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DNA binding of the cell cycle transcriptional regulator GcrA depends on N6-adenosine methylation in Caulobacter crescentus and other Alphaproteobacteria |
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Published in | PLOS genetics. 2013, vol. 9, no. 5, e1003541 | |
Abstract | Several regulators are involved in the control of cell cycle progression in the bacterial model system Caulobacter crescentus, which divides asymmetrically into a vegetative G1-phase (swarmer) cell and a replicative S-phase (stalked) cell. Here we report a novel functional interaction between the enigmatic cell cycle regulator GcrA and the N6-adenosine methyltransferase CcrM, both highly conserved proteins among Alphaproteobacteria, that are activated early and at the end of S-phase, respectively. As no direct biochemical and regulatory relationship between GcrA and CcrM were known, we used a combination of ChIP (chromatin-immunoprecipitation), biochemical and biophysical experimentation, and genetics to show that GcrA is a dimeric DNA-binding protein that preferentially targets promoters harbouring CcrM methylation sites. After tracing CcrM-dependent N6-methyl-adenosine promoter marks at a genome-wide scale, we show that these marks recruit GcrA in vitro and in vivo. Moreover, we found that, in the presence of a methylated target, GcrA recruits the RNA polymerase to the promoter, consistent with its role in transcriptional activation. Since methylation-dependent DNA binding is also observed with GcrA orthologs from other Alphaproteobacteria, we conclude that GcrA is the founding member of a new and conserved class of transcriptional regulators that function as molecular effectors of a methylation-dependent (non-heritable) epigenetic switch that regulates gene expression during the cell cycle. | |
Keywords | Adenosine/genetics — Alphaproteobacteria/growth & development — Amino Acid Sequence — Caulobacter crescentus/genetics/growth & development — Cell Cycle Proteins/genetics/metabolism — DNA Methylation/genetics — DNA-Binding Proteins/genetics — Epigenesis, Genetic — Gene Expression Regulation, Bacterial — Methyltransferases/genetics/metabolism — Promoter Regions, Genetic — Transcription, Genetic | |
Identifiers | PMID: 23737758 | |
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Research group | Régulation du cycle cellulaire dans C.crescentus, une bactérie asymétrique (895) | |
Citation (ISO format) | FIORAVANTI, Antonella et al. DNA binding of the cell cycle transcriptional regulator GcrA depends on N6-adenosine methylation in Caulobacter crescentus and other Alphaproteobacteria. In: PLOS genetics, 2013, vol. 9, n° 5, p. e1003541. doi: 10.1371/journal.pgen.1003541 https://archive-ouverte.unige.ch/unige:32604 |