scholarly journals PHLPP1 counter-regulates STAT1-mediated inflammatory signaling

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Ksenya Cohen Katsenelson ◽  
Joshua D Stender ◽  
Agnieszka T Kawashima ◽  
Gema Lordén ◽  
Satoshi Uchiyama ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Target Genes ◽  
Cytokine Signaling ◽  
Ph Domain ◽  
Inflammatory Signaling ◽  
Gene Encoding ◽  
Lps Challenge ◽  
Escherichia Coli Infection ◽  
Localization Signal ◽  
Leucine Rich Repeat Protein

Inflammation is an essential aspect of innate immunity but also contributes to diverse human diseases. Although much is known about the kinases that control inflammatory signaling, less is known about the opposing phosphatases. Here we report that deletion of the gene encoding PH domain Leucine-rich repeat Protein Phosphatase 1 (PHLPP1) protects mice from lethal lipopolysaccharide (LPS) challenge and live Escherichia coli infection. Investigation of PHLPP1 function in macrophages reveals that it controls the magnitude and duration of inflammatory signaling by dephosphorylating the transcription factor STAT1 on Ser727 to inhibit its activity, reduce its promoter residency, and reduce the expression of target genes involved in innate immunity and cytokine signaling. This previously undescribed function of PHLPP1 depends on a bipartite nuclear localization signal in its unique N-terminal extension. Our data support a model in which nuclear PHLPP1 dephosphorylates STAT1 to control the magnitude and duration of inflammatory signaling in macrophages.

scholarly journals PHLPP1 Counter-regulates STAT1-mediated Inflammatory Signaling

2019 ◽  
Author(s):  
Ksenya Cohen-Katsenelson ◽  
Joshua D. Stender ◽  
Agnieszka T. Kawashima ◽  
Gema Lordén ◽  
Satoshi Uchiyama ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Target Genes ◽  
Cytokine Signaling ◽  
List Type ◽  
Ph Domain ◽  
Inflammatory Signaling ◽  
Lps Challenge ◽  
Localization Signal

ABSTRACTInflammation is an essential aspect of innate immunity but also contributes to diverse human diseases. Although much is known about the kinases that control inflammatory signaling, less is known about the opposing phosphatases. Here we report that deletion of the gene encoding PH domain Leucine-rich repeat Protein Phosphatase 1 (PHLPP1) protects mice from lethal lipopolysaccharide (LPS) challenge and liveEscherichia coliinfection. Investigation of PHLPP1 function in macrophages reveals that it controls the magnitude and duration of inflammatory signaling by dephosphorylating the transcription factor STAT1 on Ser727 to inhibit its activity, reduce its promoter residency, and reduce the expression of target genes involved in innate immunity and cytokine signaling. This previously undescribed function of PHLPP1 depends on a bipartite nuclear localization signal in its unique N-terminal extension. Our data support a model in which nuclear PHLPP1 dephosphorylates STAT1 to control the magnitude and duration of inflammatory signaling in macrophages.HIGHLIGHTSPHLPP1 controls the transcription of genes involved in inflammatory signalingPHLPP1 dephosphorylates STAT1 on Ser727 to reduce its transcriptional activityPHLPP1 has a nuclear localization signal and a nuclear exclusion signalLoss of PHLPP1 protects mice from sepsis-induced death

scholarly journals Transforming properties of chimeric TEL-JAK proteins in Ba/F3 cells

Blood ◽  
2000 ◽  
Vol 95 (6) ◽  
pp. 2076-2083 ◽  
Author(s):  
Virginie Lacronique ◽  
Anthony Boureux ◽  
Richard Monni ◽  
Stephanie Dumon ◽  
Martine Mauchauffé ◽  
...  
Keyword(s):  
Growth Factor ◽  
Tyrosine Kinase ◽  
Target Genes ◽  
Catalytic Domain ◽  
Dominant Negative ◽  
Janus Kinase ◽  
Cytokine Signaling ◽  
Mobility Shift ◽  
Gene Encoding ◽  
Oligomerization Domain

Abstract The involvement of the cytokine signaling pathway in oncogenesis has long been postulated. Recently, rearrangements of the gene encoding the tyrosine Janus kinase 2 (JAK2) have been reported in human leukemias indicating a direct JAK-signal transduction and activator of transcription (STAT)-mediated leukemic process. The leukemia-associated TEL-JAK2 fusion protein is formed by the oligomerization domain of the translocated ets leukemia (TEL) protein fused to the catalytic domain of JAK2. TEL-mediated oligomerization results in a constitutive tyrosine kinase activity that, in turn, is able to confer growth factor independence to the murine hematopoietic interleukin-3 (IL-3)-dependent Ba/F3 cell line. Results of the present study indicate that fusion proteins containing the oligomerization domain of TEL and the tyrosine kinase domains of Jak1, Jak2, JAK3, or TYK2 share similar properties and are able to efficiently substitute for the survival and mitogenic signals controlled by IL-3, without concomitant activation of the IL-3 receptor. Electrophoretic mobility shift assays demonstrated Stat5 as the only activated Stat factor in TEL-Jak2- and TEL-Jak1-expressing cells, whereas other Stats, namely Stat1 and Stat3, could be detected in TEL-JAK3-, TEL-TYK2-, and also in TEL-ABL-expressing Ba/F3 cells. High levels of expression of the Stat5-target genes pim-1, osm, and Cis were observed in all the cytokine-independent cell lines. Furthermore, the expression of a dominant negative form of Stat5A markedly interfered with the growth factor independence process mediated by TEL-Jak2 in Ba/F3 cells. Because the BCR-ABL and TEL-PDGFβR oncoproteins also activate Stat5, activation of this factor should be a crucial step in activated tyrosine kinase-mediated leukemogenesis.

scholarly journals Differential activation mechanisms of two isoforms of Gcr1 transcription factor generated from spliced and un-spliced transcripts in Saccharomyces cerevisiae

2020 ◽  
Author(s):  
Seungwoo Cha ◽  
Chang Pyo Hong ◽  
Hyun Ah Kang ◽  
Ji-Sook Hahn
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcription Factor ◽  
Target Genes ◽  
Gene Encoding ◽  
Metabolic Switch ◽  
Differential Activation ◽  
N Terminus ◽  
Activation Mechanisms ◽  
In Trans ◽  
Separate Activation

Abstract Gcr1, an important transcription factor for glycolytic genes in Saccharomyces cerevisiae, was recently revealed to have two isoforms, Gcr1U and Gcr1S, produced from un-spliced and spliced transcripts, respectively. In this study, by generating strains expressing only Gcr1U or Gcr1S using the CRISPR/Cas9 system, we elucidate differential activation mechanisms of these two isoforms. The Gcr1U monomer forms an active complex with its coactivator Gcr2 homodimer, whereas Gcr1S acts as a homodimer without Gcr2. The USS domain, 55 residues at the N-terminus existing only in Gcr1U, inhibits dimerization of Gcr1U and even acts in trans to inhibit Gcr1S dimerization. The Gcr1S monomer inhibits the metabolic switch from fermentation to respiration by directly binding to the ALD4 promoter, which can be restored by overexpression of the ALD4 gene, encoding a mitochondrial aldehyde dehydrogenase required for ethanol utilization. Gcr1U and Gcr1S regulate almost the same target genes, but show unique activities depending on growth phase, suggesting that these isoforms play differential roles through separate activation mechanisms depending on environmental conditions.

Autoregulated Expression of Schizosaccharomyces pombe Meiosis-Specific Transcription Factor Mei4 and a Genome-Wide Search for Its Target Genes

Genetics ◽  
2000 ◽  
Vol 154 (4) ◽  
pp. 1497-1508 ◽  
Author(s):  
Hiroko Abe ◽  
Chikashi Shimoda
Keyword(s):  
Transcription Factor ◽  
Schizosaccharomyces Pombe ◽  
Target Genes ◽  
Northern Blotting ◽  
Forkhead Transcription Factor ◽  
Gene Encoding ◽  
Putative Promoter Region ◽  
Cis Acting ◽  
A Genome ◽  
Genome Wide Search

Abstract The Schizosaccharomyces pombe mei4+ gene encoding a forkhead transcription factor is necessary for the progression of meiosis and sporulation. We searched for novel meiotic genes, the expression of which is dependent on Mei4p, since only the spo6+ gene has been assigned to its targets. Six known genes responsible for meiotic recombination were examined by Northern blotting, but none were Mei4 dependent for transcription. We determined the important cis-acting element, designated FLEX, to which Mei4p can bind. The S. pombe genome sequence database (The Sanger Centre, UK) was scanned for the central core heptamer and its flanking 3′ sequence of FLEX composed of 17 nucleotides, and 10 candidate targets of Mei4 were selected. These contained a FLEX-like sequence in the 5′ upstream nontranslatable region within 1 kb of the initiation codon. Northern blotting confirmed that 9 of them, named mde1+ to mde9+, were transcriptionally induced during meiosis and were dependent on mei4+. Most mde genes have not been genetically defined yet, except for mde9+, which is identical to spn5+, which encodes one of the septin family of proteins. mde3+ and a related gene pit1+ encode proteins related to Saccharomyces cerevisiae Ime2. The double disruptant frequently produced asci having an abnormal number and size of spores, although it completed meiosis. We also found that the forkhead DNA-binding domain of Mei4p binds to the FLEX-like element in the putative promoter region of mei4 and that the maximum induction level of mei4 mRNA required functional mei4 activity. Furthermore, expression of a reporter gene driven by the authentic mei4 promoter was induced in vegetative cells by ectopic overproduction of Mei4p. These results suggest that mei4 transcription is positively autoregulated.

scholarly journals SfnR2 Regulates Dimethyl Sulfide-Related Utilization inPseudomonas aeruginosaPAO1

2018 ◽  
Vol 201 (4) ◽  
Author(s):  
Benjamin R. Lundgren ◽  
Zaara Sarwar ◽  
Kyle S. Feldman ◽  
Joseph M. Shoytush ◽  
Christopher T. Nomura
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Target Genes ◽  
Dimethyl Sulfide ◽  
Sulfur Compound ◽  
Main Function ◽  
Gene Encoding ◽  
Content Type ◽  
First Results ◽  
Terrestrial Environments ◽  
Initial Activation

ABSTRACTDimethyl sulfide (DMS) is a volatile sulfur compound produced mainly from the degradation of dimethylsulfoniopropionate (DMSP) in marine environments. DMS undergoes oxidation to form dimethyl sulfoxide (DMSO), dimethyl sulfone (DMSO2), and methanesulfonate (MSA), all of which occur in terrestrial environments and are accessible for consumption by various microorganisms. The purpose of the present study was to determine how the enhancer-binding proteins SfnR1 and SfnR2 contribute to the utilization of DMS and its derivatives inPseudomonas aeruginosaPAO1. First, results from cell growth experiments showed that deletion of eithersfnR2orsfnG, a gene encoding a DMSO2-monooxygenase, significantly inhibits the ability ofP. aeruginosaPAO1 to use DMSP, DMS, DMSO, and DMSO2as sulfur sources. Deletion of thesfnR1ormsuEDCgenes, which encode a MSA desulfurization pathway, did not abolish the growth ofP. aeruginosaPAO1 on any sulfur compound tested. Second, data collected from β-galactosidase assays revealed that themsuEDC-sfnR1operon and thesfnGgene are induced in response to sulfur limitation or nonpreferred sulfur sources, such as DMSP, DMS, and DMSO, etc. Importantly, SfnR2 (and not SfnR1) is essential for this induction. Expression ofsfnR2is induced under sulfur limitation but independently of SfnR1 or SfnR2. Finally, the results of this study suggest that the main function of SfnR2 is to direct the initial activation of themsuEDC-sfnR1operon in response to sulfur limitation or nonpreferred sulfur sources. Once expressed, SfnR1 contributes to the expression ofmsuEDC-sfnR1,sfnG, and other target genes involved in DMS-related metabolism inP. aeruginosaPAO1.IMPORTANCEDimethyl sulfide (DMS) is an important environmental source of sulfur, carbon, and/or energy for microorganisms. For various bacteria, includingPseudomonas,Xanthomonas, andAzotobacter, DMS utilization is thought to be controlled by the transcriptional regulator SfnR. Adding more complexity, some bacteria, such asAcinetobacter baumannii,Enterobacter cloacae, andPseudomonas aeruginosa, possess two, nonidentical SfnR proteins. In this study, we demonstrate that SfnR2 and not SfnR1 is the principal regulator of DMS metabolism inP. aeruginosaPAO1. Results suggest that SfnR1 has a supportive but nonessential role in the positive regulation of genes required for DMS utilization. This study not only enhances our understanding of SfnR regulation but, importantly, also provides a framework for addressing gene regulation through dual SfnR proteins in other bacteria.

scholarly journals Zebrafish nephrosin helps host defence against Escherichia coli infection

Open Biology ◽  
2017 ◽  
Vol 7 (8) ◽  
pp. 170040 ◽  
Author(s):  
Qianqian Di ◽  
Qing Lin ◽  
Zhibin Huang ◽  
Yali Chi ◽  
Xiaohui Chen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Innate Immunity ◽  
Host Defence ◽  
Bacterial Burden ◽  
Wild Type ◽  
Lower Survival Rate ◽  
E Coli ◽  
Escherichia Coli Infection ◽  
Effective Models

Neutrophils play important roles in innate immunity and are mainly dependent on various enzyme-containing granules to kill engulfed microorganisms. Zebrafish nephrosin ( npsn ) is specifically expressed in neutrophils; however, its function is largely unknown. Here, we generated an npsn mutant ( npsn smu5 ) via CRISPR/Cas9 to investigate the in vivo function of Npsn. The overall development and number of neutrophils remained unchanged in npsn -deficient mutants, whereas neutrophil antibacterial function was defective. Upon infection with Escherichia coli , the npsn smu5 mutants exhibited a lower survival rate and more severe bacterial burden, as well as augmented inflammatory response to challenge with infection when compared with wild-type embryos, whereas npsn -overexpressing zebrafish exhibited enhanced host defence against E. coli infection. These findings demonstrated that zebrafish Npsn promotes host defence against bacterial infection. Furthermore, our findings suggested that npsn -deficient and -overexpressing zebrafish might serve as effective models of in vivo innate immunity.

scholarly journals A conserved long noncoding RNA, GAPLINC, modulates the immune response during endotoxic shock

2021 ◽  
Vol 118 (7) ◽  
pp. e2016648118
Author(s):  
Apple Cortez Vollmers ◽  
Sergio Covarrubias ◽  
Daisy Kuang ◽  
Aaron Shulkin ◽  
Justin Iwuagwu ◽  
...  
Keyword(s):  
Immune Response ◽  
Knockout Mice ◽  
Noncoding Rna ◽  
Target Genes ◽  
Blood Clot ◽  
Multiorgan Failure ◽  
Endotoxic Shock ◽  
Negative Regulator ◽  
Inflammatory Genes ◽  
Lps Challenge

Recent studies have identified thousands of long noncoding RNAs (lncRNAs) in mammalian genomes that regulate gene expression in different biological processes. Although lncRNAs have been identified in a variety of immune cells and implicated in immune response, the biological function and mechanism of the majority remain unexplored, especially in sepsis. Here, we identify a role for a lncRNA—gastric adenocarcinoma predictive long intergenic noncoding RNA (GAPLINC)—previously characterized for its role in cancer, now in the context of innate immunity, macrophages, and LPS-induced endotoxic shock. Transcriptome analysis of macrophages from humans and mice reveals that GAPLINC is a conserved lncRNA that is highly expressed following macrophage differentiation. Upon inflammatory activation, GAPLINC is rapidly down-regulated. Macrophages depleted of GAPLINC display enhanced expression of inflammatory genes at baseline, while overexpression of GAPLINC suppresses this response. Consistent with GAPLINC-depleted cells, Gaplinc knockout mice display enhanced basal levels of inflammatory genes and show resistance to LPS-induced endotoxic shock. Mechanistically, survival is linked to increased levels of nuclear NF-κB in Gaplinc knockout mice that drives basal expression of target genes typically only activated following inflammatory stimulation. We show that this activation of immune response genes prior to LPS challenge leads to decreased blood clot formation, which protects Gaplinc knockout mice from multiorgan failure and death. Together, our results identify a previously unknown function for GAPLINC as a negative regulator of inflammation and uncover a key role for this lncRNA in modulating endotoxic shock.

scholarly journals Mechanism of innate immune reprogramming by a fungal meningitis pathogen

2021 ◽  
Author(s):  
Eric V. Dang ◽  
Susan Lei ◽  
Atanas Radkov ◽  
Hiten Madhani
Keyword(s):  
Innate Immunity ◽  
Fungal Pathogens ◽  
Forward Genetics ◽  
Alternative Activation ◽  
Cytokine Signaling ◽  
Alternatively Activated Macrophages ◽  
Fungal Meningitis

How deadly fungal pathogens overcome mammalian innate immunity is largely unknown. Cryptococcus neoformans, the most common cause of fungal meningitis, induces a pathogenic type 2 response characterized by pulmonary eosinophilia and alternatively activated macrophages. Using forward genetics, we identified a fungal secreted protein, Cpl1, necessary and sufficient to enhance alternative activation of primary macrophages in vitro. Cpl1-enhanced polarization requires Toll-like receptor 4, a known mediator of allergen-induced type 2 responses. Cpl1 is essential for virulence, drives polarization of interstitial macrophages in vivo, and requires type 2 cytokine signaling for its impact on infectivity. C. neoformans selectively associates with polarized interstitial macrophages during infection, supporting a direct host-pathogen interaction. This work identifies a secreted effector produced by a human fungal pathogen that reprograms innate immunity to enable tissue infection.

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