinery is not expressed when toxins are not made and it is not needed. Our study gives mechanistic insight into how toxins may directly adjust bacterial physiology to times of toxin production during infection.

scholarly journals CcpA-Dependent and -Independent Control of Beta-Galactosidase Expression in Streptococcus pneumoniae Occurs via Regulation of an Upstream Phosphotransferase System-Encoding Operon

2007 ◽  
Vol 189 (14) ◽  
pp. 5183-5192 ◽  
Author(s):  
Greer E. Kaufman ◽  
Janet Yother
Keyword(s):  
Streptococcus Pneumoniae ◽  
Protein A ◽  
Surface Protein ◽  
Growth Conditions ◽  
Spontaneous Mutant ◽  
Galactosidase Activity ◽  
Phosphotransferase System ◽  
Catabolite Control Protein A ◽  
Responsive Element ◽  
A Site

ABSTRACT A spontaneous mutant of Streptococcus pneumoniae strain D39 exhibiting elevated β-galactosidase activity was identified. We determined that the β-galactosidase activity was due to BgaA, a surface protein in S. pneumoniae, and that the expression of bgaA was regulated. Transcription analyses demonstrated expression of bgaA in the constitutive β-galactosidase (BgaAC) mutant, but not in the parent. β-Galactosidase expression was induced in the parent under specific growth conditions; however, the levels did not reach those of the BgaAC mutant. We localized the mutation resulting in the BgaAC phenotype to a region upstream of bgaA and in the promoter of a phosphoenolpyruvate-dependent phosphotransferase system (PTS) operon. The mutation was in a catabolite-responsive element (cre) and affected the binding of CcpA (catabolite control protein A), a key regulator of many carbon metabolism genes. The pts operon and bgaA were cotranscribed, and their transcription was regulated by CcpA. Deletion of ccpA altered β-galactosidase activity, leading to a sevenfold increase in the parent but a fivefold decrease in the BgaAC mutant. The resulting β-galactosidase activities were the same in the two strains, suggesting the presence of a second repressor. The presence of glucose in the growth medium resulted in pts-bgaA repression by both CcpA and the second repressor, with the latter being important in responding to the glucose concentration. Expression of β-galactosidase is important for S. pneumoniae adherence during colonization of the nasopharynx, a site normally devoid of glucose. CcpA and environmental glucose concentrations thus appear to play important roles in the regulation of a niche-specific virulence factor.

scholarly journals Repair of Global Regulators in Staphylococcus aureus 8325 and Comparative Analysis with Other Clinical Isolates

2010 ◽  
Vol 78 (6) ◽  
pp. 2877-2889 ◽  
Author(s):  
Silvia Herbert ◽  
Anne-Kathrin Ziebandt ◽  
Knut Ohlsen ◽  
Tina Schäfer ◽  
Michael Hecker ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Hemolytic Activity ◽  
Protein Pattern ◽  
Protein A ◽  
Wild Type ◽  
Global Regulators ◽  
Regulatory Functions ◽  
Highly Virulent ◽  
Model Strain ◽  
Regulatory Phenotype

ABSTRACT The pathogenicity of Staphylococcus aureus strains varies tremendously (as seen with animals). It is largely dependent on global regulators, which control the production of toxins, virulence, and fitness factors. Despite the vast knowledge of staphylococcal molecular genetics, there is still widespread dispute over what factors must come together to make a strain highly virulent. S. aureus NCTC8325 (RN1 and derivatives) is a widely used model strain for which an incomparable wealth of knowledge has accumulated in the almost 50 years since its isolation. Although RN1 has functional agr, sarA, and sae global regulators, it is defective in two regulatory genes, rsbU (a positive activator of SigB) and tcaR (an activator of protein A transcription), and is therefore considered by many to be a poor model for studies of regulation and virulence. Here, we repaired these genes and compared the resulting RN1 derivatives with other widely used strains, Newman, USA300, UAMS-1, and COL, plus the parental RN1, with respect to growth, extracellular protein pattern, hemolytic activity, protein A production, pigmentation, biofilm formation, and mouse lethality. The tcaR-repaired strain, showed little alteration in these properties. However, the rsbU-repaired strain was profoundly altered. Hemolytic activity was largely decreased, the exoprotein pattern became much more similar to that of typical wild-type (wt) S. aureus, and there was a surprising increase in mouse lethality. We note that each of the strains tested has a mutational alteration in one or more other regulatory functions, and we conclude that the repaired RN1 is a good model strain for studies of staphylococcal regulation and pathobiology; although strain Newman has been used extensively for such studies in recent years, it has a missense mutation in saeS, the histidine kinase component of the sae signaling module, which profoundly alters its regulatory phenotype. If this mutation were repaired, Newman would be considerably improved as a model strain.

scholarly journals Cigarette Smoke Increases Staphylococcus aureus Biofilm Formation via Oxidative Stress

2012 ◽  
Vol 80 (11) ◽  
pp. 3804-3811 ◽  
Author(s):  
Ritwij Kulkarni ◽  
Swati Antala ◽  
Alice Wang ◽  
Fábio E. Amaral ◽  
Ryan Rampersaud ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cigarette Smoke ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Protein A ◽  
Model Organism ◽  
Human Cells ◽  
Dependent Manner ◽  
Content Type ◽  
Tract Infections

ABSTRACTThe strong epidemiological association between cigarette smoke (CS) exposure and respiratory tract infections is conventionally attributed to immunosuppressive and irritant effects of CS on human cells. Since pathogenic bacteria such asStaphylococcus aureusare members of the normal microbiota and reside in close proximity to human nasopharyngeal cells, we hypothesized that bioactive components of CS might affect these organisms and potentiate their virulence. UsingStaphylococcus aureusas a model organism, we observed that the presence of CS increased both biofilm formation and host cell adherence. Analysis of putative molecular pathways revealed that CS exposure decreased expression of the quorum-sensingagrsystem, which is involved in biofilm dispersal, and increased transcription of biofilm inducers such assarAandrbf. CS contains bioactive compounds, including free radicals and reactive oxygen species, and we observed transcriptional induction of bacterial oxidoreductases, including superoxide dismutase, following exposure. Moreover, pretreatment of CS with an antioxidant abrogated CS-mediated enhancement of biofilms. Exposure of bacteria to hydrogen peroxide alone increased biofilm formation. These observations are consistent with the hypothesis that CS induces staphylococcal biofilm formation in an oxidant-dependent manner. CS treatment induced transcription offnbA(encoding fibronectin binding protein A), leading to increased binding of CS-treated staphylococci to immobilized fibronectin and increased adherence to human cells. These observations indicate that the bioactive effects of CS may extend to the resident microbiota of the nasopharynx, with implications for the pathogenesis of respiratory infection in CS-exposed humans.

Identification of a Novel Inhibitor of Catabolite Control Protein A from Staphylococcus aureus

2020 ◽  
Vol 6 (3) ◽  
pp. 347-354 ◽  
Author(s):  
Qi Huang ◽  
Zhemin Zhang ◽  
Huinan Li ◽  
Yu Guo ◽  
Xiangwen Liao ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Protein A ◽  
Catabolite Control Protein A ◽  
Control Protein ◽  
Catabolite Control
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