Indole-3-acetic acid regulates the central metabolic pathways in Escherichia coli.
The physiological changes induced by indoleacetic acid (IAA) treatment were investigated in the totally sequenced Escherichia coli K-12 MG1655. DNA macroarrays were used to measure the mRNA levels for all the 4290 E. coli protein-coding genes; 50 genes (1.1 %) exhibited significantly different expression profiles. In particular, genes involved in the tricarboxylic acid cycle, the glyoxylate shunt and amino acid biosynthesis (leucine, isoleucine, valine and proline) were up-regulated, whereas the fermentative adhE gene was down-regulated. To confirm the indications obtained from the macroarray analysis the activity of 34 enzymes involved in central metabolism was measured; this showed an activation of the tricarboxylic acid cycle and the glyoxylate shunt. The malic enzyme, involved in the production of pyruvate, and pyruvate dehydrogenase, required for the channelling of pyruvate into acetyl-CoA, were also induced in IAA-treated cells. Moreover, it was shown that the enhanced production of acetyl-CoA and the decrease of NADH/NAD+ ratio are connected with the molecular process of the IAA response. The results demonstrate that IAA treatment is a stimulus capable of inducing changes in gene expression, enzyme activity and metabolite level involved in central metabolic pathways in E. coli.
Bianco
C
C
Institute of Genetics and Biophysics 'Adriano Buzzati Traverso', via P. Castellino 111, 80131 Naples, Italy.
Imperlini
E
E
Institute of Genetics and Biophysics 'Adriano Buzzati Traverso', via P. Castellino 111, 80131 Naples, Italy.
Calogero
R
R
Dipartimento di Scienze Cliniche e Biologiche, Ospedale S. Luigi, Regione Gonzole 10, Orbassano (TO), Italy.
Senatore
B
B
Institute of Genetics and Biophysics 'Adriano Buzzati Traverso', via P. Castellino 111, 80131 Naples, Italy.
Pucci
P
P
Dipartimento di Chimica Organica e Biochimica, Università Federico II di Napoli, Via Cinthia, 80126 Napoli, Italy.
Defez
R
R
Institute of Genetics and Biophysics 'Adriano Buzzati Traverso', via P. Castellino 111, 80131 Naples, Italy.
D000596:Amino Acids / Q000096:biosynthesis; D002244:Carbon / Q000378:metabolism; D002952:Citric Acid Cycle; D004734:Energy Metabolism; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism*; D020869:Gene Expression Profiling; D007210:Indoleacetic Acids / Q000494:pharmacology*; D009243:NAD / Q000096:biosynthesis; D016133:Polymerase Chain Reaction
D000596:Amino Acids; D007210:Indoleacetic Acids; D009243:NAD; C030737:indoleacetic acid; D002244:Carbon