Limits...
Gene regulation by H-NS as a function of growth conditions depends on chromosomal position in Escherichia coli.

Brambilla E, Sclavi B - G3 (Bethesda) (2015)

Bottom Line: Cellular adaptation to changing environmental conditions requires the coordinated regulation of expression of large sets of genes by global regulatory factors such as nucleoid associated proteins.Our results show that the activity of the Phns promoter depends on whether it is placed within the AT-rich regions of the genome that are known to be bound preferentially by H-NS.Genomic position can thus play a significant role in the adaptation of the cells to environmental changes, providing a fitness advantage that can explain the selection of a gene's position during evolution.

View Article: PubMed Central - PubMed

Affiliation: LBPA, UMR 8113 du CNRS, Ecole Normale Supérieure de Cachan, Cachan, France School of Engineering and Science, Jacobs University Bremen, Bremen, Germany.

Show MeSH

Related in: MedlinePlus

The difference in YFP concentration is larger at lower temperature and in the transition to stationary phase. The protein concentration was normalized by the LT values for strains in exponential, entry into stationary, and stationary phase (CAA05 at 30°) for three independent experiments, the error bar corresponds to the SEM. Data were taken at the time of maximum growth rate, at the time where the growth rate was half of the maximum and at growth rate equal to zero, respectively. The difference between YFP concentration in LO and RO strains arises at the entry into stationary phase. This is not observed when the experiment is carried out at 37° (see Figure S3). In stationary phase, the difference in protein concentration for all the positions decreases. The protein concentration for the LT strain is always lower than in the other strains. LM, left medium; LO, left origin; LT, left terminus; RM, right medium; RO, right origin; RT, right terminus; YFP, yellow fluorescent protein.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4390576&req=5

fig4: The difference in YFP concentration is larger at lower temperature and in the transition to stationary phase. The protein concentration was normalized by the LT values for strains in exponential, entry into stationary, and stationary phase (CAA05 at 30°) for three independent experiments, the error bar corresponds to the SEM. Data were taken at the time of maximum growth rate, at the time where the growth rate was half of the maximum and at growth rate equal to zero, respectively. The difference between YFP concentration in LO and RO strains arises at the entry into stationary phase. This is not observed when the experiment is carried out at 37° (see Figure S3). In stationary phase, the difference in protein concentration for all the positions decreases. The protein concentration for the LT strain is always lower than in the other strains. LM, left medium; LO, left origin; LT, left terminus; RM, right medium; RO, right origin; RT, right terminus; YFP, yellow fluorescent protein.

Mentions: For most of the sites, comparison of YFP concentration as a function of genomic position in exponential phase shows a difference between the sites that can be explained by the differences in gene copy number expected from the DNA replication process (Figure 3). Interestingly, there is also a difference in gene expression between the sites that are equidistant from the origin, notably between left terminus (LT) and right terminus (RT) and right origin (RO) and left origin (LO). The latter difference becomes evident especially at slow growth and upon entry into stationary phase (Figure 3 and Figure 4).


Gene regulation by H-NS as a function of growth conditions depends on chromosomal position in Escherichia coli.

Brambilla E, Sclavi B - G3 (Bethesda) (2015)

The difference in YFP concentration is larger at lower temperature and in the transition to stationary phase. The protein concentration was normalized by the LT values for strains in exponential, entry into stationary, and stationary phase (CAA05 at 30°) for three independent experiments, the error bar corresponds to the SEM. Data were taken at the time of maximum growth rate, at the time where the growth rate was half of the maximum and at growth rate equal to zero, respectively. The difference between YFP concentration in LO and RO strains arises at the entry into stationary phase. This is not observed when the experiment is carried out at 37° (see Figure S3). In stationary phase, the difference in protein concentration for all the positions decreases. The protein concentration for the LT strain is always lower than in the other strains. LM, left medium; LO, left origin; LT, left terminus; RM, right medium; RO, right origin; RT, right terminus; YFP, yellow fluorescent protein.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390576&req=5

fig4: The difference in YFP concentration is larger at lower temperature and in the transition to stationary phase. The protein concentration was normalized by the LT values for strains in exponential, entry into stationary, and stationary phase (CAA05 at 30°) for three independent experiments, the error bar corresponds to the SEM. Data were taken at the time of maximum growth rate, at the time where the growth rate was half of the maximum and at growth rate equal to zero, respectively. The difference between YFP concentration in LO and RO strains arises at the entry into stationary phase. This is not observed when the experiment is carried out at 37° (see Figure S3). In stationary phase, the difference in protein concentration for all the positions decreases. The protein concentration for the LT strain is always lower than in the other strains. LM, left medium; LO, left origin; LT, left terminus; RM, right medium; RO, right origin; RT, right terminus; YFP, yellow fluorescent protein.
Mentions: For most of the sites, comparison of YFP concentration as a function of genomic position in exponential phase shows a difference between the sites that can be explained by the differences in gene copy number expected from the DNA replication process (Figure 3). Interestingly, there is also a difference in gene expression between the sites that are equidistant from the origin, notably between left terminus (LT) and right terminus (RT) and right origin (RO) and left origin (LO). The latter difference becomes evident especially at slow growth and upon entry into stationary phase (Figure 3 and Figure 4).

Bottom Line: Cellular adaptation to changing environmental conditions requires the coordinated regulation of expression of large sets of genes by global regulatory factors such as nucleoid associated proteins.Our results show that the activity of the Phns promoter depends on whether it is placed within the AT-rich regions of the genome that are known to be bound preferentially by H-NS.Genomic position can thus play a significant role in the adaptation of the cells to environmental changes, providing a fitness advantage that can explain the selection of a gene's position during evolution.

View Article: PubMed Central - PubMed

Affiliation: LBPA, UMR 8113 du CNRS, Ecole Normale Supérieure de Cachan, Cachan, France School of Engineering and Science, Jacobs University Bremen, Bremen, Germany.

Show MeSH
Related in: MedlinePlus