scholarly journals Inactivation ofbb0184, Which Encodes Carbon Storage Regulator A, Represses the Infectivity ofBorrelia burgdorferi

2010 ◽  
Vol 79 (3) ◽  
pp. 1270-1279 ◽  
Author(s):  
Ching Wooen Sze ◽  
Chunhao Li
Keyword(s):  
Carbon Storage ◽  
Associated Factors ◽  
Animal Studies ◽  
Acetate Metabolism ◽  
Acetyl Phosphate ◽  
Wild Type ◽  
Acetyl Coa ◽  
Acetyl Coenzyme A ◽  
Carbon Storage Regulator ◽  
Subsequent Activation

ABSTRACTThe genome ofBorrelia burgdorferi, the Lyme disease spirochete, encodes a homolog (thebb0184gene product) of the carbon storage regulator A protein (CsrABb); recent studies reported that CsrABbis involved in the regulation of several infectivity factors ofB. burgdorferi. However, the mechanism involved remains unknown. In this report, acsrABbmutant was constructed and complemented in an infectious B31A3 strain. Subsequent animal studies showed that the mutant failed to establish an infection in mice, highlighting that CsrABbis required for the infectivity ofB. burgdorferi. Western blot analyses revealed that the virulence-associated factors OspC, DbpB, and DbpA were attenuated in thecsrABbmutant. The Rrp2-RpoN-RpoS pathway (σ54-σSsigma factor cascade) is a central regulon that governs the expression ofospC,dbpB, anddbpA. Further analyses found that the level of RpoS was significantly decreased in the mutant, while the level of Rrp2 remained unchanged. A recent study reported that the overexpression of BB0589, a phosphate acetyl-transferase (Pta) that converts acetyl-phosphate to acetyl-coenzyme A (CoA), led to the inhibition of RpoS and OspC expression, suggesting that acetyl-phosphate is an activator of Rrp2. Along with this report, we found that CsrABbbinds to the leader sequence of thebb0589transcript and that the intracellular level of acetyl-CoA in thecsrABbmutant was significantly increased compared to that of the wild type, suggesting that more acetyl-phosphate was being converted to acetyl-CoA in the mutant. Collectively, these results suggest that CsrABbmay influence the infectivity ofB. burgdorferivia regulation of acetate metabolism and subsequent activation of the Rrp2-RpoN-RpoS pathway.

scholarly journals Contributions of Environmental Signals and Conserved Residues to the Functions of Carbon Storage Regulator A of Borrelia burgdorferi

2013 ◽  
Vol 81 (8) ◽  
pp. 2972-2985 ◽  
Author(s):  
S. L. Rajasekhar Karna ◽  
Rajesh G. Prabhu ◽  
Ying-Han Lin ◽  
Christine L. Miller ◽  
J. Seshu
Keyword(s):  
Borrelia Burgdorferi ◽  
Carbon Storage ◽  
Vertebrate Host ◽  
Acetyl Phosphate ◽  
Mobility Shift ◽  
Acetyl Coa ◽  
Site Specific ◽  
Content Type ◽  
Environmental Signals ◽  
Carbon Storage Regulator

ABSTRACTCarbon storage regulator A ofBorrelia burgdorferi(CsrABb) contributes to vertebrate host-specific adaptation by modulating activation of the Rrp2-RpoN-RpoS pathway and is critical for infectivity. We hypothesized that the functions of CsrABbare dependent on environmental signals and on select residues. We analyzed the phenotype ofcsrABbdeletion and site-specific mutants to determine the conserved and pathogen-specific attributes of CsrABb. Levels of phosphate acetyltransferase (Pta) involved in conversion of acetyl phosphate to acetyl-coenzyme A (acetyl-CoA) and posttranscriptionally regulated by CsrABbin thecsrABbmutant were reduced from or similar to those in the control strains under unfed- or fed-tick conditions, respectively. Increased levels of supplemental acetate restored vertebrate host-responsive determinants in thecsrABbmutant to parental levels, indicating that both the levels of CsrABband the acetyl phosphate and acetyl-CoA balance contribute to the activation of the Rrp2-RpoN-RpoS pathway. Site-specific replacement of 8 key residues of CsrABb(8S) with alanines resulted in increased levels of CsrABband reduced levels of Pta and acetyl-CoA, while levels of RpoS, BosR, and other members ofrpoSregulon were elevated. Truncation of 7 amino acids at the C terminus of CsrABb(7D) resulted in reducedcsrABbtranscripts and posttranscriptionally reduced levels of FliW located upstream of CsrABb. Electrophoretic mobility shift assays revealed increased binding of 8S mutant protein to the CsrA binding box upstream ofptacompared to the parental and 7D truncated protein. Two CsrABbbinding sites were also identified upstream offliWwithin theflgKcoding sequence. These observations reveal conserved and unique functions of CsrABbthat regulate adaptive gene expression inB. burgdorferi.

scholarly journals Uropathogenic Escherichia coli CFT073 Is Adapted to Acetatogenic Growth but Does Not Require Acetate during Murine Urinary Tract Infection

2008 ◽  
Vol 76 (12) ◽  
pp. 5760-5767 ◽  
Author(s):  
Andrew T. Anfora ◽  
David K. Halladin ◽  
Brian J. Haugen ◽  
Rodney A. Welch
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Intracellular Signaling ◽  
High Energy ◽  
Acetate Metabolism ◽  
Acetyl Phosphate ◽  
Wild Type ◽  
K 12

ABSTRACT In vivo accumulation of d-serine by Escherichia coli CFT073 leads to elevated expression of PAP fimbriae and hemolysin by an unknown mechanism. Loss of d-serine catabolism by CFT073 leads to a competitive advantage during murine urinary tract infection (UTI), but loss of both d- and l-serine catabolism results in attenuation. Serine is the first amino acid to be consumed in closed tryptone broth cultures and precedes the production of acetyl phosphate, a high-energy molecule involved in intracellular signaling, and the eventual secretion of acetate. We propose that the colonization defect associated with the loss of serine catabolism is due to perturbations of acetate metabolism. CFT073 grows more rapidly on acetogenic substrates than does E. coli K-12 isolate MG1655. As shown by transcription microarray results, d-serine is catabolized into acetate via the phosphotransacetylase (pta) and acetate kinase (ackA) genes while downregulating expression of acetyl coenzyme A synthase (acs). CFT073 acs, which is unable to reclaim secreted acetate, colonized mouse bladders and kidneys in the murine model of UTI indistinguishably from the wild type. Both pta and ackA are involved in the maintenance of intracellular acetyl phosphate. CFT073 pta and ackA mutants were screened to investigate the role of acetyl phosphate in UTI pathogenesis. Both single mutants are at a competitive disadvantage relative to the wild type in the kidneys but normally colonize the bladder. CFT073 ackA pta was attenuated in both the bladder and the kidneys. Thus, we demonstrate that CFT073 is adapted to acetate metabolism as a result of requiring a proper cycling of the acetyl phosphate pathway for colonization of the upper urinary tract.

scholarly journals Genetics and Physiology of Acetate Metabolism by the Pta-Ack Pathway of Streptococcus mutans

2015 ◽  
Vol 81 (15) ◽  
pp. 5015-5025 ◽  
Author(s):  
Jeong Nam Kim ◽  
Sang-Joon Ahn ◽  
Robert A. Burne
Keyword(s):  
Streptococcus Mutans ◽  
Wild Type Strain ◽  
Acetate Metabolism ◽  
Global Changes ◽  
Acetyl Phosphate ◽  
Wild Type ◽  
Aerobic Conditions ◽  
Content Type ◽  
Atp Pool ◽  
Complex Regulation

ABSTRACTIn the dental caries pathogenStreptococcus mutans, phosphotransacetylase (Pta) catalyzes the conversion of acetyl coenzyme A (acetyl-CoA) to acetyl phosphate (AcP), which can be converted to acetate by acetate kinase (Ack), with the concomitant generation of ATP. A ΔackAmutant displayed enhanced accumulation of AcP under aerobic conditions, whereas little or no AcP was observed in the Δptaor ΔptaΔackAmutant. The Δptaand ΔptaΔackAmutants also had diminished ATP pools compared to the size of the ATP pool for the parental or ΔackAstrain. Surprisingly, when exposed to oxidative stress, the ΔptaΔackAstrain appeared to regain the capacity to produce AcP, with a concurrent increase in the size of the ATP pool compared to that for the parental strain. The ΔackAand ΔptaΔackAmutants exhibited enhanced (p)ppGpp accumulation, whereas the strain lacking Pta produced less (p)ppGpp than the wild-type strain. The ΔackAand ΔptaΔackAmutants displayed global changes in gene expression, as assessed by microarrays. All strains lacking Pta, which had defects in AcP production under aerobic conditions, were impaired in their abilities to form biofilms when glucose was the growth carbohydrate. Collectively, these data demonstrate the complex regulation of the Pta-Ack pathway and critical roles for these enzymes in processes that appear to be essential for the persistence and pathogenesis ofS. mutans.

scholarly journals The Intracellular Concentration of Acetyl Phosphate in Escherichia coli Is Sufficient for Direct Phosphorylation of Two-Component Response Regulators

2007 ◽  
Vol 189 (15) ◽  
pp. 5574-5581 ◽  
Author(s):  
Adam H. Klein ◽  
Ana Shulla ◽  
Sylvia A. Reimann ◽  
David H. Keating ◽  
Alan J. Wolfe
Keyword(s):  
Escherichia Coli ◽  
Intracellular Concentration ◽  
Phosphoryl Transfer ◽  
Acetyl Phosphate ◽  
Wild Type ◽  
Response Regulators ◽  
Acetyl Coenzyme A ◽  
Global Signal ◽  
Two Component ◽  
Layer Chromatography

ABSTRACT Acetyl phosphate, the intermediate of the AckA-Pta pathway, acts as a global signal in Escherichia coli. Although acetyl phosphate clearly signals through two-component response regulators, it remains unclear whether acetyl phosphate acts as a direct phospho donor or functions through an indirect mechanism. We used two-dimensional thin-layer chromatography to measure the relative concentrations of acetyl phosphate, acetyl coenzyme A, ATP, and GTP over the course of the entire growth curve. We estimated that the intracellular concentration of acetyl phosphate in wild-type cells reaches at least 3 mM, a concentration sufficient to activate two-component response regulators via direct phosphoryl transfer.

scholarly journals Regulation of Acetyl Coenzyme A Synthetase inEscherichia coli

2000 ◽  
Vol 182 (15) ◽  
pp. 4173-4179 ◽  
Author(s):  
Suman Kumari ◽  
Christine M. Beatty ◽  
Douglas F. Browning ◽  
Stephen J. W. Busby ◽  
Erica J. Simel ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Coenzyme A ◽  
Tricarboxylic Acid Cycle ◽  
Receptor Protein ◽  
Acetate Metabolism ◽  
Glyoxylate Shunt ◽  
Acetyl Coa ◽  
Metabolic Switch ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme

ABSTRACT Cells of Escherichia coli growing on sugars that result in catabolite repression or amino acids that feed into glycolysis undergo a metabolic switch associated with the production and utilization of acetate. As they divide exponentially, these cells excrete acetate via the phosphotransacetylase-acetate kinase pathway. As they begin the transition to stationary phase, they instead resorb acetate, activate it to acetyl coenzyme A (acetyl-CoA) by means of the enzyme acetyl-CoA synthetase (Acs) and utilize it to generate energy and biosynthetic components via the tricarboxylic acid cycle and the glyoxylate shunt, respectively. Here, we present evidence that this switch occurs primarily through the induction of acs and that the timing and magnitude of this induction depend, in part, on the direct action of the carbon regulator cyclic AMP receptor protein (CRP) and the oxygen regulator FNR. It also depends, probably indirectly, upon the glyoxylate shunt repressor IclR, its activator FadR, and many enzymes involved in acetate metabolism. On the basis of these results, we propose that cells induce acs, and thus their ability to assimilate acetate, in response to rising cyclic AMP levels, falling oxygen partial pressure, and the flux of carbon through acetate-associated pathways.

scholarly journals Genome Sequence of Serratia marcescens MSU97, a Plant-Associated Bacterium That Makes Multiple Antibiotics

2017 ◽  
Vol 5 (9) ◽  
Author(s):  
Miguel A. Matilla ◽  
Zulema Udaondo ◽  
Tino Krell ◽  
George P. C. Salmond
Keyword(s):  
Serratia Marcescens ◽  
Genome Sequence ◽  
Coenzyme A ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Acetyl Coenzyme A ◽  
Content Type ◽  
Acetyl Coenzyme ◽  
Multiple Antibiotics

ABSTRACT Serratia marcescens MSU97 was isolated from the Guayana region of Venezuela due to its ability to suppress plant-pathogenic oomycetes. Here, we report the genome sequence of MSU97, which produces various antibiotics, including the bacterial acetyl-coenzyme A (acetyl-CoA) carboxylase inhibitor andrimid, the chlorinated macrolide oocydin A, and the red linear tripyrrole antibiotic prodigiosin.

Acetate metabolism in Escherichia coli

1978 ◽  
Vol 24 (2) ◽  
pp. 149-153 ◽  
Author(s):  
T. M. Lakshmi ◽  
Robert B. Helling
Keyword(s):  
Isocitrate Dehydrogenase ◽  
Citrate Synthase ◽  
Isocitrate Lyase ◽  
Glyoxylate Cycle ◽  
Acetate Metabolism ◽  
Wild Type ◽  
Intermediary Metabolites ◽  
Lyase Activity ◽  
Acetate Medium ◽  
The Glyoxylate Cycle

Levels of several intermediary metabolites were measured in cells grown in acetate medium in order to test the hypothesis that the glyoxylate cycle is repressed by phosphoenolpyruvate (PEP). Wild-type cells had less PEP than either isocitrate dehydrogenase – deficient cells (which had greater isocitrate lyase activity than the wild type) or isocitrate dehydrogenase – deficient, citrate synthase – deficient cells (which are poorly inducible). Thus induction of the glyoxylate cycle is more complicated than a simple function of PEP concentration. No correlation between enzyme activity and the level of oxaloacetate, pyruvate, or citrate was found either. Citrate was synthesized in citrate synthase – deficient mutants, possibly via citrate lyase.

scholarly journals Impact of a Novel W2027L Mutation and Non-Target Site Resistance on Acetyl-CoA Carboxylase-Inhibiting Herbicides in a French Lolium multiflorum Population

Genes ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1838
Author(s):  
Shiv Shankhar Kaundun ◽  
Joe Downes ◽  
Lucy Victoria Jackson ◽  
Sarah-Jane Hutchings ◽  
Eddie Mcindoe
Keyword(s):  
Lolium Multiflorum ◽  
Restriction Enzymes ◽  
Target Site ◽  
Cereal Crops ◽  
Acetyl Coa Carboxylase ◽  
Wild Type ◽  
Resistance Mutations ◽  
Acetyl Coa ◽  
Pcr Product ◽  
Target Site Resistance

Herbicides that inhibit acetyl-CoA carboxylase (ACCase) are among the few remaining options for the post-emergence control of Lolium species in small grain cereal crops. Here, we determined the mechanism of resistance to ACCase herbicides in a Lolium multiflorum population (HGR) from France. A combined biological and molecular approach detected a novel W2027L ACCase mutation that affects aryloxyphenoxypropionate (FOP) but not cyclohexanedione (DIM) or phenylpyraxoline (DEN) subclasses of ACCase herbicides. Both the wild-type tryptophan and mutant leucine 2027-ACCase alleles could be positively detected in a single DNA-based-derived polymorphic amplified cleaved sequence (dPACS) assay that contained the targeted PCR product and a cocktail of two discriminating restriction enzymes. Additionally, we identified three well-characterised I1781L, I2041T, and D2078G ACCase target site resistance mutations as well as non-target site resistance in HGR. The non-target site component endowed high levels of resistance to FOP herbicides whilst partially impacting on the efficacy of pinoxaden and cycloxydim. This study adequately assessed the contribution of the W2027L mutation and non-target site mechanism in conferring resistance to ACCase herbicides in HGR. It also highlights the versatility and robustness of the dPACS method to simultaneously identify different resistance-causing alleles at a single ACCase codon.

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