RNA Helicase Mediates Competitive Fitness of Listeria monocytogenes on the Surface of Cantaloupe

Listeria monocytogenes is a foodborne pathogen that is implicated in numerous outbreaks of disease (listeriosis) via fresh produce. The genetic features of L. monocytogenes that allow adherence and growth on produce remain largely uncharacterized. In this study, two non-motile transposon mutants were characterized for attachment, growth, and survival on the surface of cantaloupe rind. One of the mutants, L1E4, harbored a single transposon insertion in a DEAD-box RNA helicase gene (lmo0866 homolog), while the other, M1A5, harbored an insertion in a gene from a flagellum biosynthesis and chemotaxis gene cluster (lmo0694 homolog). When inoculated alone, neither mutant was significantly impaired in growth or survival on the surface of cantaloupe at either 25 or 37 °C. However, when co-inoculated with the wildtype parental strain, the RNA helicase mutant L1E4 had a clear competitive disadvantage, while the relative fitness of M1A5 was not noticeably impacted. Genetic complementation of L1E4 with the intact RNA helicase gene restored relative fitness on cantaloupe. The findings suggest that the DEAD-box RNA helicase encoded by the lmo0866 homolog is critical for relative fitness of L. monocytogenes on cantaloupe. Mutant L1E4 was pleiotropic, being not only non-motile but also cold-sensitive and with reduced hemolytic activity, warranting further studies to elucidate the role of this helicase in the competitive fitness of L. monocytogenes on produce.

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The embryonic RNA helicase gene (ERH): a new member of the DEAD box family of RNA helicases

Biochemical Journal ◽

10.1042/bj3080839 ◽

1995 ◽

Vol 308 (3) ◽

pp. 839-846 ◽

Cited By ~ 15

Author(s):

J Sowden ◽

W Putt ◽

K Morrison ◽

R Beddington ◽

Y Edwards

Keyword(s):

Expression Profile ◽

Sequence Similarity ◽

Rna Helicase ◽

Chromosome 1 ◽

Rna Helicases ◽

High Sequence Similarity ◽

Dead Box ◽

Isolation And Characterization ◽

Helicase Gene ◽

The Dead

DEAD box proteins share several highly conserved motifs including the characteristic Asp-Glu-Ala-Asp (D-E-A-D in the amino acid single-letter code) motif and have established or putative ATP-dependent RNA helicase activity. These proteins are implicated in a range of cellular processes that involve regulation of RNA function, including translation initiation, RNA splicing and ribosome assembly. Here we describe the isolation and characterization of an embryonic RNA helicase gene, ERH, which maps to mouse chromosome 1 and encodes a new member of the DEAD box family of proteins. The predicted ERH protein shows high sequence similarity to the testes-specific mouse PL10 and to the maternally acting Xenopus An3 helicase proteins. The ERH expression profile is similar, to that of An3, which localizes to the animal hemisphere of oocytes and is abundantly expressed in the embryo. ERH is expressed in oocytes and is a ubiquitous mRNA in the 9 days-post-conception embryo, and at later stages of development shows a more restricted pattern of expression in brain and kidney. The similarities in sequence and in expression profile suggest that ERH is the murine equivalent of the Xenopus An3 gene, and we propose that ERH plays a role in translational activation of mRNA in the oocyte and early embryo.

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The RNA helicase DDX5 promotes alveolar rhabdomyosarcoma growth and survival

10.1101/2020.07.08.194092 ◽

2020 ◽

Author(s):

Alberto Gualtieri ◽

Valerio Licursi ◽

Chiara Mozzetta

Keyword(s):

Gene Expression ◽

Soft Tissue ◽

Soft Tissue Sarcoma ◽

Therapeutic Target ◽

Rna Helicase ◽

Potential Therapeutic Target ◽

Growth And Survival ◽

Dead Box ◽

Pharmacological Targets ◽

Xenograft Models

AbstractRhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma of childhood characterized by the inability to exit the proliferative myoblast-like stage. The alveolar fusion positive subtype (FP-ARMS) is the most aggressive and is mainly caused by the expression of PAX3/7-FOXO1 oncoproteins, which are challenging pharmacological targets. Thus, other therapeutic vulnerabilities resulting from gene expression changes are progressively being recognized. Here, we identified the DEAD box RNA helicase 5 (DDX5) as a potential therapeutic target to inhibit FP-ARMS growth. We show that DDX5 is overexpressed in alveolar RMS cells, demonstrating that its depletion drastically decreases FP-ARMS viability and slows tumor growth in xenograft models. Mechanistically, we provide evidence that DDX5 functions upstream the G9a/AKT survival signalling pathway, by modulating G9a protein stability. Finally, we show that G9a interacts with PAX3-FOXO1 and regulates its activity, thus sustaining FP-ARMS myoblastic state. Together, our findings identify a novel survival-promoting loop in FP-ARMS and highlight DDX5 as potential therapeutic target to arrest rhabdomyosarcoma growth.

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Investigation of a Novel Salt Stress-Responsive Pathway Mediated by Arabidopsis DEAD-Box RNA Helicase Gene AtRH17 Using RNA-Seq Analysis

International Journal of Molecular Sciences ◽

10.3390/ijms21051595 ◽

2020 ◽

Vol 21 (5) ◽

pp. 1595 ◽

Cited By ~ 1

Author(s):

Hye-Yeon Seok ◽

Linh Vu Nguyen ◽

Doai Van Nguyen ◽

Sun-Young Lee ◽

Yong-Hwan Moon

Keyword(s):

Salt Stress ◽

Stress Tolerance ◽

Stress Responses ◽

Rna Helicase ◽

Rna Seq ◽

Salt Stress Tolerance ◽

Salt Stress Condition ◽

Dead Box ◽

Helicase Gene ◽

Upregulated Genes

Previously, we reported that overexpression of AtRH17, an Arabidopsis DEAD-box RNA helicase gene, confers salt stress-tolerance via a pathway other than the well-known salt stress-responsive pathways. To decipher the salt stress-responsive pathway in AtRH17-overexpressing transgenic plants (OXs), we performed RNA-Sequencing and identified 397 differentially expressed genes between wild type (WT) and AtRH17 OXs. Among them, 286 genes were upregulated and 111 genes were downregulated in AtRH17 OXs relative to WT. Gene ontology annotation enrichment and KEGG pathway analysis showed that the 397 upregulated and downregulated genes are involved in various biological functions including secretion, signaling, detoxification, metabolic pathways, catabolic pathways, and biosynthesis of secondary metabolites as well as in stress responses. Genevestigator analysis of the upregulated genes showed that nine genes, namely, LEA4-5, GSTF6, DIN2/BGLU30, TSPO, GSTF7, LEA18, HAI1, ABR, and LTI30, were upregulated in Arabidopsis under salt, osmotic, and drought stress conditions. In particular, the expression levels of LEA4-5, TSPO, and ABR were higher in AtRH17 OXs than in WT under salt stress condition. Taken together, our results suggest that a high AtRH17 expression confers salt stress-tolerance through a novel salt stress-responsive pathway involving nine genes, other than the well-known ABA-dependent and ABA-independent pathways.

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SY-20 The TBK-1 substrate DDX3X, a DEAD-box RNA helicase, provides innate immunity to listeria monocytogenes

Cytokine ◽

10.1016/j.cyto.2008.07.337 ◽

2008 ◽

Vol 43 (3) ◽

pp. 304 ◽

Cited By ~ 1

Author(s):

Thomas Decker ◽

Didier Soulat ◽

Tilmann Bürckstümmer ◽

Sandra Westermayer ◽

Adriana Goncalves ◽

...

Keyword(s):

Innate Immunity ◽

Listeria Monocytogenes ◽

Rna Helicase ◽

Dead Box

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Inactivation of a Cold-Induced Putative RNA Helicase Gene of Listeria monocytogenes Is Accompanied by Failure To Grow at Low Temperatures but Does Not Affect Freeze-Thaw Tolerance

Journal of Food Protection ◽

10.4315/0362-028x-73.8.1474 ◽

2010 ◽

Vol 73 (8) ◽

pp. 1474-1479 ◽

Cited By ~ 12

Author(s):

REHA O. AZIZOGLU ◽

S. KATHARIOU

Keyword(s):

Listeria Monocytogenes ◽

Normal Growth ◽

Rna Helicase ◽

Soft Agar ◽

Freezing And Thawing ◽

Freeze Thaw ◽

Transposon Insertion ◽

Helicase Gene ◽

Repeated Freezing ◽

Cold Sensitive

Freeze-thaw tolerance (cryotolerance) of Listeria monocytogenes is markedly influenced by temperature of growth of the bacteria, and may involve responses to low-temperature stresses encountered during freezing and thawing. A cold-sensitive mariner-based transposon mutant of L. monocytogenes F2365 was found to harbor a single insertion in LMOf2365_1746, encoding a putative RNA helicase, and earlier shown by other investigators to be induced during 4°C growth of L. monocytogenes. The mutant had normal growth at 37°C but completely failed to grow at either 4 or 10°C, and had impaired growth and reduced swarming on soft agar at 25°C. However, the mutation had no discernible influence on the ability of the bacteria to tolerate repeated freezing and thawing after growth at either 25 or 37°C. The findings suggest that the transposon insertion in the putative helicase gene, in spite of the severely cold-sensitive phenotype that accompanies it, does not affect the ability of the bacteria to cope with cold-related stresses encountered during repeated freezing and thawing.

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An evolutionarily conserved, alternatively spliced, intron in the p68/DDX5 DEAD-box RNA helicase gene encodes a novel miRNA

RNA ◽

10.1261/rna.2591611 ◽

2011 ◽

Vol 17 (4) ◽

pp. 555-562 ◽

Cited By ~ 12

Author(s):

H. C. Moore ◽

M. Johnston ◽

S. M. Nicol ◽

J.-C. Bourdon ◽

A. M. Thompson ◽

...

Keyword(s):

Rna Helicase ◽

Novel Mirna ◽

Dead Box ◽

Helicase Gene ◽

Evolutionarily Conserved ◽

Alternatively Spliced

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Growth and Survival of Attached Listeria on Lettuce and Stainless Steel Varies by Strain and Surface Type

Journal of Food Protection ◽

10.4315/jfp-20-434 ◽

2021 ◽

Author(s):

Lisa Gorski ◽

Samarpita Walker ◽

Kelly F Romanolo ◽

Sophia Kathariou

Keyword(s):

Stainless Steel ◽

Listeria Monocytogenes ◽

Fluorescent Protein ◽

Foodborne Pathogen ◽

Surface Growth ◽

Growth And Survival ◽

Abiotic Surfaces ◽

Serotype 1 ◽

Serotype 4B ◽

Green Fluorescent

The foodborne pathogen Listeria monocytogenes lives as a saprophyte in nature and can adhere to and grows on surfaces as diverse as leaves, sediment, and stainless steel. To discern the mechanisms used by L. monocytogenes for attachment and growth on various surfaces, we studied interactions between the pathogen on lettuce and stainless steel. A panel of 24 strains (23 of Listeria monocytogenes and 1 L. innocua ) was screened for attachment and growth on lettuce at 4 o C and 25 o C and on stainless steel at 10 o C and 37 o C. Overnight growth of attached cells resulted in a 0 – 3 log increase on lettuce, depending on the strain and the temperature. Among the worst performing strains on lettuce were two from a large cantaloupe outbreak, indicating that factors important for interactions with cantaloupe may be different from those required on lettuce tissue. Strains that grew the best on lettuce belonged to serotypes 1/2a, 1/2b, and 4b and were from cheese, potatoes, and water/sediment near produce fields. Confocal microscopy of L. monocytogenes tagged with constitutively expressed green fluorescent protein indicated associations with the cut edges and veins of lettuce leaves. On stainless steel coupons, there was a 5 – 7 log increase at 10 o C after 7 d and a 4 – 7 log increase at 37 o C after 40 h. Statistically, surface growth on stainless steel was better for serotype 1/2a than for serotype 4b strains, even though certain serotype 4b strains grew well on the coupons. The latter included strains that originated from produce and water/sediment. Some strains were fit in both environments, while others showed variability between the two different surfaces. Further analysis of these strains should reveal molecular factors needed for adherence and surface growth of L. monocytogenes on different biotic and abiotic surfaces.

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Roles of Four Putative DEAD-Box RNA Helicase Genes in Growth of Listeria monocytogenes EGD-e under Heat, pH, Osmotic, Ethanol, and Oxidative Stress Conditions

Applied and Environmental Microbiology ◽

10.1128/aem.01526-12 ◽

2012 ◽

Vol 78 (19) ◽

pp. 6875-6882 ◽

Cited By ~ 14

Author(s):

Annukka Markkula ◽

Miia Lindström ◽

Per Johansson ◽

Johanna Björkroth ◽

Hannu Korkeala

Keyword(s):

Oxidative Stress ◽

Listeria Monocytogenes ◽

Stress Tolerance ◽

Deletion Mutant ◽

Rna Helicase ◽

Wild Type ◽

Content Type ◽

Oxidative Stresses ◽

Dead Box ◽

Mutant Strains

ABSTRACTTo examine the role of the four putative DEAD-box RNA helicase genes ofListeria monocytogenesEGD-e in stress tolerance, the growth of the Δlmo0866, Δlmo1246, Δlmo1450, and Δlmo1722deletion mutant strains at 42.5°C, at pH 5.6 or pH 9.4, in 6% NaCl, in 3.5% ethanol, and in 5 mM H2O2was studied. Restricted growth of the Δlmo0866deletion mutant strain in 3.5% ethanol suggests that Lmo0866 contributes to ethanol stress tolerance ofL. monocytogenesEGD-e. The Δlmo1450mutant strain showed negligible growth at 42.5°C, at pH 9.4, and in 5 mM H2O2and a lower maximum growth temperature than the wild-type EGD-e, suggesting that Lmo1450 is involved in the tolerance ofL. monocytogenesEGD-e to heat, alkali, and oxidative stresses. The altered stress tolerance of the Δlmo0866and Δlmo1450deletion mutant strains did not correlate with changes in relative expression levels oflmo0866andlmo1450genes under corresponding stresses, suggesting that Lmo0866- and Lmo1450-dependent tolerance to heat, alkali, ethanol, or oxidative stress is not regulated at the transcriptional level. Growth of the Δlmo1246and Δlmo1722deletion mutant strains did not differ from that of the wild-type EGD-e under any of the conditions tested, suggesting that Lmo1246 and Lmo1722 have no roles in the growth ofL. monocytogenesEGD-e under heat, pH, osmotic, ethanol, or oxidative stress. This study shows that the putative DEAD-box RNA helicase geneslmo0866andlmo1450play important roles in tolerance ofL. monocytogenesEGD-e to ethanol, heat, alkali, and oxidative stresses.

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p68 RNA helicase: identification of a nucleolar form and cloning of related genes containing a conserved intron in yeasts.

Molecular and Cellular Biology ◽

10.1128/mcb.11.3.1326 ◽

1991 ◽

Vol 11 (3) ◽

pp. 1326-1333 ◽

Cited By ~ 87

Author(s):

R D Iggo ◽

D J Jamieson ◽

S A MacNeill ◽

J Southgate ◽

J McPheat ◽

...

Keyword(s):

Simian Virus 40 ◽

Rna Helicase ◽

Simian Virus ◽

T Antigen ◽

Functional Roles ◽

Dead Box ◽

Helicase Gene ◽

P68 Rna Helicase ◽

Living Organisms ◽

Yeast Genes

The human p68 protein is an RNA-dependent ATPase and RNA helicase which was first identified because of its immunological cross-reaction with a viral RNA helicase, simian virus 40 large T antigen. It belongs to a recently discovered family of proteins (DEAD box proteins) that share extensive regions of amino acid sequence homology, are ubiquitous in living organisms, and are involved in many aspects of RNA metabolism, including splicing, translation, and ribosome assembly. We have shown by immunofluorescent microscopy that mammalian p68, which is excluded from the nucleoli during interphase, translocates to prenucleolar bodies during telophase. We have cloned 55% identical genes from both Schizosaccharomyces pombe and Saccharomyces cerevisiae and shown that they are essential in both yeasts. The human and yeast genes contain a large intron whose position has been precisely conserved. In S. cerevisiae, the intron is unusual both because of its size and because of its location near the 3' end of the gene. We discuss possible functional roles for such an unusual intron in an RNA helicase gene.

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