Molecular analysis of ampR and ampD to understand variability in inducible expression of "BlaB-like" cephalosporinase in Yersinia enterocolitica biotype 1A.

08:00 EDT 10th April 2019 | BioPortfolio

Summary of "Molecular analysis of ampR and ampD to understand variability in inducible expression of "BlaB-like" cephalosporinase in Yersinia enterocolitica biotype 1A."

Yersinia enterocolitica strains produce two chromosomal β‑lactamases, BlaA - a constitutively produced penicillinase, and BlaB - an inducible "AmpC-type" cephalosporinase. As in other members of Enterobacteriaceae, expression of ampC in Y. enterocolitica is regulated by the genes - ampR and ampD. The ampR encodes a transcriptional regulator which represses the expression of ampC and, ampD encodes a cytoplasmic N‑acetyl‑anhydromuramyl‑l‑alanine amidase which participates in recycling of peptidoglycan. Exposure of bacteria to antibiotics like imipenem and cefoxitin results in generation and accumulation of large quantities of muropeptides in cytoplasm which is beyond the recycling capability of AmpD. These muropeptides bind to AmpR, converting it into an activator of ampC expression (ampC de-repression). Earlier studies from our laboratory indicated that instead of BlaB, Y. enterocolitica biotype 1A strains produced a "BlaB-like" enzyme which was non-heterogeneous and showed a differential expression when induced with imipenem. The detection of "BlaB-like" cephalosporinase which was also induced differentially in Y. enterocolitica biotype 1A strains presented an opportunity to discern newer mechanisms, if any, which may underlie inducible expression of "AmpC-type" cephalosporinases. Thus, the objective of the present study was to understand the role of ampR and ampD in regulating differential expression of "BlaB-like" cephalosporinases in biotype 1A strains. Analysis of promoters and amino acid sequences of AmpR revealed that these were conserved in all strains of biotype 1A. Analysis of AmpD amino acid sequences revealed that five variants of AmpD were present which did not contribute to hyper-inducible production of "BlaB-like" enzyme. In-silico prediction of the mRNA secondary structures of ampD revealed significant differences, which might have affected the rate of translation of ampD and accumulation of un-recycled muropeptides inside the cell leading to hyper production of "BlaB-like" cephalosporinases in some Y. enterocolitica biotype 1A strains. The findings provide newer insights to our understanding of the mechanisms underlying regulation of expression of "AmpC-type" β‑lactamases.


Journal Details

This article was published in the following journal.

Name: Gene
ISSN: 1879-0038


DeepDyve research library

PubMed Articles [36676 Associated PubMed Articles listed on BioPortfolio]

ampD homologs in biotypes of Yersinia enterocolitica: Implications in regulation of chromosomal AmpC-type cephalosporinases.

Inducible 'AmpC-type' chromosomal cephalosporinases have been reported to be differentially expressed in different biotypes of Yersinia entercolocolitica. AmpD amidases are key regulators of the expre...

Gene expression variability - the other dimension in transcriptome analysis.

Transcriptome sequencing is a powerful technique to study molecular changes that underlie the differences in physiological conditions and disease progression. A typical question that is posed in such ...

DiCre-Based Inducible Gene Expression.

Induction of gene expression is a valuable approach for functional studies since it allows for the assessment of phenotypes without the need for clonal selection. Inducible expression can find a wide ...

Cellular network modeling and single cell gene expression analysis reveals novel hepatic stellate cell phenotypes controlling liver regeneration dynamics.

Recent results from single cell gene and protein regulation studies are starting to uncover the previously underappreciated fact that individual cells within a population exhibit high variability in t...

(Differential) Co-Expression Analysis of Gene Expression: A Survey of Best Practices.

Analysis of gene expression data is widely used in transcriptomic studies to understand functions of molecules inside a cell and interactions among molecules. Differential co-expression analysis studi...

Clinical Trials [7401 Associated Clinical Trials listed on BioPortfolio]

Molecular Predictors of Cancer in Patients at High Risk of Lung Cancer

RATIONALE: Using samples of blood, urine, sputum, and tissue from patients at high risk of cancer for laboratory studies may help doctors learn more about changes that may occur in DNA and...

The Gene Expression Studies of the Role of Tumor Microenvironments in Tumor Progression

The purpose of this study is to analyze the gene expression patterns associated with various microenvironmental stresses in tumors to understand their roles in tumor progression and treatm...

Investigation of the HDAC4 Copy Number Variation and Its Effect on Gene and Protein Expression in Patients With ASD

Specific Aims of this study: 1. To understand the distribution of HDAC4 CNV in the families of the ASD patients with HDAC4 CNV; 2. To perform the analysis of gene expressi...

Molecular Analysis Of Solid Tumors

This study will prospectively characterize the molecular, cellular and genetic properties of primary and metastatic neuroblastoma, osteosarcoma, retinoblastoma, Ewing sarcoma family of tum...

Gene Expression Profiling and Phototoxicity in Adults and Children Exposed to Ultraviolet Radiation

RATIONALE: Certain drugs, such as doxycycline and voriconazole, may cause phototoxicity when a patient is exposed to ultraviolet (UV) radiation (sunlight). Studying the pattern of gene exp...

Medical and Biotech [MESH] Definitions

MOLECULAR BIOLOGY techniques used in the diagnosis of disease. Included are such techniques as IN SITU HYBRIDIZATION of chromosomes for CYTOGENETIC ANALYSIS; OLIGONUCLEOTIDE ARRAY SEQUENCE ANALYSIS of gene expression patterns in disease states; identification of pathogenic organisms by analysis of species specific DNA sequences; and detection of mutations with POLYMERASE CHAIN REACTION.

The molecular designing of drugs for specific purposes (such as DNA-binding, enzyme inhibition, anti-cancer efficacy, etc.) based on knowledge of molecular properties such as activity of functional groups, molecular geometry, and electronic structure, and also on information cataloged on analogous molecules. Drug design is generally computer-assisted molecular modeling and does not include pharmacokinetics, dosage analysis, or drug administration analysis.

Using MOLECULAR BIOLOGY techniques, such as DNA SEQUENCE ANALYSIS; PULSED-FIELD GEL ELECTROPHORESIS; and DNA FINGERPRINTING, to identify, classify, and compare organisms and their subtypes.

A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis.

Heat and cold stress-inducible, transcription factors that bind to inverted 5'-NGAAN-3' pentamer DNA sequences and are regulated by poly(ADP) ribosylation. They play essential roles as transcriptional activators of the HEAT-SHOCK RESPONSE by inducing expression of large classes of MOLECULAR CHAPERONES and heat-shock proteins. They also function in DNA REPAIR; transcriptional reactivation of latent HIV-1; and pre-mRNA processing and nuclear export of HSP70 HEAT-SHOCK PROTEINS during heat stress.

Quick Search


DeepDyve research library

Relevant Topic

Enzymes are proteins that catalyze (i.e., increase the rates of) chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical re...

Searches Linking to this Article