Global Transcriptional Regulators Involved in Carbon, Nitrogen, Phosphorus, and Sulfur Metabolisms in Corynebacterium glutamicum

2020 ◽  
pp. 113-147
Author(s):  
Koichi Toyoda ◽  
Masayuki Inui
Keyword(s):  
Corynebacterium Glutamicum ◽  
Transcriptional Regulators ◽  
Nitrogen Phosphorus

scholarly journals The transcriptional regulators RamA and RamB are involved in the regulation of glycogen synthesis in Corynebacterium glutamicum

Microbiology ◽  
2010 ◽  
Vol 156 (4) ◽  
pp. 1256-1263 ◽  
Author(s):  
Gerd M. Seibold ◽  
Christian T. Hagmann ◽  
Melanie Schietzel ◽  
Denise Emer ◽  
Marc Auchter ◽  
...  
Keyword(s):  
Carbon Source ◽  
Corynebacterium Glutamicum ◽  
Transcriptional Control ◽  
Glycogen Content ◽  
Glycogen Synthase ◽  
Glycogen Synthesis ◽  
Dry Weight ◽  
Transcriptional Regulators ◽  
Negative Regulator

When grown in glucose-, fructose- or sucrose-containing medium, the amino acid producer Corynebacterium glutamicum transiently accumulates large amounts of glycogen (up to 10 % of its dry weight), whereas only a marginal amount of glycogen is formed during growth with acetate. This carbon-source-dependent regulation is at least partially due to transcriptional control of glgC, encoding ADP-glucose pyrophosphorylase, the first enzyme of glycogen synthesis from glucose-1-phosphate. Here, we have analysed a possible regulatory role for the transcriptional regulators RamA and RamB on glycogen content of the cells and on control of expression of glgC and of glgA, which encodes the second enzyme of glycogen synthesis, glycogen synthase. Determination of the glycogen content of RamA- and RamB-deficient C. glutamicum indicated that RamA and RamB influence glycogen synthesis positively and negatively, respectively. In accordance with the identification of putative RamA and RamB binding sites upstream of glgC and glgA, both regulators were found to bind specifically to the glgC–glgA intergenic promoter region. Promoter activity assays in wild-type and RamA- and RamB-deficient strains of C. glutamicum revealed that (i) RamA is a positive regulator of glgC and glgA, (ii) RamB is a negative regulator of glgA and (iii) neither RamA nor RamB alone is responsible for the carbon-source-dependent regulation of glycogen synthesis in C. glutamicum.

CosR is an oxidative stress sensing a MarR-type transcriptional repressor in Corynebacterium glutamicum

2018 ◽  
Vol 475 (24) ◽  
pp. 3979-3995 ◽  
Author(s):  
Meiru Si ◽  
Can Chen ◽  
Tao Su ◽  
Chengchuan Che ◽  
Shumin Yao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Corynebacterium Glutamicum ◽  
Stress Resistance ◽  
Disulfide Bonds ◽  
Function Analysis ◽  
Transcriptional Regulators ◽  
Quinone Oxidoreductase ◽  
Oxidative Stress Resistance ◽  
Stress Sensing ◽  
Promoter Dna

The MarR family is unique to both bacteria and archaea. The members of this family, one of the most prevalent families of transcriptional regulators in bacteria, enable bacteria to adapt to changing environmental conditions, such as the presence of antibiotics, toxic chemicals, or reactive oxygen species (ROS), mainly by thiol-disulfide switches. Although the genome of Corynebacterium glutamicum encodes a large number of the putative MarR-type transcriptional regulators, their physiological and biochemical functions have so far been limited to only two proteins, regulator of oxidative stress response RosR and quinone oxidoreductase regulator QosR. Here, we report that the ncgl2617 gene (cosR) of C. glutamicum encoding an MarR-type transcriptional regulator plays an important role in oxidative stress resistance. The cosR null mutant is found to be more resistant to various oxidants and antibiotics, accompanied by a decrease in ROS production and protein carbonylation levels under various stresses. Protein biochemical function analysis shows that two Cys residues presenting at 49 and 62 sites in CosR are redox-active. They form intermolecular disulfide bonds in CosR under oxidative stress. This CosR oxidation leads to its dissociation from promoter DNA, depression of the target DNA, and increased oxidative stress resistance of C. glutamicum. Together, the results reveal that CosR is a redox-sensitive regulator that senses peroxide stress to mediate oxidative stress resistance in C. glutamicum.

scholarly journals Regulation of Corynebacterium glutamicum Heat Shock Response by the Extracytoplasmic-Function Sigma Factor SigH and Transcriptional Regulators HspR and HrcA

2009 ◽  
Vol 191 (9) ◽  
pp. 2964-2972 ◽  
Author(s):  
Shigeki Ehira ◽  
Haruhiko Teramoto ◽  
Masayuki Inui ◽  
Hideaki Yukawa
Keyword(s):  
Heat Shock ◽  
Corynebacterium Glutamicum ◽  
Heat Shock Response ◽  
Sigma Factor ◽  
Transcription Initiation ◽  
Transcriptional Regulators ◽  
Shock Response ◽  
Genes Encoding ◽  
Hsp Genes ◽  
Extracytoplasmic Function Sigma Factor

ABSTRACT Heat shock response in Corynebacterium glutamicum was characterized by whole-genome expression analysis using a DNA microarray. It was indicated that heat shock response of C. glutamicum included not only upregulation of heat shock protein (HSP) genes encoding molecular chaperones and ATP-dependent proteases, but it also increased and decreased expression of more than 300 genes related to disparate physiological functions. An extracytoplasmic-function sigma factor, SigH, was upregulated by heat shock. The SigH regulon was defined by gene expression profiling using sigH-disrupted and overexpressing strains in conjunction with mapping of transcription initiation sites. A total of 45 genes, including HSP genes and genes involved in oxidative stress response, were identified as the SigH regulon. Expression of some HSP genes was also upregulated by deletion of the transcriptional regulators HspR and HrcA. HspR represses expression of the clpB and dnaK operons, and HrcA represses expression of groESL1 and groEL2. SigH was shown to play an important role in regulation of heat shock response in concert with HspR and HrcA, but its role is likely restricted to only a part of the regulation of C. glutamicum heat shock response. Upregulation of 18 genes encoding transcriptional regulators by heat shock suggests a complex regulatory network of heat shock response in C. glutamicum.

RamA and RamB are global transcriptional regulators in Corynebacterium glutamicum and control genes for enzymes of the central metabolism

2011 ◽  
Vol 154 (2-3) ◽  
pp. 126-139 ◽  
Author(s):  
Marc Auchter ◽  
Annette Cramer ◽  
Andrea Hüser ◽  
Christian Rückert ◽  
Denise Emer ◽  
...  
Keyword(s):  
Corynebacterium Glutamicum ◽  
Transcriptional Regulators ◽  
Central Metabolism ◽  
And Control

scholarly journals The DtxR Regulon of Corynebacterium glutamicum

2006 ◽  
Vol 188 (8) ◽  
pp. 2907-2918 ◽  
Author(s):  
Julia Wennerhold ◽  
Michael Bott
Keyword(s):  
Gene Expression ◽  
Corynebacterium Glutamicum ◽  
Dna Microarrays ◽  
Iron Acquisition ◽  
Mrna Level ◽  
Global Gene Expression ◽  
Transcriptional Regulators ◽  
Mrna Levels ◽  
Computer Based ◽  
Transcriptome Comparison

ABSTRACT Previous studies with Corynebacterium diphtheriae and Mycobacterium species revealed that the transcriptional regulator DtxR and its ortholog IdeR play a central role in the control of iron metabolism. In the present work, we used genome-based approaches to determine the DtxR regulon of Corynebacterium glutamicum, a nonpathogenic relative of C. diphtheriae. First, global gene expression of a dtxR deletion mutant was compared with that of the wild type using DNA microarrays. Second, we used a computer-based approach to identify 117 putative DtxR binding sites in the C. glutamicum genome. In the third step, 74 of the corresponding genome regions were amplified by PCR, 51 of which were shifted by the DtxR protein. Finally, we analyzed which of the genes preceded by a functional DtxR binding site showed altered mRNA levels in the transcriptome comparison. Fifty-one genes organized in 27 putative operons displayed an increased mRNA level in the ΔdtxR mutant and thus are presumably repressed by DtxR. The majority of these genes are obviously involved in iron acquisition, three encode transcriptional regulators, e.g., the recently identified repressor of iron proteins RipA, and the others encode proteins of diverse or unknown functions. Thirteen genes showed a decreased mRNA level in the ΔdtxR mutant and thus might be activated by DtxR. This group included the suf operon, whose products are involved in the formation and repair of iron-sulfur clusters, and several genes for transcriptional regulators. Our results clearly establish DtxR as the master regulator of iron-dependent gene expression in C. glutamicum.

scholarly journals Coordinated Regulation ofgnd, Which Encodes 6-Phosphogluconate Dehydrogenase, by the Two Transcriptional Regulators GntR1 and RamA in Corynebacterium glutamicum

2012 ◽  
Vol 194 (23) ◽  
pp. 6527-6536 ◽  
Author(s):  
Yuya Tanaka ◽  
Shigeki Ehira ◽  
Haruhiko Teramoto ◽  
Masayuki Inui ◽  
Hideaki Yukawa
Keyword(s):  
Dna Binding ◽  
Corynebacterium Glutamicum ◽  
Binding Sites ◽  
Affinity Purification ◽  
Transcriptional Start Site ◽  
Transcriptional Regulators ◽  
Binding Activity ◽  
Upstream Region ◽  
Content Type ◽  
Phosphogluconate Dehydrogenase

ABSTRACTThe transcriptional regulation ofCorynebacterium glutamicum gnd, encoding 6-phosphogluconate dehydrogenase, was investigated. Two transcriptional regulators, GntR1 and RamA, were isolated by affinity purification usinggndpromoter DNA. GntR1 was previously identified as a repressor of gluconate utilization genes, includinggnd. Involvement of RamA ingndexpression had not been investigated to date. The level ofgndmRNA was barely affected by the single deletion oframA. However,gndexpression was downregulated in theramA gntR1double mutant compared to that of thegntR1single mutant, suggesting that RamA activatesgndexpression. Two RamA binding sites are found in the 5′ upstream region ofgnd. Mutation proximal to the transcriptional start site diminished the gluconate-dependent induction ofgnd-lacZ. DNase I footprinting assay revealed two GntR1 binding sites, with one corresponding to a previously proposed site that overlaps with the −10 region. The other site overlaps the RamA binding site. GntR1 binding to this newly identified site inhibits DNA binding of RamA. Therefore, it is likely that GntR1 repressesgndexpression by preventing both RNA polymerase and RamA binding to the promoter. In addition, DNA binding activity of RamA was reduced by high concentrations of NAD(P)H but not by NAD(P), implying that RamA senses the redox perturbation of the cell.

Sign in / Sign up

Export Citation Format

Share Document