Bacteria are extremely versatile organisms which rapidly adapt to changing environments. When Escherichia coli cells switch from planktonic growth to biofilm, flagellum formation is turned off, and the production of fimbriae and extracellular polysaccharides is switched on. Here we show that BolA protein is a new bacterial transcription factor which modulates the switch from planktonic to sessile lifestyle. BolA negatively modulates flagella biosynthesis and thus swimming capacity. Furthermore, BolA overexpression favors biofilm formation and involvesinvolving fimbriae-like adhesins and curli production. Our results unraveled for the first time that BolA is a protein with high affinity to DNA, involved in the regulation of several genes of E. coli at a genome-wide scale level. Moreover, this observation further demonstrated that the most significant targets of this protein involved a complex network of genes encoding proteins extremely necessary in biofilm development processes. Herein we propose that BolA is a motile/adhesive transcriptional switch, specifically involved in the transition between the planktonic and the attachment stage of biofilm formation process.
BolA is a transcriptional switch that turns off motility and turns on biofilm development.
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View SamplesBackground The RNA steady-state levels in the cell are a balance between synthesis and degradation rates. Although transcription is important, RNA processing and turnover are also key factors in the regulation of gene expression. In Escherichia coli there are three main exoribonucleases (RNase II, RNase R and PNPase) involved in RNA degradation. Although there are many studies about these exoribonucleases not much is known about their global effect in the transcriptome. Results In order to study the effects of the exoribonucleases on the transcriptome, we sequenced the total RNA (RNA-Seq) from wild-type cells and from mutants for each of the exoribonucleases (?rnb, ?rnr and ?pnp). We compared each of the mutant transcriptome with the wild-type to determine the global effects of the deletion of each exoribonucleases in exponential phase. We determined that the deletion of RNase II significantly affected 187 transcripts, while deletion of RNase R affects 202 transcripts and deletion of PNPase affected 226 transcripts. Surprisingly, many of the transcripts are actually down-regulated in the exoribonuclease mutants when compared to the wild-type control. The results obtained from the transcriptomic analysis pointed to the fact that these enzymes were changing the expression of genes related with flagellum assembly, motility and biofilm formation. The three exoribonucleases affected some stable RNAs, but PNPase was the main exoribonuclease affecting this class of RNAs. We confirmed by qPCR some fold-change values obtained from the RNA-Seq data, we also observed that all the exoribonuclease mutants were significantly less motile than the wild-type cells. Additionally, RNase II and RNase R mutants were shown to produce more biofilm than the wild-type control while the PNPase mutant did not form biofilms. Conclusions In this work we demonstrate how deep sequencing can be used to discover new and relevant functions of the exoribonucleases. We were able to obtain valuable information about the transcripts affected by each of the exoribonucleases and compare the roles of the three enzymes. Our results show that the three exoribonucleases affect cell motility and biofilm formation that are two very important factors for cell survival, especially for pathogenic cells. Overall design: RNA-Seq of E. coli K-12 MG1693 wild-type(wt) and three exoribonucleases mutants was done with Illumina Hi-Seq platform.
PNPase is involved in the coordination of mRNA degradation and expression in stationary phase cells of Escherichia coli.
Cell line, Subject
View SamplesHeterozygous and homozygous Pax2 E11.5 embryos were collected and the intermediate mesoderm was dissected and dispersed into single cells.
Evidence for intermediate mesoderm and kidney progenitor cell specification by Pax2 and PTIP dependent mechanisms.
Specimen part
View SamplesSperm cells of seed plants have lost their motility and are transported by the vegetative pollen tube cell for fertilization. The extent to which sperm cells regulate their own transportation is a long-standing debate. By using the novel Arabidopsis double mutant drop1 drop2, we demonstrate here that sperm cells are only passive cargo and that the vegetative tube cell as a vehicle controls the entire journey. Overall design: the semi-in-vivo pollen tubes of wild type (WT) and drop mutant using single-cell RNA sequencing
Sperm cells are passive cargo of the pollen tube in plant fertilization.
Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
CXCL10 is critical for the progression and maintenance of depigmentation in a mouse model of vitiligo.
Specimen part
View SamplesSkin samples from mice in a model of vitiligo were selected for gene expression profiling in order to identify active inflammatory pathways.
CXCL10 is critical for the progression and maintenance of depigmentation in a mouse model of vitiligo.
Specimen part
View SamplesLiver RNA was collected from three genotypes: WT controls, KCP knockout (KCP-KO) mutants, and KCP-Transgenic (KCP-Tg) overexpressing mice.
The kielin/chordin-like protein KCP attenuates nonalcoholic fatty liver disease in mice.
Specimen part
View SamplesGlomerular RNA comparison between wild-type and podocyte specific deletion of the PTIP gene in 1 month old kidneys. The PTIP gene was deleted using a floxed allele and a Podocin-Cre driver strain.
Altering a histone H3K4 methylation pathway in glomerular podocytes promotes a chronic disease phenotype.
Specimen part
View SamplesHuman skin samples from cutaneous lupus subtypes, psoriasis, and normal patients were used to corroborate findings of Fas Ligand elevation in a murine model of cutaneous lupus
Fas ligand promotes an inducible TLR-dependent model of cutaneous lupus-like inflammation.
Specimen part, Disease, Disease stage
View SamplesGene expression profiles of peripheral blood samples from C57BL/6 mice exposed with ionizing radiation.
Biological pathway selection through Bayesian integrative modeling.
Sex, Specimen part, Treatment, Time
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