Disease relevance of Regulon

• A number of cis- and trans-acting transcriptional factors in the flagellar regulons of Caulobacter crescentus and Salmonella typhimurium have been identified and characterized to varying degrees over the past year, bringing us closer to understanding the regulations of these complex gene hierarchies [1].
• We use this approach to analyze the purine (PurR), arginine (ArgR) and aromatic amino acid (TrpR and TyrR) regulons of Escherichia coli and Haemophilus influenzae [2].
• The global transcriptional response of Bacillus subtilis to manganese involves the MntR, Fur, TnrA and sigmaB regulons [3].
• The mechanism of induction of the maltose/maltodextrin regulon of the Gram-positive bacterium Streptococcus pneumoniae seems to be different to the positively controlled maltose regulons of the enteric bacteria Escherichia coli, Klebsiella pneumoniae and Salmonella typhimurium [4].
• These changes, among others, coincide with the upregulation of the chemotaxis and sensing regulons, of the lp38-encoded ABC transporter, of proteases capable of remodeling the outer surface of the spirochetes, and of the recombination genes of cp32 as a transient or initial part of the stress response of the phage [5].

High impact information on Regulon

• Here, we show that two potent negative regulators of Start, Sfp1 and Sch9, are activators of the ribosomal protein (RP) and ribosome biogenesis (Ribi) regulons, the transcriptional programs that dictate ribosome synthesis rate in accord with environmental and intracellular conditions [6].
• We propose that the sigma E regulon is involved in processes that occur in extracytoplasmic compartments and that these two heat-inducible regulons may have distinct but complementary roles of monitoring the state of proteins in the cytoplasm (sigma 32) and outer membrane (sigma E) [7].
• We have shown previously that RAD9 also controls the transcriptional induction of a DNA damage regulon (DDR) [8].
• The presence and versatility of transport systems encoded by beta-ketoadipate pathway regulons is just beginning to be explored in various microbial groups [9].
• Acetosyringone (AS) induced the expression of all known members of the vir regulons, as well as a small number of additional genes [10].

Chemical compound and disease context of Regulon

• The cysteine regulons of Salmonella typhimurium and Escherichia coli are positively regulated by CysB protein and either O-acetyl-L-serine or N-acetyl-L-serine, both of which act as inducers [11].
• The cysPTWA operons of Escherichia coli and Salmonella typhimurium encode components of periplasmic transport systems for sulfate and thiosulfate and are regulated as part of the cysteine regulons [12].
• The components and their organization in the dha regulon of these two organisms differ considerably from each other and also from the previously partially sequenced dha regulons in Citrobacter freundii, Clostridium pasteurianum, and Clostridium butyricum [13].
• Potential new members of the xylose regulons were found in the Escherichia coli, Salmonella typhi, and Klebsiella pneumoniae genomes [14].

Biological context of Regulon

• Yap1 and Skn7 control two specialized oxidative stress response regulons in yeast [15].
• Antitermination of transcription mediated by proteins interacting with mRNA sequences is described for nine operons/regulons [16].
• D-fructose, an intracellular product of sucrose transport and hydrolysis, and D-fructose 1-phosphate were shown to be molecular inducers of both scr regulons [17].
• Hexameric arginine repressor, ArgR, bound to L-arginine serves both as the master transcriptional repressor/activator at diverse regulons in a wide range of bacteria and as a required cofactor for resolution of ColE1 plasmid multimers [18].
• The mutant protein L62R was unable to complex with Ssn6 or repress expression of reporter genes for the hypoxic and glucose repressed regulons or the flocculence phenotype, however, expression of the a-mating type reporter gene was still repressed [19].

Anatomical context of Regulon

• This study shows that exposure of S. typhimurium to sublethal concentrations of CAMP activates the PhoP/PhoQ and RpoS virulence regulons, while repressing the transcription of genes required for flagella synthesis and the invasion-associated type III secretion system [20].

Associations of Regulon with chemical compounds

• Many of these genes were members of the cAMP-cAMP receptor protein (CRP) and guanosine tetraphosphate (ppGpp) regulons [21].
• Rather, the improvement in glucose scavenging involves induction of genes in 2 distinct regulons (mgl/gal and mal/lamB) through synthesis of 2 different endogenous inducer molecules (galactose, maltotriose) [22].
• We found that the absence of heme, due to a deletion in the gene that encodes delta-aminolevulinic acid synthase (HEM1), resulted in decreased transcription of genes belonging to both the iron and copper regulons, but not the zinc regulon [23].
• Our findings provide further evidence for important functions of the PbuE protein, such as acting as a pump that lowers the purine base pool and affects the expression of the G-box and PurR regulons, including pbuE itself, and as a pump involved in protection against toxic purine base analogs [24].
• Thus, we conclude that the lowered concentration of cAMP in cyaA mutants induces both sigma E and Cpx extracytoplasmic stress regulons and thereby rescues the degP temperature-sensitive phenotype [25].

Gene context of Regulon

• Transcript profiling revealed minimal overlap between the Ssn6 and Tup1 regulons [26].
• We examined the in vivo expression of up to 16 genes encoding for components of both glutaredoxin and thioredoxin systems and for members of the OxyR and SoxRS regulons [27].
• Mutations in the sirA orthologs of Escherichia coli, Vibrio cholerae, Pseudomonas fluorescens, and Pseudomonas aeruginosa result in defects in either motility or motility gene regulation, suggesting that control of flagellar regulons may be an evolutionarily conserved function of sirA orthologs [28].
• Our comparison of the Gcn4 and Gcn2 regulons by transcript profiling reinforces the view that Gcn2 contributes to, but is not essential for, the activation of general amino acid control in C. albicans [29].
• Heat and various inhibitory chemicals were tested in Escherichia coli for the ability to cause accumulation of adenylylated nucleotides and to induce proteins of the heat shock (htpR-controlled), the oxidation stress (oxyR-controlled), and the SOS (lexA-controlled) regulons [30].

References