scholarly journals The YtrBCDEF ABC transporter is involved in the control of social activities in Bacillus subtilis

2020 ◽  
Author(s):  
Martin Benda ◽  
Lisa Schulz ◽  
Jeanine Rismondo ◽  
Jörg Stülke
Keyword(s):  
Cell Wall ◽  
Transcription Factor ◽  
Bacillus Subtilis ◽  
Abc Transporter ◽  
Biofilm Formation ◽  
Translational Regulation ◽  
Constitutive Expression ◽  
Competence Development ◽  
Dna Uptake ◽  
Genetic Competence

AbstractBacillus subtilis develops genetic competence for the uptake of foreign DNA when cells enter the stationary phase and a high cell density is reached. These signals are integrated by the competence transcription factor ComK which is subject to transcriptional, post-transcriptional and post-translational regulation. Many proteins are involved in the development of competence, both to control ComK activity and to mediate DNA uptake. However, the precise function they play in competence development is often unknown. In this study, we have tested whether proteins required for genetic transformation play a role in the activation of ComK or rather downstream of competence gene expression. While these possibilities could be distinguished for most of the tested factors, two proteins (PNPase and the transcription factor YtrA) are required both for full ComK activity and for the downstream processes of DNA uptake and integration. Further analyses of the role of the transcription factor YtrA for the competence development revealed that the constitutive expression of the YtrBCDEF ABC transporter in the ytrA mutant causes the loss of genetic competence. Moreover, constitutive expression of this ABC transporter also interferes with biofilm formation. Since the ytrGABCDEF operon is induced by cell wall-targeting antibiotics, we tested the cell wall properties upon overexpression of the ABC transporter and observed an increased thickness of the cell wall. The composition and properties of the cell wall are important for competence development and biofilm formation, suggesting that the increased cell wall thickness as a result of YtrBCDEF overexpression causes the observed phenotypes.

scholarly journals Influence of the ABC Transporter YtrBCDEF of Bacillus subtilis on Competence, Biofilm Formation and Cell Wall Thickness

2021 ◽  
Vol 12 ◽  
Author(s):  
Martin Benda ◽  
Lisa Maria Schulz ◽  
Jörg Stülke ◽  
Jeanine Rismondo
Keyword(s):  
Cell Wall ◽  
Transcription Factor ◽  
Bacillus Subtilis ◽  
Abc Transporter ◽  
Wall Thickness ◽  
Biofilm Formation ◽  
Competence Development ◽  
Cell Wall Thickness ◽  
Dna Uptake ◽  
Genetic Competence

Bacillus subtilis develops genetic competence for the uptake of foreign DNA when cells enter stationary phase and a high cell density is reached. These signals are integrated by the competence transcription factor ComK, which is subject to transcriptional, post-transcriptional and post-translational regulation. Many proteins are involved in the development of competence, both to control ComK activity and to mediate DNA uptake. However, for many proteins, the precise function they play in competence development is unknown. In this study, we assessed whether proteins required for genetic transformation play a role in the activation of ComK or rather act downstream of competence gene expression. While these possibilities could be distinguished for most of the tested factors, we assume that two proteins, PNPase and the transcription factor YtrA, are required both for full ComK activity and for the downstream processes of DNA uptake and integration. Further analyses of the role of the transcription factor YtrA for the competence development revealed that the overexpression of the YtrBCDEF ABC transporter in the ytrA mutant causes the loss of genetic competence. Moreover, overexpression of this ABC transporter also affects biofilm formation. Since the ytrGABCDEF operon is naturally induced by cell wall-targeting antibiotics, we tested the cell wall properties upon overexpression of the ABC transporter and observed an increased thickness of the cell wall. The composition and properties of the cell wall are important for competence development and biofilm formation, suggesting that the observed phenotypes are the result of the increased cell wall thickness as an outcome of YtrBCDEF overexpression.

scholarly journals The Transcription Factor SomA Synchronously Regulates Biofilm Formation and Cell Wall Homeostasis in Aspergillus fumigatus

mBio ◽  
2020 ◽  
Vol 11 (6) ◽  
Author(s):  
Yuan Chen ◽  
Francois Le Mauff ◽  
Yan Wang ◽  
Ruiyang Lu ◽  
Donald C. Sheppard ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcription Factor ◽  
Aspergillus Fumigatus ◽  
Biofilm Formation ◽  
Wall Stress ◽  
Fungal Cell ◽  
Glucan Synthase ◽  
Content Type ◽  
Cell Wall Stress ◽  
Chitin Synthases

ABSTRACT Polysaccharides are key components of both the fungal cell wall and biofilm matrix. Despite having distinct assembly and regulation pathways, matrix exopolysaccharide and cell wall polysaccharides share common substrates and intermediates in their biosynthetic pathways. It is not clear, however, if the biosynthetic pathways governing the production of these polysaccharides are cooperatively regulated. Here, we demonstrate that cell wall stress promotes production of the exopolysaccharide galactosaminogalactan (GAG)-depend biofilm formation in the major fungal pathogen of humans Aspergillus fumigatus and that the transcription factor SomA plays a crucial role in mediating this process. A core set of SomA target genes were identified by transcriptome sequencing and chromatin immunoprecipitation coupled to sequencing (ChIP-Seq). We identified a novel SomA-binding site in the promoter regions of GAG biosynthetic genes agd3 and ega3, as well as its regulators medA and stuA. Strikingly, this SomA-binding site was also found in the upstream regions of genes encoding the cell wall stress sensors, chitin synthases, and β-1,3-glucan synthase. Thus, SomA plays a direct regulation of both GAG and cell wall polysaccharide biosynthesis. Consistent with these findings, SomA is required for the maintenance of normal cell wall architecture and compositions in addition to its function in biofilm development. Moreover, SomA was found to globally regulate glucose uptake and utilization, as well as amino sugar and nucleotide sugar metabolism, which provides precursors for polysaccharide synthesis. Collectively, our work provides insight into fungal adaptive mechanisms in response to cell wall stress where biofilm formation and cell wall homeostasis were synchronously regulated. IMPORTANCE The cell wall is essential for fungal viability and is absent from human hosts; thus, drugs disrupting cell wall biosynthesis have gained more attention. Caspofungin is a member of a new class of clinically approved echinocandin drugs to treat invasive aspergillosis by blocking β-1,3-glucan synthase, thus damaging the fungal cell wall. Here, we demonstrate that caspofungin and other cell wall stressors can induce galactosaminogalactan (GAG)-dependent biofilm formation in the human pathogen Aspergillus fumigatus. We further identified SomA as a master transcription factor playing a dual role in both biofilm formation and cell wall homeostasis. SomA plays this dual role by direct binding to a conserved motif upstream of GAG biosynthetic genes and genes involved in cell wall stress sensors, chitin synthases, and β-1,3-glucan synthase. Collectively, these findings reveal a transcriptional control pathway that integrates biofilm formation and cell wall homeostasis and suggest SomA as an attractive target for antifungal drug development.

scholarly journals RelA Protein Is Involved in Induction of Genetic Competence in Certain Bacillus subtilis Strains by Moderating the Level of Intracellular GTP

2002 ◽  
Vol 184 (14) ◽  
pp. 3923-3930 ◽  
Author(s):  
Takashi Inaoka ◽  
Kozo Ochi
Keyword(s):  
Bacillus Subtilis ◽  
High Performance ◽  
Stationary Growth Phase ◽  
Competence Development ◽  
Stationary Growth ◽  
Transcriptional Fusion ◽  
Auxotrophic Strain ◽  
Genetic Competence ◽  
Physiological Conditions ◽  
Fusion Analysis

ABSTRACT We found that the ability to develop genetic competence of a certain relaxed (relA) aspartate-auxotrophic strain of Bacillus subtilis is significantly lower than that of the isogenic stringent (relA +) strain. Transcriptional fusion analysis utilizing a lacZ reporter gene indicated that the amount of the ComK protein, known as the key protein for competence development, is greatly reduced in the relaxed strain than in the stringent strain. We also found that the addition of decoyinine, a GMP synthetase inhibitor, induces expression of a competence gene (comG) in the relaxed strain, accompanied by a pronounced decrease in the level of intracellular GTP as measured by high-performance liquid chromatography. The transformation efficiency of the relaxed strain increased 100-fold when decoyinine was added at t0 (the transition point between exponential to stationary growth phase). Conversely, supplementation of guanosine together with decoyinine completely abolished the observed effect of adding decoyinine on competence development. Furthermore, the impaired ability of the relaxed strain for competence development was completely restored by disrupting the codY gene, which is known to negatively control comK expression. Our results indicate that the RelA protein plays an essential role in the induction of competence development at least under certain physiological conditions by reducing the level of intracellular GTP and overcoming CodY-mediated regulation.

scholarly journals Synergistic Regulation of Competence Development in Bacillus subtilis by Two Rap-Phr Systems

2005 ◽  
Vol 187 (13) ◽  
pp. 4353-4361 ◽  
Author(s):  
Cristina Bongiorni ◽  
Shu Ishikawa ◽  
Sophie Stephenson ◽  
Naotake Ogasawara ◽  
Marta Perego
Keyword(s):  
Transcription Factor ◽  
Bacillus Subtilis ◽  
Response Regulator ◽  
Specific Binding ◽  
Competence Development ◽  
Target Dna ◽  
Synergistic Regulation ◽  
Dna Promoters ◽  
Carboxy Terminal ◽  
Encoding Genes

ABSTRACT The 11 Rap proteins of Bacillus subtilis comprise a conserved family of tetratricopeptide (TPR)-containing regulatory proteins. Their activity is inhibited by specific Phr pentapeptides produced from the product of phr genes through an export-import maturation process. We found that one of the proteins, namely RapF, is involved in the regulation of competence to DNA transformation. The ComA response regulator and transcription factor for initiation of competence development is the target of RapF. Specific binding of RapF to the carboxy-terminal DNA-binding domain of ComA inhibits the response regulator's ability to bind its target DNA promoters. The PhrF C-terminal pentapeptide, QRGMI, inhibits RapF activity. The activity of RapF and PhrF in regulating competence development is analogous to the previously described activity of RapC and PhrC (L. J. Core and M. Perego, Mol. Microbiol. 49:1509-1522, 2003). In fact, the RapF and PhrF pair of proteins acts synergistically with RapC and PhrC in the overall regulation of the ComA transcription factor. Since the transcription of the RapC- and RapF-encoding genes is positively regulated by their own target ComA, an autoregulatory circuit must exist for the competence transcription factor in order to modulate its activity.

scholarly journals Natural Genetic Competence in Bacillus subtilis Natto OK2

2000 ◽  
Vol 182 (9) ◽  
pp. 2411-2415 ◽  
Author(s):  
Sayaka Ashikaga ◽  
Hideaki Nanamiya ◽  
Yoshiaki Ohashi ◽  
Fujio Kawamura
Keyword(s):  
Bacillus Subtilis ◽  
Base Change ◽  
Competence Development ◽  
Transformation Frequency ◽  
Genetic Competence ◽  
Natural Competence ◽  
Bacillus Subtilis Natto ◽  
High Transformation ◽  
Single Base Change ◽  
Natural Genetic Competence

ABSTRACT We isolated a Bacillus subtilis natto strain, designated OK2, from a lot of commercial fermented soybean natto and studied its ability to undergo natural competence development using acomG-lacZ fusion at the amyE locus. Although transcription of the late competence genes was not detected in theB. subtilis natto strain OK2 during competence development, these genes were constitutively transcribed in the OK2 strain carrying either the mecA or the clpC mutation derived from B. subtilis 168. In addition, both OK2 mutants exhibited high transformation frequencies, comparable with that observed for B. subtilis 168. Moreover, as expected from these results, overproduction of ComK derived from strain 168 in strain OK2 resulted in a high transformation frequency as well as in induction of the late competence genes. These results clearly indicated that ComK produced in both the mecA and clpC mutants of strain OK2 (ComKOK2) could activate the transcription of the whole set of late competence genes and suggested that ComKOK2 was not activated in strain OK2 during competence development. We therefore sequenced the comS gene of OK2 and compared it with that of 168. The comS OK2had a single-base change, resulting in the replacement of Ser (strain 168) by Cys (strain OK2) at position 11.

comK encodes the competence transcription factor, the key regulatory protein for competence development in Bacillus subtilis

1995 ◽  
Vol 15 (3) ◽  
pp. 455-462 ◽  
Author(s):  
Douwe Sinderen ◽  
Amy Luttinger ◽  
Liyun Kong ◽  
David Dubnau ◽  
Gerard Venema ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Bacillus Subtilis ◽  
Regulatory Protein ◽  
Competence Development

scholarly journals Structural characterization of the late competence protein ComFB from Bacillus subtilis

2015 ◽  
Vol 35 (2) ◽  
Author(s):  
Tatyana A. Sysoeva ◽  
Lukas B. Bane ◽  
Daphne Y. Xiao ◽  
Baundauna Bose ◽  
Scott S. Chilton ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Structural Characterization ◽  
Competence Development ◽  
Regulatory Role ◽  
In Vivo Studies ◽  
Genetic Competence

Development of genetic competence in Bacillus subtilis results in expression of late competence genes, including comFB. In vitro and in vivo studies revealed that ComFB dimerizes, binds zinc, and possibly plays a regulatory role in competence development.

Bacillus subtilis YqjG is required for genetic competence development

PROTEOMICS ◽  
2010 ◽  
Vol 11 (2) ◽  
pp. 270-282 ◽  
Author(s):  
Manfred J. Saller ◽  
Andreas Otto ◽  
Greetje A. Berrelkamp-Lahpor ◽  
Dörte Becher ◽  
Michael Hecker ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Competence Development ◽  
Genetic Competence

scholarly journals Negative Interplay between Biofilm Formation and Competence in the Environmental Strains of Bacillus subtilis

mSystems ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Qianxuan She ◽  
Evan Hunter ◽  
Yuxuan Qin ◽  
Samantha Nicolau ◽  
Eliza A. Zalis ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Cell Differentiation ◽  
Biofilm Formation ◽  
Competence Development ◽  
Bacterial Biofilm ◽  
Soil Bacterium ◽  
Natural Competence ◽  
Content Type ◽  
Pathway Regulation

The soil bacterium Bacillus subtilis can form robust biofilms, which are important for its survival in the environment. B. subtilis also exhibits natural competence. By investigating competence development in B. subtilis in situ during biofilm formation, we reveal that robust biofilm formation often greatly reduces the frequency of competent cells within the biofilm. We then characterize a cross-pathway regulation that allows cells in these two developmental events to undergo mutually exclusive cell differentiation during biofilm formation. Finally, we discuss potential biological implications of limiting competence in a bacterial biofilm.

scholarly journals Unravelling the genetic basis for competence development of auxotrophic Bacillus licheniformis 9945A strains

Microbiology ◽  
2014 ◽  
Vol 160 (10) ◽  
pp. 2136-2147 ◽  
Author(s):  
Mareike Jakobs ◽  
Kerstin Hoffmann ◽  
Anja Grabke ◽  
Stefania Neuber ◽  
Heiko Liesegang ◽  
...  
Keyword(s):  
Bacillus Licheniformis ◽  
Extracellular Enzymes ◽  
Random Mutagenesis ◽  
Extracellular Enzyme ◽  
Competence Development ◽  
Colony Morphology ◽  
Enzyme Secretion ◽  
Dna Uptake ◽  
Genetic Competence ◽  
Regulator Genes

Bacterial natural genetic competence – well studied in Bacillus subtilis – enables cells to take up and integrate extracellularly supplied DNA into their own genome. However, little is known about competence development and its regulation in other members of the genus, although DNA uptake machineries are routinely encoded. Auxotrophic Bacillus licheniformis 9945A derivatives, obtained from repeated rounds of random mutagenesis, were long known to develop natural competence. Inspection of the colony morphology and extracellular enzyme secretion of two of these derivatives, M28 and M18, suggested that regulator genes are collaterally hit. M28 emerged as a 14 bp deletion mutant concomitantly displaying a shift in the reading frame of degS that encodes the sensor histidine kinase, which is part of the molecular switch that directs cells to genetic competence, the synthesis of extracellular enzymes or biofilm formation, while for M18, sequencing of the suspected gene revealed a 375 bp deletion in abrB, encoding the major transition state regulator. With respect to colony morphology, enzyme secretion and competence development, both of the mutations, when newly generated on the wild-type B. licheniformis 9945A genetic background, resulted in phenotypes resembling M28 and M18, respectively. All of the known naturally competent B. licheniformis representatives, hitherto thoroughly investigated in this regard, carry mutations in regulator genes, and hence genetic competence observed in domesticated strains supposedly results from deregulation.

Sign in / Sign up

Export Citation Format

Share Document