scholarly journals A Small Cysteine-Free Protein Acts as a Novel Regulator of Fungal Insect-Pathogenic Lifecycle and Genomic Expression

mSystems ◽  
2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Ya-Ni Mou ◽  
Bo Fu ◽  
Kang Ren ◽  
Sheng-Hua Ying ◽  
Ming-Guang Feng
Keyword(s):  
Transcription Factors ◽  
Life Cycle ◽  
Pathogenic Fungi ◽  
Binding Activity ◽  
Secreted Proteins ◽  
Content Type ◽  
Genomic Expression ◽  
Free Protein ◽  
Dna Binding Activity ◽  
Virulence Effectors

ABSTRACT Small secreted proteins (SSPs), particularly cysteine-rich proteins secreted during fungal infection, comprise virulence effectors in plant-pathogenic fungi but remain unknown in insect-pathogenic fungi. We report here that only a small cysteine-free protein (CFP) is indispensable for insect pathogenicity of Beauveria bassiana among 10 studied SSPs (99 to 274 amino acids [aa]), including seven hypothetical proteins containing 0 to 12 Cys residues. CFP (120 aa) features an N-terminal signal peptide (residues 1 to 17), a nuclear localization signal motif (residues 24 to 57), and no predictable domain. Its homologs exist exclusively in insect-pathogenic Cordycipitaceae and Clavicipitaceae. Fluorescence-tagged CFP fusion protein was localized in the nucleus but extracellularly undetectable, suggesting an inability for CFP to be secreted out. Disruption of cfp resulted in abolished pathogenicity via normal cuticle infection, attenuated virulence via hemocoel injection, compromised conidiation capacity versus little growth defect, impaired conidial coat, blocked secretion of cuticle-degrading enzymes, impeded proliferation in vivo, disturbed cell cycle, reduced stress tolerance, and 1,818 dysregulated genes (genomic 17.54%). Hundreds of those genes correlated with phenotypic changes observed in the disruption mutant. Intriguingly, nearly 40% of those dysregulated genes encode hypothetical or unknown proteins, and another 13% encode transcription factors and enzymes or proteins collectively involved in genome-wide gene regulation. However, purified CFP showed no DNA-binding activity in an electrophoretic mobility shift assay. These findings unveil that CFP is a novel regulator of fungal insect-pathogenic life cycle and genomic expression and that cysteine richness is dispensable for distinguishing virulence effectors from putative SSPs in B. bassiana. IMPORTANCE Small cysteine-rich proteins secreted during plant-pathogenic fungal infection comprise virulence effectors. Our study confirms that only a cysteine-free protein (CFP) is determinant to insect-pathogenic fungal virulence among 10 small putatively secreted proteins containing 0 to 12 Cys residues. Disruption of cfp abolished insect pathogenicity and caused not only a series of compromised cellular events associated with host infection and disease development but also dysregulation of 1,818 genes, although no DNA-binding activity was detected in purified CFP samples. Nearly 13% of those genes encode transcription factors and enzymes or proteins collectively involved in transcriptional regulation. Altogether, CFP serves as a novel regulator of the fungal insect-pathogenic life cycle and genomic expression. Cysteine richness is dispensable for distinguishing virulence effectors from the fungal SSPs.

scholarly journals WblAch, a Pivotal Activator of Natamycin Biosynthesis and Morphological Differentiation in Streptomyces chattanoogensis L10, Is Positively Regulated by AdpAch

2014 ◽  
Vol 80 (22) ◽  
pp. 6879-6887 ◽  
Author(s):  
Pin Yu ◽  
Shui-Ping Liu ◽  
Qing-Ting Bu ◽  
Zhen-Xing Zhou ◽  
Zhen-Hong Zhu ◽  
...  
Keyword(s):  
Morphological Differentiation ◽  
Binding Activity ◽  
Transcriptional Analysis ◽  
Antibiotic Biosynthesis ◽  
Content Type ◽  
Real Time Quantitative Pcr ◽  
Dna Binding Activity ◽  
In The Wild ◽  
Natamycin Production ◽  
Streptomyces Chattanoogensis

ABSTRACTDetailed mechanisms ofWhiB-like (Wbl) proteins involved in antibiotic biosynthesis and morphological differentiation are poorly understood. Here, we characterize the role of WblAch, aStreptomyces chattanoogensisL10 protein belonging to this superfamily. Based on DNA microarray data and verified by real-time quantitative PCR (qRT-PCR), the expression ofwblAchwas shown to be positively regulated by AdpAch. Gel retardation assays and DNase I footprinting experiments showed that AdpAchhas specific DNA-binding activity for the promoter region ofwblAch. Gene disruption and genetic complementation revealed that WblAchacts in a positive manner to regulate natamycin production. WhenwblAchwas overexpressed in the wild-type strain, the natamycin yield was increased by ∼30%. This provides a strategy to generate improved strains for natamycin production. Moreover, transcriptional analysis showed that the expression levels ofwhigenes (includingwhiA,whiB,whiH, andwhiI) were severely depressed in the ΔwblAchmutant, suggesting that WblAchplays a part in morphological differentiation by influencing the expression of thewhigenes.

scholarly journals Direct inhibition of the DNA-binding activity of POU transcription factors Pit-1 and Brn-3 by selective binding of a phenyl-furan-benzimidazole dication

2008 ◽  
Vol 36 (10) ◽  
pp. 3341-3353 ◽  
Author(s):  
Paul Peixoto ◽  
Yang Liu ◽  
Sabine Depauw ◽  
Marie-Paule Hildebrand ◽  
David W. Boykin ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Dna Binding ◽  
Binding Activity ◽  
Direct Inhibition ◽  
Selective Binding ◽  
Dna Binding Activity

scholarly journals Toll-Like Receptor Stimulation Induces Nondefensin Protein Expression and Reverses Antibiotic-Induced Gut Defense Impairment

2014 ◽  
Vol 82 (5) ◽  
pp. 1994-2005 ◽  
Author(s):  
Ying-Ying Wu ◽  
Ching-Mei Hsu ◽  
Pei-Hsuan Chen ◽  
Chang-Phone Fung ◽  
Lee-Wei Chen
Keyword(s):  
Dna Binding ◽  
Protein Expression ◽  
Antibiotic Treatment ◽  
Intestinal Mucosa ◽  
Pathogenic Bacteria ◽  
Binding Activity ◽  
Toll Like Receptor ◽  
Content Type ◽  
Killing Activity ◽  
Dna Binding Activity

ABSTRACTPrior antibiotic exposure is associated with increased mortality in Gram-negative bacteria-induced sepsis. However, how antibiotic-mediated changes of commensal bacteria promote the spread of enteric pathogenic bacteria in patients remains unclear. In this study, the effects of systemic antibiotic treatment with or without Toll-like receptor (TLR) stimulation on bacterium-killing activity, antibacterial protein expression in the intestinal mucosa, and bacterial translocation were examined in mice receiving antibiotics with or without oral supplementation of deadEscherichia coliorStaphylococcus aureus. We developed a systemic ampicillin, vancomycin, and metronidazole treatment protocol to simulate the clinical use of antibiotics. Antibiotic treatment decreased the total number of bacteria, including aerobic bacteria belonging to the familyEnterobacteriaceaeand the genusEnterococcusas well as organisms of the anaerobic generaLactococcusandBifidobacteriumin the intestinal mucosa and lumen. Antibiotic treatment significantly decreased the bacterium-killing activity of the intestinal mucosa and the expression of non-defensin-family proteins, such as RegIIIβ, RegIIIγ, C-reactive protein-ductin, and RELMβ, but not the defensin-family proteins, and increasedKlebsiella pneumoniaetranslocation. TLR stimulation after antibiotic treatment increased NF-κB DNA binding activity, nondefensin protein expression, and bacterium-killing activity in the intestinal mucosa and decreasedK. pneumoniaetranslocation. Moreover, germfree mice showed a significant decrease in nondefensin proteins as well as intestinal defense against pathogen translocation. Since TLR stimulation induced NF-κB DNA binding activity, TLR4 expression, and mucosal bacterium-killing activity in germfree mice, we conclude that the commensal microflora is critical in maintaining intestinal nondefensin protein expression and the intestinal barrier. In turn, we suggest that TLR stimulation induces nondefensin protein expression and reverses antibiotic-induced gut defense impairment.

scholarly journals Free Fatty Acids Interfere with the DNA Binding Activity of the Virulence Regulator PrfA of Listeria monocytogenes

2020 ◽  
Vol 202 (15) ◽  
Author(s):  
Patrícia T. dos Santos ◽  
Rikke S. S. Thomasen ◽  
Mathias S. Green ◽  
Nils J. Færgeman ◽  
Birgitte H. Kallipolitis
Keyword(s):  
Fatty Acids ◽  
Dna Binding ◽  
Free Fatty Acids ◽  
Antimicrobial Agents ◽  
Virulence Gene ◽  
Binding Activity ◽  
Content Type ◽  
Dna Binding Activity ◽  
Virulence Regulator ◽  
Long Chain

ABSTRACT Naturally occurring free fatty acids (FFAs) are recognized as potent antimicrobial agents that also affect the production of virulence factors in bacterial pathogens. In the foodborne pathogen Listeria monocytogenes, some medium- and long-chain FFAs act as antimicrobial agents as well as signaling compounds, causing a repression of transcription of virulence genes. We previously observed that the master virulence regulator PrfA is involved in both the antimicrobial and virulence-inhibitory response of L. monocytogenes to selected FFAs, but the underlying mechanisms are presently unknown. Here, we present a systematic analysis of the antimicrobial and PrfA-inhibitory activities of medium- and long-chain FFAs of various carbon chain lengths and degrees of saturation. We observed that exposure to specific antimicrobial and nonantimicrobial FFAs prevented PrfA-dependent activation of virulence gene transcription and reduced the levels of PrfA-regulated virulence factors. Thus, an antimicrobial activity was not compulsory for the PrfA-inhibitory ability of an FFA. In vitro binding experiments revealed that PrfA-inhibitory FFAs were also able to prevent the constitutively active variant PrfA* from binding to the PrfA box in the promoter region of the virulence gene hly, whereas noninhibitory FFAs did not affect its ability to bind DNA. Notably, the unsaturated FFAs inhibited the DNA binding activity of PrfA* most efficiently. Altogether, our findings support a model in which specific FFAs orchestrate a generalized reduction of the virulence potential of L. monocytogenes by directly targeting the key virulence regulator PrfA. IMPORTANCE Listeria monocytogenes is a Gram-positive pathogen able to cause foodborne infections in humans and animals. Key virulence genes in L. monocytogenes are activated by the transcription regulator PrfA, a DNA binding protein belonging to the CRP/FNR family. Various signals from the environment are known to affect the activity of PrfA, either positively or negatively. Recently, we found that specific medium- and long-chain free fatty acids act as antimicrobial agents as well as signaling compounds in L. monocytogenes. Here, we show that both antimicrobial and nonantimicrobial free fatty acids inhibit PrfA-dependent activation of virulence gene transcription by interfering with the DNA binding activity of PrfA. Our findings suggest that free fatty acids could be candidates for alternative therapies against L. monocytogenes.

scholarly journals Fitting Pieces into the Puzzle ofPseudomonas aeruginosaType III Secretion System Gene Expression

2019 ◽  
Vol 201 (13) ◽  
Author(s):  
Emily A. Williams McMackin ◽  
Louise Djapgne ◽  
Jodi M. Corley ◽  
Timothy L. Yahr
Keyword(s):  
Gene Expression ◽  
Protein Delivery ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Activity ◽  
Secretion Systems ◽  
Content Type ◽  
Global Regulators ◽  
Dna Binding Activity ◽  
Host Pathogen

ABSTRACTType III secretion systems (T3SS) are widely distributed in Gram-negative microorganisms and critical for host-pathogen and host-symbiont interactions with plants and animals. Central features of the T3SS are a highly conserved set of secretion and translocation genes and contact dependence wherein host-pathogen interactions trigger effector protein delivery and serve as an inducing signal for T3SS gene expression. In addition to these conserved features, there are pathogen-specific properties that include a unique repertoire of effector genes and mechanisms to control T3SS gene expression. ThePseudomonas aeruginosaT3SS serves as a model system to understand transcriptional and posttranscriptional mechanisms involved in the control of T3SS gene expression. The central regulatory feature is a partner-switching system that controls the DNA-binding activity of ExsA, the primary regulator of T3SS gene expression. Superimposed upon the partner-switching mechanism are cyclic AMP and cyclic di-GMP signaling systems, two-component systems, global regulators, and RNA-binding proteins that have positive and negative effects on ExsA transcription and/or synthesis. In the present review, we discuss advances in our understanding of how these regulatory systems orchestrate the activation of T3SS gene expression in the context of acute infections and repression of the T3SS asP. aeruginosaadapts to and colonizes the cystic fibrosis airways.

Ozone-induced IL-8 expression and transcription factor binding in respiratory epithelial cells

1997 ◽  
Vol 272 (3) ◽  
pp. L504-L511 ◽  
Author(s):  
I. Jaspers ◽  
E. Flescher ◽  
L. C. Chen
Keyword(s):  
Transcription Factors ◽  
Dna Binding ◽  
Epithelial Cells ◽  
Inflammatory Cells ◽  
Binding Activity ◽  
Ozone Exposure ◽  
Air Exposure ◽  
Dna Binding Activity ◽  
Nf Kappab

Ozone, one of the most reactive oxidant gases to which humans are routinely exposed, induces inflammation in the lower airways. The airway epithelium is one of the first targets that inhaled ozone will encounter, but its role in airway inflammation is not well understood. Expression of inducible genes involved in the inflammatory response, such as interleukin (IL)-8, is controlled by transcription factors. Expression of the IL-8 gene is regulated by the transcription factors nuclear factor (NF)-kappaB, NF-IL-6, and possibly activator protein-1 (AP-1). Type II-like epithelial cells (A549) were grown on a collagen-coated membrane and exposed in vitro to 0.1 ppm ozone or air. Exposure to ozone induced DNA-binding activity of NF-kappaB, NF-IL-6, and AP-1. IL-8 mRNA and IL-8 protein levels were also increased after ozone exposure. These results link ozone-induced DNA-binding activity of transcription factors and the production of IL-8 by epithelial cells thus demonstrating a potential cellular cascade resulting in the recruitment of inflammatory cells into the airway lumen.

scholarly journals Regulation of Transcription Factors and Repression of Sp1 by Prolactin Signaling Through the Short Isoform of Its Cognate Receptor

Endocrinology ◽  
2009 ◽  
Vol 150 (7) ◽  
pp. 3327-3335 ◽  
Author(s):  
Y. Sangeeta Devi ◽  
Aurora Shehu ◽  
Carlos Stocco ◽  
Julia Halperin ◽  
Jamie Le ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Signaling Pathway ◽  
Short Form ◽  
Binding Activity ◽  
In Vivo Model ◽  
Regulation Of Transcription ◽  
Signaling Mechanism ◽  
Dna Binding Activity ◽  
And Function

Prolactin (PRL) affects the development and function of the reproductive system by binding to two types of receptors, which differ by the size of their intracellular domain in rodents. Whereas the signaling pathway through the long form of the receptor (PRL-RL) is well characterized, signaling through the short form (PRL-RS) remains obscure. In this investigation, we examined transcription factors regulated by PRL in the ovary and decidua of mice expressing only PRL-RS in a PRL receptor null background. These mice provide a powerful in vivo model to study the selective signaling mechanism of PRL through PRL-RS independent of PRL-RL. We also examined the regulation of transcription factors in ovarian and uterine cell lines stably transfected with PRL-RS or PRL-RL. We focused our investigation on transcription factors similarly regulated in both these tissues and clearly established that signaling through PRL-RS does not activate the JaK/Stat in vivo but leads to severe down-regulation of Sp1 expression, DNA binding activity, and nuclear localization, events that appear to involve the calmodulin-dependent protein kinase pathway. Our in vivo and in culture data demonstrate that the PRL-RS activates a signaling pathway distinct from that of the PRL-RL.

scholarly journals CD43-mediated Signals Induce DNA Binding Activity of AP-1, NF-AT, and NFκB Transcription Factors in Human T Lymphocytes

2000 ◽  
Vol 275 (40) ◽  
pp. 31460-31468 ◽  
Author(s):  
M. Angélica Santana ◽  
Gustavo Pedraza-Alva ◽  
Norma Olivares-Zavaleta ◽  
Vicente Madrid-Marina ◽  
Vaclav Horejsi ◽  
...  
Keyword(s):  
Transcription Factors ◽  
T Lymphocytes ◽  
Dna Binding ◽  
Binding Activity ◽  
Human T Lymphocytes ◽  
Dna Binding Activity

scholarly journals Expression of the genes encoding CCAAT-enhancer binding protein isoforms in the mouse mammary gland during lactation and involution

1998 ◽  
Vol 334 (1) ◽  
pp. 205-210 ◽  
Author(s):  
Georgios SABATAKOS ◽  
Gareth E. DAVIES ◽  
Maria GROSSE ◽  
Anthony CRYER ◽  
Dipak P. RAMJI
Keyword(s):  
Transcription Factors ◽  
Mammary Gland ◽  
Dna Binding ◽  
Binding Protein ◽  
Mouse Mammary Gland ◽  
Binding Activity ◽  
Protein Isoforms ◽  
Dna Binding Activity ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein

Transcription factors belonging to the CCAAT-enhancer binding protein (C/EBP) family have been implicated in the activation of gene expression in the mammary gland during lactation. We have therefore investigated the detailed expression profile of the C/EBP family during lactation and involution of the mouse mammary gland. The expression of C/EBPβ and C/EBPδ mRNA was low during lactation, increased dramatically at the beginning of involution and remained constant thereafter. In contrast, C/EBPα mRNA expression was relatively high during the early stages of lactation, declined to low levels during the late stages of lactation and at the start of involution, and increased again during involution. Electrophoretic mobility-shift assays showed a close correlation between the expression of the C/EBP genes and the functional C/EBP DNA-binding activity and, additionally, demonstrated the participation of heterodimers, formed from among the three proteins, in DNA–protein interactions. The DNA-binding activity of the activator protein 1 (AP1) family of transcription factors was also induced during involution. These results therefore point to potentially important regulatory roles for both the C/EBP and the AP1 family during lactation and involution of the mammary gland.

scholarly journals BosR Is A Novel Fur Family Member Responsive to Copper and Regulating Copper Homeostasis in Borrelia burgdorferi

2017 ◽  
Vol 199 (16) ◽  
Author(s):  
Peng Wang ◽  
Zhuoteng Yu ◽  
Thomas J. Santangelo ◽  
John Olesik ◽  
Yufeng Wang ◽  
...  
Keyword(s):  
Dna Binding ◽  
Borrelia Burgdorferi ◽  
Metal Ions ◽  
Metal Ion ◽  
Transition Metal Ions ◽  
Binding Activity ◽  
Ferric Uptake Regulator ◽  
Content Type ◽  
Dna Binding Activity ◽  
Cu Homeostasis

ABSTRACT The ferric uptake regulator (Fur) family of DNA-binding proteins represses and/or activates gene transcription via divalent metal ion-dependent signal sensing. The Borrelia burgdorferi Fur homologue, also known as Borrelia oxidative stress regulator (BosR), promotes spirochetal adaptation to the mammalian host by directly repressing the lipoproteins required for tick colonization and indirectly activating those required for establishing infection in the mammal. Here, we examined whether the DNA-binding activity of BosR was regulated by any of the four most prevalent transition metal ions in B. burgdorferi, Mn, Fe, Cu, and Zn. Our data indicated that in addition to a structural site occupied by Zn(II), BosR had two regulatory sites that could be occupied by Zn(II), Fe(II), or Cu(II) but not by Mn(II). While Fe(II) had no effect, Cu(II) and Zn(II) had a dose-dependent inhibitory effect on the BosR DNA-binding activity. Competition experiments indicated that Cu(II) had a higher affinity for BosR than Zn(II) or Fe(II). A BosR deficiency in B. burgdorferi resulted in a significant increase in the Cu level but no significant change in the levels of Mn, Fe, or Zn. These data suggest that Cu regulates BosR activity, and BosR in turn regulates Cu homeostasis in B. burgdorferi. While this regulatory paradigm is characteristic of the Fur family, BosR is the first one shown to be responsive to Cu(II), which may be an adaptation to the potentially high level of Cu present in the Lyme disease spirochete. IMPORTANCE Transition metal ions serve an essential role in the metabolism of all living organisms. Members of the ferric uptake regulator (Fur) family play critical roles in regulating the cellular homeostasis of transition metals in diverse bacteria, and their DNA-binding activity is often regulated by coordination of the cognate divalent metal ions. To date, regulators with metal ion specificity to Fe(II), Mn(II), Zn(II), and Ni(II) have all been described. In this study, we demonstrate that BosR, the sole Fur homologue in Borrelia burgdorferi, is responsive to Cu(II) and regulates Cu homeostasis in this bacterium, which may be an adaption to potentially Cu-rich milieu in the Lyme disease spirochete. This study has expanded the repertoire of the Fur family's metal ion specificity.

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