scholarly journals Enhanced Production of Polymyxin E in Paenibacillus polymyxa by Replacement of Glucose by Starch

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Zhiliang Yu ◽  
Zhongqi Sun ◽  
Jianhua Yin ◽  
Juanping Qiu
Keyword(s):  
Regulatory Gene ◽  
Protein A ◽  
Paenibacillus Polymyxa ◽  
Fermentation Medium ◽  
Transcriptional Level ◽  
Relative Expression Level ◽  
Enhanced Production ◽  
Expression Of Genes ◽  
Catabolite Control Protein A ◽  
Polymyxin E

Polymyxin E or colistin, produced by Paenibacillus polymyxa, is an important antibiotic against Gram-negative pathogens. The objective of this study is to evaluate the effect of starch in fermentation medium on colistin biosynthesis in P. polymyxa. The results indicated that replacement of glucose by starch stimulated colistin production and biosynthesis rate. Overall, the stimulation extent was starch concentration-dependent. As expected, addition of starch induced the expression of amyE encoding amylase and increased amylase activity in fermentation solution. Additionally, replacement of glucose by starch resulted in residue reducing sugar and pH of fermentation mixture low relative to glucose as the sole sugar source. At the molecular level, it was found that replacement of glucose by starch has enhanced the relative expression level of ccpA encoding catabolite control protein A. Therefore, the repression of starch utilization by glucose could be probably relieved. In addition, use of starch stimulated the expression of regulatory gene spo0A but repressed the expression of another regulatory gene abrB. As a result, the expression of genes directly involved in colistin biosynthesis and secretion increased, indicating that at the transcriptional level spo0A and abrB played opposite roles in regulating colistin biosynthesis in P. polymyxa. Taken together, our data demonstrated that starch instead of glucose can promote colistin production probably by affecting the expression of colistin biosynthesis-related genes, as well as reducing the repression of glucose to a secondary metabolic product.

scholarly journals Precursor Amino Acids Inhibit Polymyxin E Biosynthesis inPaenibacillus polymyxa, Probably by Affecting the Expression of Polymyxin E Biosynthesis-Associated Genes

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Zhiliang Yu ◽  
Chenglin Guo ◽  
Juanping Qiu
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Paenibacillus Polymyxa ◽  
Regulatory Genes ◽  
Obvious Effect ◽  
Diaminobutyric Acid ◽  
Expression Of Genes ◽  
Genes Expression ◽  
Polypeptide Antibiotic ◽  
Polymyxin E

Polymyxin E belongs to cationic polypeptide antibiotic bearing four types of direct precursor amino acids including L-2,4-diaminobutyric acid (L-Dab), L-Leu, D-Leu, and L-Thr. The objective of this study is to evaluate the effect of addition of precursor amino acids during fermentation on polymyxin E biosynthesis inPaenibacillus polymyxa. The results showed that, after 35 h fermentation, addition of direct precursor amino acids to certain concentration significantly inhibited polymyxin E production and affected the expression of genes involved in its biosynthesis. L-Dab repressed the expression of polymyxin synthetase genespmxAandpmxE, as well as 2,4-diaminobutyrate aminotransferase geneectB; both L-Leu and D-Leu repressed thepmxAexpression. In addition, L-Thr affected the expression of not onlypmxA, but also regulatory genesspo0AandabrB. As L-Dab precursor, L-Asp repressed the expression ofectB,pmxA, andpmxE. Moreover, it affected the expression ofspo0AandabrB. In contrast, L-Phe, a nonprecursor amino acid, had no obvious effect on polymyxin E biosynthesis and those biosynthesis-related genes expression. Taken together, our data demonstrated that addition of precursor amino acids during fermentation will inhibit polymyxin E production probably by affecting the expression of its biosynthesis-related genes.

Characterization of a Tn551-mutant of Staphylococcus aureus defective in the production of several exoproteins

1994 ◽  
Vol 40 (8) ◽  
pp. 677-681 ◽  
Author(s):  
Ana T. Giraudo ◽  
Claudia G. Raspanti ◽  
Aldo Calzolari ◽  
Rosa Nagel
Keyword(s):  
Staphylococcus Aureus ◽  
Regulatory Gene ◽  
Blot Hybridization ◽  
Protein A ◽  
Southern Blot Hybridization ◽  
Terminal Segment ◽  
Transcriptional Level ◽  
Extracellular Form ◽  
Single Insertion

A Tn551 insertional pleiotropic mutant defective in the production of several exoproteins was isolated from Staphylococcus aureus 196E and characterized. The pleiotropism of the mutant was due to a single insertion of the transposon as evidenced by Southern blot hybridization and by the transfer of its phenotype by transduction to S. aureus ISP479. The mutants showed diminished or null levels of α- and β-hemolysins, DNase, coagulase, and protein A in the supernatants of broth cultures. Production of proteases, lipase, staphylokinase, or enterotoxin A was not modified. The mutants did synthesize the cell-bound form of protein A and also the extracellular form of this protein coded by pRIT11, which lacks the COOH-terminal segment of the molecule. These observations suggest that the sae locus does not involve a positive regulatory gene acting at the transcriptional level. The phenotype of the mutant was different from that of other insertional mutants affecting exoprotein synthesis, such as agr, xpr, or sar. This new mutation has been designated sae (for S. aureus exoprotein expression).Key words: S. aureus, transpositional mutant, exoprotein production, pleiotropism, protein A.

scholarly journals NtbHLH1, a JAF13-like bHLH, interacts with NtMYB6 to enhance proanthocyanidin accumulation in Chinese Narcissus

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuxin Fan ◽  
Jiayu Peng ◽  
Jiacheng Wu ◽  
Ping Zhou ◽  
Ruijie He ◽  
...  
Keyword(s):  
Flavonoid Biosynthesis ◽  
Transcriptional Level ◽  
Flavonoid Pathway ◽  
Regulation Of Expression ◽  
Over Expression ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Regulatory Complex ◽  
Positive Regulators ◽  
R2r3 Myb

Abstract Background Flavonoid biosynthesis in plants is primarily regulated at the transcriptional level by transcription factors modulating the expression of genes encoding enzymes in the flavonoid pathway. One of the most studied transcription factor complexes involved in this regulation consists of a MYB, bHLH and WD40. However, in Chinese Narcissus (Narcissus tazetta L. var. chinensis), a popular monocot bulb flower, the regulatory mechanism of flavonoid biosynthesis remains unclear. Results In this work, genes related to the regulatory complex, NtbHLH1 and a R2R3-MYB NtMYB6, were cloned from Chinese Narcissus. Phylogenetic analysis indicated that NtbHLH1 belongs to the JAF13 clade of bHLH IIIf subgroup, while NtMYB6 was highly homologous to positive regulators of proanthocyanidin biosynthesis. Both NtbHLH1 and NtMYB6 have highest expression levels in basal plates of Narcissus, where there is an accumulation of proanthocyanidin. Ectopic over expression of NtbHLH1 in tobacco resulted in an increase in anthocyanin accumulation in flowers, and an up-regulation of expression of the endogenous tobacco bHLH AN1 and flavonoid biosynthesis genes. In contrast, the expression level of LAR gene was significantly increased in NtMYB6-transgenic tobacco. Dual luciferase assays showed that co-infiltration of NtbHLH1 and NtMYB6 significantly activated the promoter of Chinese Narcissus DFR gene. Furthermore, a yeast two-hybrid assay confirmed that NtbHLH1 interacts with NtMYB6. Conclusions Our results suggest that NtbHLH1 may function as a regulatory partner by interacting directly with NtMYB6 to enhance proanthocyanidin accumulation in Chinese Narcissus.

scholarly journals Interactional mechanisms of Paenibacillus polymyxa SC2 and pepper (Capsicum annuum L.) suggested by transcriptomics

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hu Liu ◽  
Yufei Li ◽  
Ke Ge ◽  
Binghai Du ◽  
Kai Liu ◽  
...  
Keyword(s):  
Capsicum Annuum ◽  
Biofilm Formation ◽  
Rhizosphere Soil ◽  
Paenibacillus Polymyxa ◽  
Systemic Resistance ◽  
Expression Of Genes ◽  
Transcription Factor Genes ◽  
Transcription Regulators ◽  
Relationship Of ◽  
Stimulation Of

Abstract Background Paenibacillus polymyxa SC2, a bacterium isolated from the rhizosphere soil of pepper (Capsicum annuum L.), promotes growth and biocontrol of pepper. However, the mechanisms of interaction between P. polymyxa SC2 and pepper have not yet been elucidated. This study aimed to investigate the interactional relationship of P. polymyxa SC2 and pepper using transcriptomics. Results P. polymyxa SC2 promotes growth of pepper stems and leaves in pot experiments in the greenhouse. Under interaction conditions, peppers stimulate the expression of genes related to quorum sensing, chemotaxis, and biofilm formation in P. polymyxa SC2. Peppers induced the expression of polymyxin and fusaricidin biosynthesis genes in P. polymyxa SC2, and these genes were up-regulated 2.93- to 6.13-fold and 2.77- to 7.88-fold, respectively. Under the stimulation of medium which has been used to culture pepper, the bacteriostatic diameter of P. polymyxa SC2 against Xanthomonas citri increased significantly. Concurrently, under the stimulation of P. polymyxa SC2, expression of transcription factor genes WRKY2 and WRKY40 in pepper was up-regulated 1.17-fold and 3.5-fold, respectively. Conclusions Through the interaction with pepper, the ability of P. polymyxa SC2 to inhibit pathogens was enhanced. P. polymyxa SC2 also induces systemic resistance in pepper by stimulating expression of corresponding transcription regulators. Furthermore, pepper has effects on chemotaxis and biofilm formation of P. polymyxa SC2. This study provides a basis for studying interactional mechanisms of P. polymyxa SC2 and pepper.

Control of the glycolytic gapA operon by the catabolite control protein A in Bacillus subtilis: a novel mechanism of CcpA-mediated regulation

2002 ◽  
Vol 45 (2) ◽  
pp. 543-553 ◽  
Author(s):  
Holger Ludwig ◽  
Nicole Rebhan ◽  
Hans-Matti Blencke ◽  
Matthias Merzbacher ◽  
Jorg Stulke
Keyword(s):  
Bacillus Subtilis ◽  
Protein A ◽  
Catabolite Control Protein A ◽  
Control Protein ◽  
Catabolite Control

Drugs used to treat bipolar disorder act via microRNAs to regulate expression of genes involved in neurite outgrowth

2020 ◽  
Vol 34 (3) ◽  
pp. 370-379 ◽  
Author(s):  
Srisaiyini Kidnapillai ◽  
Ben Wade ◽  
Chiara C Bortolasci ◽  
Bruna Panizzutti ◽  
Briana Spolding ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
Neurite Outgrowth ◽  
Neural Plasticity ◽  
Drug Combination ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Drug Effects ◽  
Differentially Expressed ◽  
Transcriptional Level ◽  
Expression Of Genes

Background: The drugs commonly used to treat bipolar disorder have limited efficacy and drug discovery is hampered by the paucity of knowledge of the pathophysiology of this disease. This study aims to explore the role of microRNAs in bipolar disorder and understand the molecular mechanisms of action of commonly used bipolar disorder drugs. Methods: The transcriptional effects of bipolar disorder drug combination (lithium, valproate, lamotrigine and quetiapine) in cultured human neuronal cells were studied using next generation sequencing. Differential expression of genes ( n=20) and microRNAs ( n=6) was assessed and the differentially expressed microRNAs were confirmed with TaqMan MicroRNA Assays. The expression of the differentially expressed microRNAs were inhibited to determine bipolar disorder drug effects on their target genes ( n=8). Independent samples t-test was used for normally distributed data and Kruskal-Wallis/Mann-Whitney U test was used for data not distributed normally. Significance levels were set at p<0.05. Results: We found that bipolar disorder drugs tended to increase the expression of miR-128 and miR-378 ( p<0.05). Putative target genes of these microRNAs targeted pathways including those identified as “neuron projection development” and “axonogenesis”. Many of the target genes are inhibitors of neurite outgrowth and neurogenesis and were downregulated following bipolar disorder drug combination treatment (all p<0.05). The bipolar disorder drug combination tended to decrease the expression of the target genes ( NOVA1, GRIN3A, and VIM), however this effect could be reversed by the application of microRNA inhibitors. Conclusions: We conclude that at a transcriptional level, bipolar disorder drugs affect several genes in concert that would increase neurite outgrowth and neurogenesis and hence neural plasticity, and that this effect is mediated (at least in part) by modulation of the expression of these two key microRNAs.

scholarly journals Dal81 Regulates Expression of Arginine Metabolism Genes inCandida parapsilosis

mSphere ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Siobhan A. Turner ◽  
Qinxi Ma ◽  
Mihaela Ola ◽  
Kontxi Martinez de San Vicente ◽  
Geraldine Butler
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Pathogenic Fungus ◽  
Nitrogen Sources ◽  
Nitrogen Utilization ◽  
Nitrogen Regulation ◽  
Transcriptional Level ◽  
Pathogenic Yeast ◽  
Secondary Sources ◽  
Expression Of Genes ◽  
Maximal Induction

ABSTRACTFungi can use a wide variety of nitrogen sources. In the absence of preferred sources such as ammonium, glutamate, and glutamine, secondary sources, including most other amino acids, are used. Expression of the nitrogen utilization pathways is very strongly controlled at the transcriptional level. Here, we investigated the regulation of nitrogen utilization in the pathogenic yeastCandida parapsilosis. We found that the functions of many regulators are conserved with respect toSaccharomyces cerevisiaeand other fungi. For example, the core GATA activatorsGAT1andGLN3have a conserved role innitrogencataboliterepression (NCR). There is one ortholog ofGZF3andDAL80, which represses expression of genes in preferred nitrogen sources. The regulatorsPUT3andUGA3are required for metabolism of proline and γ-aminobutyric acid (GABA), respectively. However, the role of the Dal81 transcription factor is distinctly different. InS. cerevisiae, Dal81 is a positive regulator of acquisition of nitrogen from GABA, allantoin, urea, and leucine, and it is required for maximal induction of expression of the relevant pathway genes. InC. parapsilosis, induction of GABA genes is independent of Dal81, and deletingDAL81has no effect on acquisition of nitrogen from GABA or allantoin. Instead, Dal81 represses arginine synthesis during growth under preferred nitrogen conditions.IMPORTANCEUtilization of nitrogen by fungi is controlled bynitrogencataboliterepression (NCR). Expression of many genes is switched off during growth on nonpreferred nitrogen sources. Gene expression is regulated through a combination of activation and repression. Nitrogen regulation has been studied best in the model yeastSaccharomyces cerevisiae. We found that although many nitrogen regulators have a conserved function inSaccharomycesspecies, some do not. The Dal81 transcriptional regulator has distinctly different functions inS. cerevisiaeandC. parapsilosis. In the former, it regulates utilization of nitrogen from GABA and allantoin, whereas in the latter, it regulates expression of arginine synthesis genes. Our findings make an important contribution to our understanding of nitrogen regulation in a human-pathogenic fungus.

scholarly journals The impact of Paenibacillus polymyxa HY96-2 luxS on biofilm formation and control of tomato bacterial wilt

2019 ◽  
Vol 103 (23-24) ◽  
pp. 9643-9657 ◽  
Author(s):  
Jincui Yi ◽  
Daojing Zhang ◽  
Yuejuan Cheng ◽  
Jingjing Tan ◽  
Yuanchan Luo
Keyword(s):  
Bacterial Wilt ◽  
Late Stage ◽  
Biofilm Formation ◽  
Early Stage ◽  
Regulatory Gene ◽  
Paenibacillus Polymyxa ◽  
Deletion Strain ◽  
Biocontrol Efficacy ◽  
The Impact ◽  
Tomato Bacterial Wilt

Abstract The focus of this study was to investigate the effects of luxS, a key regulatory gene of the autoinducer-2 (AI-2) quorum sensing (QS) system, on the biofilm formation and biocontrol efficacy against Ralstonia solanacearum by Paenibacillus polymyxa HY96-2. luxS mutants were constructed and assayed for biofilm formation of the wild-type (WT) strain and luxS mutants of P. polymyxa HY96-2 in vitro and in vivo. The results showed that luxS positively regulated the biofilm formation of HY96-2. Greenhouse experiments of tomato bacterial wilt found that from the early stage to late stage postinoculation, the biocontrol efficacy of the luxS deletion strain was the lowest with 50.70 ± 1.39% in the late stage. However, the luxS overexpression strain had the highest biocontrol efficacy with 75.66 ± 1.94% in the late stage. The complementation of luxS could restore the biocontrol efficacy of the luxS deletion strain with 69.84 ± 1.09% in the late stage, which was higher than that of the WT strain with 65.94 ± 2.73%. Therefore, we deduced that luxS could promote the biofilm formation of P. polymyxa HY96-2 and further promoted its biocontrol efficacy against R. solanacearum.

scholarly journals Carcinogen-induced trans activation of gene expression.

1988 ◽  
Vol 8 (3) ◽  
pp. 1366-1370 ◽  
Author(s):  
T Kleinberger ◽  
Y B Flint ◽  
M Blank ◽  
S Etkin ◽  
S Lavi
Keyword(s):  
Gene Expression ◽  
Transcriptional Level ◽  
Expression Of Genes ◽  
Cellular Factors

We report a new mechanism of carcinogen action by which the expression of several genes was concomitantly enhanced. This mechanism involved the altered activity of cellular factors which modulate the expression of genes under their control. The increased expression was regulated at least in part on the transcriptional level and did not require amplification of the overexpressed genes. This phenomenon was transient; it was apparent as early as 24 h after carcinogen treatment and declined a few days later.

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