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

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

Horticulturae ◽

10.3390/horticulturae4040040 ◽

2018 ◽

Vol 4 (4) ◽

pp. 40 ◽

Cited By ~ 1

Author(s):

Robert Price ◽

Cameron Parsons ◽

Sophia Kathariou

Keyword(s):

Listeria Monocytogenes ◽

Foodborne Pathogen ◽

Rna Helicase ◽

Relative Fitness ◽

Competitive Fitness ◽

Growth And Survival ◽

Dead Box ◽

Helicase Gene ◽

Genetic Features ◽

Flagellum Biosynthesis

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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Faculty Opinions recommendation of The DEAD-box RNA helicase Vad1 regulates multiple virulence-associated genes in Cryptococcus neoformans.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1024704.293704 ◽

2005 ◽

Author(s):

Herb Arst

Keyword(s):

Cryptococcus Neoformans ◽

Rna Helicase ◽

Dead Box ◽

The Dead

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Association of the Cold Shock DEAD-Box RNA Helicase RhlE to the RNA Degradosome in Caulobacter crescentus

Journal of Bacteriology ◽

10.1128/jb.00135-17 ◽

2017 ◽

Vol 199 (13) ◽

Cited By ~ 15

Author(s):

Angel A. Aguirre ◽

Alexandre M. Vicente ◽

Steven W. Hardwick ◽

Daniela M. Alvelos ◽

Ricardo R. Mazzon ◽

...

Keyword(s):

Low Temperature ◽

Caulobacter Crescentus ◽

Immunoblot Analysis ◽

Rna Helicase ◽

Rnase E ◽

Rna Helicases ◽

Content Type ◽

Dead Box ◽

Rna Degradosome ◽

The Dead

ABSTRACT In diverse bacterial lineages, multienzyme assemblies have evolved that are central elements of RNA metabolism and RNA-mediated regulation. The aquatic Gram-negative bacterium Caulobacter crescentus, which has been a model system for studying the bacterial cell cycle, has an RNA degradosome assembly that is formed by the endoribonuclease RNase E and includes the DEAD-box RNA helicase RhlB. Immunoprecipitations of extracts from cells expressing an epitope-tagged RNase E reveal that RhlE, another member of the DEAD-box helicase family, associates with the degradosome at temperatures below those optimum for growth. Phenotype analyses of rhlE, rhlB, and rhlE rhlB mutant strains show that RhlE is important for cell fitness at low temperature and its role may not be substituted by RhlB. Transcriptional and translational fusions of rhlE to the lacZ reporter gene and immunoblot analysis of an epitope-tagged RhlE indicate that its expression is induced upon temperature decrease, mainly through posttranscriptional regulation. RNase E pulldown assays show that other proteins, including the transcription termination factor Rho, a second DEAD-box RNA helicase, and ribosomal protein S1, also associate with the degradosome at low temperature. The results suggest that the RNA degradosome assembly can be remodeled with environmental change to alter its repertoire of helicases and other accessory proteins. IMPORTANCE DEAD-box RNA helicases are often present in the RNA degradosome complex, helping unwind secondary structures to facilitate degradation. Caulobacter crescentus is an interesting organism to investigate degradosome remodeling with change in temperature, because it thrives in freshwater bodies and withstands low temperature. In this study, we show that at low temperature, the cold-induced DEAD-box RNA helicase RhlE is recruited to the RNA degradosome, along with other helicases and the Rho protein. RhlE is essential for bacterial fitness at low temperature, and its function may not be complemented by RhlB, although RhlE is able to complement for rhlB loss. These results suggest that RhlE has a specific role in the degradosome at low temperature, potentially improving adaptation to this condition.

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The DEAD-box RNA helicase DDX5 acts as a positive regulator of Japanese encephalitis virus replication by binding to viral 3′ UTR

Antiviral Research ◽

10.1016/j.antiviral.2013.09.002 ◽

2013 ◽

Vol 100 (2) ◽

pp. 487-499 ◽

Cited By ~ 33

Author(s):

Chen Li ◽

Ling-ling Ge ◽

Peng-peng Li ◽

Yue Wang ◽

Ming-xia Sun ◽

...

Keyword(s):

Japanese Encephalitis Virus ◽

Virus Replication ◽

Japanese Encephalitis ◽

Rna Helicase ◽

Encephalitis Virus ◽

Positive Regulator ◽

Dead Box ◽

The Dead

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Crystal structure of yeast initiation factor 4A, a DEAD-box RNA helicase

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.97.24.13080 ◽

2000 ◽

Vol 97 (24) ◽

pp. 13080-13085 ◽

Cited By ~ 187

Author(s):

J. M. Caruthers ◽

E. R. Johnson ◽

D. B. McKay

Keyword(s):

Crystal Structure ◽

Rna Helicase ◽

Initiation Factor ◽

Dead Box

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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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