Dataset Information

Glucan Biosynthesis Protein G Is a Suitable Reference Gene in Escherichia coli K-12.

ABSTRACT: The expressions of reference genes used in gene expression studies are assumed to be stable under most circumstances. However, a number of studies had demonstrated that such genes were found to vary under experimental conditions. In addition, genes that are stably expressed in an organ may not be stably expressed in other organs or other organisms, suggesting the need to identify reference genes for each organ and organism. This study aims at identifying stably expressed genes in Escherichia coli. Microarray datasets from E. coli substrain MG1655 and 1 dataset from W3110 were analysed. Coefficient of variance (COV) of was calculated and 10% of the lowest COV from 4631 genes common in the 3 MG1655 sets were analysed using NormFinder. Glucan biosynthesis protein G (mdoG), which is involved in cell wall synthesis, displayed the lowest weighted COV and weighted NormFinder Stability Index for the MG1655 datasets, while also showing to be the most stable in the dataset for substrain W3110, suggesting that mdoG is a suitable reference gene for E. coli K-12. Gene ontology over-representation analysis on the 39 genes suggested an over-representation of cell division, carbohydrate metabolism, and protein synthesis which supports the short generation time of E. coli.

SUBMITTER: Heng SS

PROVIDER: S-EPMC3658596 | biostudies-literature | 2011

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Glucan Biosynthesis Protein G Is a Suitable Reference Gene in Escherichia coli K-12.

Heng Sean S J SS Chan Oliver Y W OY Keng Bryan M H BM Ling Maurice H T MH

ISRN microbiology 20111123

The expressions of reference genes used in gene expression studies are assumed to be stable under most circumstances. However, a number of studies had demonstrated that such genes were found to vary under experimental conditions. In addition, genes that are stably expressed in an organ may not be stably expressed in other organs or other organisms, suggesting the need to identify reference genes for each organ and organism. This study aims at identifying stably expressed genes in Escherichia col ...[more]

PMID: 23724305

Similar Datasets

Project description:Escherichia coli survives under acid stress conditions by the glutamic acid-dependent acid resistance (GAD) system, which enzymatically decreases intracellular protons. We found a linkage between GAD and flagellar systems in E. coli. The hdeD gene, one of the GAD cluster genes, encodes an uncharacterized membrane protein. A reporter assay showed that the hdeD promoter was induced in a GadE-dependent manner when grown in the M9 glycerol medium. Transcriptome analysis revealed that most of the transcripts were from genes involved in flagellum synthesis, and cell motility increased not only in the hdeD-deficient mutant but also in the gadE-deficient mutant. Defects in both the hdeD and gadE increased the intracellular level of FliA, an alternative sigma factor for flagellum synthesis, activated by the master regulator FlhDC. The promoter activity of the lrhA gene, which encodes repressor for the flhDC operon, was found to decrease in both the hdeD- and gadE-deficient mutants. Transmission electron microscopy showed that the number of flagellar filaments on the hdeD-, gadE-, and lrhA-deficient cells increased, and all three mutants showed higher motility than the parent strain. Thus, HdeD in the GAD system activates the lrhA promoter, resulting in a decrease in flagellar filaments in E. coli cells. We speculated that the synthesis of HdeD, stimulated in E. coli exposed to acid stress, could control the flagellum biosynthesis by sensing slight changes in pH at the cytoplasmic membrane. This could help in saving energy through termination of flagellum biosynthesis and improve bacterial survival efficiency within the animal digestive system. IMPORTANCE E. coli cells encounter various environments from the mouth down to the intestines within the host animals. The pH of gastric juice is lower than 2.0, and the bacterial must quickly respond and adapt to the following environmental changes before reaching the intestines. The quick response plays a role in cellular survival in the population, whereas adaptation may contribute to species survival. The GAD and flagellar systems are important for response to low pH in E. coli. Here, we identified the novel inner membrane regulator HdeD, encoding in the GAD cluster, to repress the synthesis of flagella. These insights provide a deeper understanding of how the bacteria enter the animal digestive system, survive, and form colonies in the intestines.

Dataset Information

Glucan Biosynthesis Protein G Is a Suitable Reference Gene in Escherichia coli K-12.

Publications

Glucan Biosynthesis Protein G Is a Suitable Reference Gene in Escherichia coli K-12.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets