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MioC and GidA proteins promote cell division in E. coli.

Lies M, Visser BJ, Joshi MC, Magnan D, Bates D - Front Microbiol (2015)

Bottom Line: The well-conserved genes surrounding the E. coli replication origin, mioC and gidA, do not normally affect chromosome replication and have little known function.Cell elongation is exacerbated by a fis deletion, likely owing to delayed replication and subsequent cell cycle stress.Measurements of replication initiation frequency and origin segregation indicate that mioC and gidA do not inhibit cell division through any effect on oriC function.

View Article: PubMed Central - PubMed

Affiliation: Molecular and Human Genetics, Baylor College of Medicine Houston, TX, USA.

ABSTRACT
The well-conserved genes surrounding the E. coli replication origin, mioC and gidA, do not normally affect chromosome replication and have little known function. We report that mioC and gidA mutants exhibit a moderate cell division inhibition phenotype. Cell elongation is exacerbated by a fis deletion, likely owing to delayed replication and subsequent cell cycle stress. Measurements of replication initiation frequency and origin segregation indicate that mioC and gidA do not inhibit cell division through any effect on oriC function. Division inhibition is also independent of the two known replication/cell division checkpoints, SOS and nucleoid occlusion. Complementation analysis indicates that mioC and gidA affect cell division in trans, indicating their effect is at the protein level. Transcriptome analysis by RNA sequencing showed that expression of a cell division septum component, YmgF, is significantly altered in mioC and gidA mutants. Our data reveal new roles for the gene products of gidA and mioC in the division apparatus, and we propose that their expression, cyclically regulated by chromatin remodeling at oriC, is part of a cell cycle regulatory program coordinating replication initiation and cell division.

No MeSH data available.


Related in: MedlinePlus

Transcription profiling inmioCandgidAmutants. (A,B) Changes in gene expression across the E. coli genome in mioC(A) and gidA(B) promoter mutants relative to wildtype was determined by RNA sequencing (Materials and Methods). Blue and red ticks indicated positive or negative fold-changes of individual genes. The positions of mioC and gidA, and a strongly affected cell division gene, ymgF, are indicated. See Table S3 for description of other affected genes. (C,D) The cell elongation phenotype of gidA and mioC mutants requires YmgF. Cell length was measured in exponentially growing wildtype and mioC and gidA promoter mutants in fis+(C) or fis−(D) genetic background, in the presence (black bars) or absence (gray bars) of a ymgFΔ mutation.
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Figure 6: Transcription profiling inmioCandgidAmutants. (A,B) Changes in gene expression across the E. coli genome in mioC(A) and gidA(B) promoter mutants relative to wildtype was determined by RNA sequencing (Materials and Methods). Blue and red ticks indicated positive or negative fold-changes of individual genes. The positions of mioC and gidA, and a strongly affected cell division gene, ymgF, are indicated. See Table S3 for description of other affected genes. (C,D) The cell elongation phenotype of gidA and mioC mutants requires YmgF. Cell length was measured in exponentially growing wildtype and mioC and gidA promoter mutants in fis+(C) or fis−(D) genetic background, in the presence (black bars) or absence (gray bars) of a ymgFΔ mutation.

Mentions: Although neither MioC nor GidA are known to regulate transcription, both have been implicated in information transfer functions (Introduction) and it is possible that mutants have altered expression of one or more cell division-related genes. To test this, we measured the relative abundance of all the E. coli mRNAs in wild-type and PmioC and PgidA single mutant strains by next-generation RNA sequencing. Both mutants had several up-regulated and several down-regulated genes as shown by high and low ticks, with each tick representing a single gene (Figures 6A,B). Altered genes included various ontology groups including amino acid and carbon metabolism, transcription, membrane proteins, and small molecule transport (Table S3). One gene in particular, ymgF, was significantly under-expressed (3.3-fold less than wt) in the PmioC mutant and over-expressed (3.1-fold more than wt) in the PgidA mutant (Figures 6A,B, arrows). This gene was previously identified in a bacterial two-hybrid screen for factors that interact with the division septum component FtsL (Karimova et al., 2009). GFP-tagged YmgF localizes strongly to the division septum, and although a ymgF deletion does not confer a growth or cell division phenotype, overexpression of YmgF suppresses a temperature-sensitive ftsQ mutant (Karimova et al., 2009). YmgF is a 72 amino acid integral membrane protein, but little else is known about its function.


MioC and GidA proteins promote cell division in E. coli.

Lies M, Visser BJ, Joshi MC, Magnan D, Bates D - Front Microbiol (2015)

Transcription profiling inmioCandgidAmutants. (A,B) Changes in gene expression across the E. coli genome in mioC(A) and gidA(B) promoter mutants relative to wildtype was determined by RNA sequencing (Materials and Methods). Blue and red ticks indicated positive or negative fold-changes of individual genes. The positions of mioC and gidA, and a strongly affected cell division gene, ymgF, are indicated. See Table S3 for description of other affected genes. (C,D) The cell elongation phenotype of gidA and mioC mutants requires YmgF. Cell length was measured in exponentially growing wildtype and mioC and gidA promoter mutants in fis+(C) or fis−(D) genetic background, in the presence (black bars) or absence (gray bars) of a ymgFΔ mutation.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4446571&req=5

Figure 6: Transcription profiling inmioCandgidAmutants. (A,B) Changes in gene expression across the E. coli genome in mioC(A) and gidA(B) promoter mutants relative to wildtype was determined by RNA sequencing (Materials and Methods). Blue and red ticks indicated positive or negative fold-changes of individual genes. The positions of mioC and gidA, and a strongly affected cell division gene, ymgF, are indicated. See Table S3 for description of other affected genes. (C,D) The cell elongation phenotype of gidA and mioC mutants requires YmgF. Cell length was measured in exponentially growing wildtype and mioC and gidA promoter mutants in fis+(C) or fis−(D) genetic background, in the presence (black bars) or absence (gray bars) of a ymgFΔ mutation.
Mentions: Although neither MioC nor GidA are known to regulate transcription, both have been implicated in information transfer functions (Introduction) and it is possible that mutants have altered expression of one or more cell division-related genes. To test this, we measured the relative abundance of all the E. coli mRNAs in wild-type and PmioC and PgidA single mutant strains by next-generation RNA sequencing. Both mutants had several up-regulated and several down-regulated genes as shown by high and low ticks, with each tick representing a single gene (Figures 6A,B). Altered genes included various ontology groups including amino acid and carbon metabolism, transcription, membrane proteins, and small molecule transport (Table S3). One gene in particular, ymgF, was significantly under-expressed (3.3-fold less than wt) in the PmioC mutant and over-expressed (3.1-fold more than wt) in the PgidA mutant (Figures 6A,B, arrows). This gene was previously identified in a bacterial two-hybrid screen for factors that interact with the division septum component FtsL (Karimova et al., 2009). GFP-tagged YmgF localizes strongly to the division septum, and although a ymgF deletion does not confer a growth or cell division phenotype, overexpression of YmgF suppresses a temperature-sensitive ftsQ mutant (Karimova et al., 2009). YmgF is a 72 amino acid integral membrane protein, but little else is known about its function.

Bottom Line: The well-conserved genes surrounding the E. coli replication origin, mioC and gidA, do not normally affect chromosome replication and have little known function.Cell elongation is exacerbated by a fis deletion, likely owing to delayed replication and subsequent cell cycle stress.Measurements of replication initiation frequency and origin segregation indicate that mioC and gidA do not inhibit cell division through any effect on oriC function.

View Article: PubMed Central - PubMed

Affiliation: Molecular and Human Genetics, Baylor College of Medicine Houston, TX, USA.

ABSTRACT
The well-conserved genes surrounding the E. coli replication origin, mioC and gidA, do not normally affect chromosome replication and have little known function. We report that mioC and gidA mutants exhibit a moderate cell division inhibition phenotype. Cell elongation is exacerbated by a fis deletion, likely owing to delayed replication and subsequent cell cycle stress. Measurements of replication initiation frequency and origin segregation indicate that mioC and gidA do not inhibit cell division through any effect on oriC function. Division inhibition is also independent of the two known replication/cell division checkpoints, SOS and nucleoid occlusion. Complementation analysis indicates that mioC and gidA affect cell division in trans, indicating their effect is at the protein level. Transcriptome analysis by RNA sequencing showed that expression of a cell division septum component, YmgF, is significantly altered in mioC and gidA mutants. Our data reveal new roles for the gene products of gidA and mioC in the division apparatus, and we propose that their expression, cyclically regulated by chromatin remodeling at oriC, is part of a cell cycle regulatory program coordinating replication initiation and cell division.

No MeSH data available.


Related in: MedlinePlus