EcoliHub logo

Try the new EcoliHub and let us know what you'd like to see.

PMID:15489430

From EcoliWiki

Jump to: navigation, search

Contents

Van Dyk, TK, Templeton, LJ, Cantera, KA, Sharpe, PL and Sariaslani, FS (2004) Characterization of the Escherichia coli AaeAB efflux pump: a metabolic relief valve?J. Bacteriol. 186:7196-204

Abstract Treatment of Escherichia coli with p-hydroxybenzoic acid (pHBA) resulted in upregulation of yhcP, encoding a protein of the putative efflux protein family. Also upregulated were the adjacent genes yhcQ, encoding a protein of the membrane fusion protein family, and yhcR, encoding a small protein without a known or suggested function. The function of the upstream, divergently transcribed gene yhcS, encoding a regulatory protein of the LysR family, in regulating expression of yhcRQP was shown. Furthermore, it was demonstrated that several aromatic carboxylic acid compounds serve as inducers of yhcRQP expression. The efflux function encoded by yhcP was proven by the hypersensitivity to pHBA of a yhcP mutant strain. A yhcS mutant strain was also hypersensitive to pHBA. Expression of yhcQ and yhcP was necessary and sufficient for suppression of the pHBA hypersensitivity of the yhcS mutant. Only a few aromatic carboxylic acids of hundreds of diverse compounds tested were defined as substrates of the YhcQP efflux pump. Thus, we propose renaming yhcS, yhcR, yhcQ, and yhcP, to reflect their role in aromatic carboxylic acid efflux, to aaeR, aaeX, aaeA, and aaeB, respectively. The role of pHBA in normal E. coli metabolism and the highly regulated expression of the AaeAB efflux system suggests that the physiological role may be as a "metabolic relief valve" to alleviate toxic effects of imbalanced metabolism.
Links PubMed

Significance

You can help EcoliWiki by summarizing why this paper is useful

Useful Materials and Methods

You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.

Annotations

Gene productQualifierGO IDGO term nameEvidence Codewith/fromAspectNotesStatus

aaeA:Gene_Product(s)

GO:0042221

response to chemical stimulus

IDA: Inferred from Direct Assay

P

The authors used DNA microarray analysis to show that expression of the aaeA gene was induced in the presence of p-hydroxybenzoic acid (pHBA) (pp 7198).

complete

aaeB:Gene_Product(s)

GO:0006810

transport

IMP: Inferred from Mutant Phenotype

P

E. coli aaeB- mutants were greater than 8 times more sensitive to p-hydroxybenzoic acid (pHBA) and other aromatic carboxylic acids (Table 3).

complete

aaeA:Gene_Product(s)

GO:0046942

carboxylic acid transport

IGI: Inferred from Genetic Interaction

EcoliWiki:aaeB

P

Zone of growth inhibition assays showed that expression of AaeA is required for restoration of wild-type resistance to p-hydroxybenzoic acid (pHBA) (pp. 7200).

complete

aaeB:Gene_Product(s)

GO:0046942

carboxylic acid transport

IGI: Inferred from Genetic Interaction

EcoliWiki:aaeA

P

E. coli aaeB- mutants were greater than 8 times more sensitive to p-hydroxybenzoic acid (pHBA) and other aromatic carboxylic acids (Table 3).

complete

aaeB:Gene_Product(s)

GO:0042221

response to chemical stimulus

IGI: Inferred from Genetic Interaction

EcoliWiki:aaeA

P

complete

aaeA:Gene_Product(s)

GO:0006810

transport

IGI: Inferred from Genetic Interaction

EcoliWiki:aaeB

P

AaeA was shown to be a required component of an efflux pump specific to aromatic carboxylic acids (Table 3).

complete

aaeR:Gene_Product(s)

GO:0006350

transcription

IMP: Inferred from Mutant Phenotype

P

In bioluminescence response assays, aaeR- mutants were unable to induce expression of aaeABX in the presence of increasing concentrations of p-hydroxybenzoic acid (pHBA) unless aaeR was provided in trans from a plasmid (Table 2).

complete

aaeR:Gene_Product(s)

GO:0006355

regulation of transcription, DNA-dependent

IMP: Inferred from Mutant Phenotype

P

complete

aaeR:Gene_Product(s)

GO:0016563

transcription activator activity

IMP: Inferred from Mutant Phenotype

F

complete

EcoliWiki Links

Add links to pages that link here (e.g. gene, product, method pages)

References

See Help:References for how to manage references in EcoliWiki.

Personal tools
page contributors