Structural modelling studies and immunoprophylactic potential ofBrugia malayiDEAD Box RNA helicase

Parasitology ◽  
2013 ◽  
Vol 140 (8) ◽  
pp. 1016-1025 ◽  
Author(s):  
MEGHNA SINGH ◽  
NIDHI SHRIVASTAVA ◽  
UZMA SAQIB ◽  
MOHAMMAD IMRAN SIDDIQI ◽  
SHAILJA MISRA-BHATTACHARYA
Keyword(s):  
Adverse Outcome ◽  
3D Structure ◽  
Rna Helicase ◽  
Mrna Splicing ◽  
Oxygen Species ◽  
Rna Helicases ◽  
Infective Larvae ◽  
Dead Box ◽  
Modelling Studies ◽  
Mastomys Coucha

SUMMARYDEAD Box RNA helicases are essential enzymes that are involved in RNA metabolic processes such as transcription, pre-mRNA splicing, translation initiation and RNA decay. We have previously over-expressed and biochemically characterized an immunodominant cDNA clone encoding DEAD box RNA helicase (BmL3-Helicase) isolated by immunoscreening of the larval stage cDNA library ofBrugia malayi.In the current study, the 3D structure was determined and the immunoprophylactic efficacy of BmL3-Helicase was investigated by immunizingMastomys couchawith the recombinant protein and subsequently challenging withB. malayiinfective larvae. The immunization had an adverse outcome on the establishment of challenged larvae resulting in a 67·4% reduction in adult parasite recovery, a 86·7% decrease in the microfilarial density and profound sterility of the recovered female worms. The immune response thus generated was investigated by measuring the levels of specific antibodies including IgG subclasses, reactive oxygen species and cytokines.

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

2017 ◽  
Vol 199 (13) ◽  
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.

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

1995 ◽  
Vol 308 (3) ◽  
pp. 839-846 ◽  
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.

scholarly journals Genera specific distribution of DEAD-box RNA helicases in cyanobacteria

2021 ◽  
Vol 7 (3) ◽  
Author(s):  
Denise S. Whitford ◽  
Brendan T. Whitman ◽  
George W. Owttrim
Keyword(s):  
Phylogenetic Analysis ◽  
Rna Helicase ◽  
Evolutionary Divergence ◽  
Sequence Motif ◽  
Rna Helicases ◽  
Homologous Proteins ◽  
Content Type ◽  
Conserved Sequence ◽  
Link Type ◽  
Dead Box

Although RNA helicases are essentially ubiquitous and perform roles in all stages of RNA metabolism, phylogenetic analysis of the DEAD (Asp-Glu-Ala-Asp)-box RNA helicase family in a single phylum has not been performed. Here, we performed a phylogenetic analysis on DEAD-box helicases from all currently available cyanobacterial genomes, comprising a total of 362 helicase protein sequences from 280 strains. DEAD-box helicases belonging to three distinct clades were observed. Two clades, the CsdA (cold shock DEAD-box A)-like and RhlE (RNA helicase E)-like helicases, cluster with the homologous proteins from Escherichia coli . The third clade, the CrhR (cyanobacterial RNA helicase Redox)-like helicases, is unique to cyanobacteria and characterized by a conserved sequence motif in the C-terminal extension. Restricted distribution is observed across cyanobacterial diversity with respect to both helicase type and strain. CrhR-like and CsdA-like helicases essentially never occur together, while RhlE always occurs with either a CrhR-like or CsdA-like helicase. CrhR-like and RhlE-like proteins occurred in filamentous cyanobacteria of the orders Nostocales , Oscillatoriales and Synechococcales . Similarly, CsdA- and RhlE-like proteins are restricted to unicellular cyanobacteria of the genera Cyanobium and Synechococcus . In addition, the unexpected occurrence of RhlE in two Synechococcus strains suggests recent acquisition and evolutionary divergence. This study, therefore, raises physiological and evolutionary questions as to why DEAD-box RNA helicases encoded in cyanobacterial lineages display restricted distributions, suggesting niches that require either CrhR or CsdA RNA helicase activity but not both. Extensive conservation of gene synteny surrounding the previously described rimO–crhR operon is also observed, indicating a role in the maintenance of photosynthesis. The analysis provides insights into the evolution, origin and dissemination of sequences within a single gene family to yield divergent functional roles.

scholarly journals The DEAD box RNA helicase Ddx39a is essential for myocyte and lens development in zebrafish

2017 ◽  
Author(s):  
Linlin Zhang ◽  
Beibei Li ◽  
Yuxi Yang ◽  
Ian C. Scott ◽  
Xin Lou
Keyword(s):  
Heart Development ◽  
Rna Helicase ◽  
Lens Fiber ◽  
Rna Helicases ◽  
Gene Encoding ◽  
Animal Development ◽  
Fiber Cells ◽  
Dead Box ◽  
The Dead ◽  
Almost All

AbstractRNA helicases from the DEAD-box family are found in almost all organisms and have important roles in RNA metabolism including RNA synthesis, processing and degradation. The function and mechanism of action of most of these helicases in animal development and human disease are largely unexplored. In a zebrafish mutagenesis screen to identify genes essential for heart development we identified a zebrafish mutant, which disrupts the gene encoding the RNA helicase DEAD-box 39a (ddx39a).Homozygous ddx39a mutant embryos exhibit profound cardiac and trunk muscle dystrophy, along with lens abnormalities caused by abrupt terminal differentiation of cardiomyocyte, myoblast and lens fiber cells. Further investigation indicated that loss of ddx39a hindered mRNA splicing of members of the kmt2 gene family, leading to mis-regulation of structural gene expression in cardiomyocyte, myoblast and lens fiber cells. Taken together, these results show that Ddx39a plays an essential role in establishment of proper epigenetic status during cell differentiation.

scholarly journals The temperature-regulated DEAD-box RNA helicase CrhR interactome: Autoregulation and photosynthesis-related transcripts

2021 ◽  
Author(s):  
Anzhela Migur ◽  
Florian Heyl ◽  
Janina Fuss ◽  
Afshan Srikumar ◽  
Bruno Huettel ◽  
...  
Keyword(s):  
Stress Responses ◽  
Rna Binding ◽  
Regulation Of Gene Expression ◽  
Physiological Role ◽  
Photosynthetic Electron Transport ◽  
Gene Families ◽  
Rna Helicase ◽  
Rna Helicases ◽  
Diverse Range ◽  
Dead Box

RNA helicases play crucial functions in RNA biology. In plants, RNA helicases are encoded by large gene families, performing roles in abiotic stress responses, development, the post-transcriptional regulation of gene expression as well as house-keeping functions. Several of these RNA helicases are targeted to the organelles, mitochondria and chloroplasts. Cyanobacteria are the direct evolutionary ancestors of plant chloroplasts. The cyanobacterium Synechocystis 6803 encodes a single DEAD-box RNA helicase, CrhR, that is induced by a range of abiotic stresses, including low temperature. Though the ΔcrhR mutant exhibits a severe cold-sensitive phenotype, the physiological function(s) performed by CrhR have not been described. To identify transcripts interacting with CrhR, we performed RNA co-immunoprecipitation with extracts from a Synechocystis crhR deletion mutant expressing the FLAG-tagged native CrhR or a K57A mutated version with an anticipated enhanced RNA binding. The composition of the interactome was strikingly biased towards photosynthesis-associated and redox-controlled transcripts. A transcript highly enriched in all experiments was the crhR mRNA, suggesting an auto-regulatory molecular mechanism. The identified interactome explains the described physiological role of CrhR in response to the redox poise of the photosynthetic electron transport chain and characterizes CrhR as an enzyme with a diverse range of transcripts as molecular targets.

Brr2p RNA helicase with a split personality: insights into structure and function

2010 ◽  
Vol 38 (4) ◽  
pp. 1105-1109 ◽  
Author(s):  
Daniela Hahn ◽  
Jean D. Beggs
Keyword(s):  
Domain Architecture ◽  
Rna Helicase ◽  
Structure And Function ◽  
Mrna Splicing ◽  
Eye Disease ◽  
Rna Helicases ◽  
Cellular Processes ◽  
Biochemical Studies ◽  
Split Personality ◽  
And Function

RNA helicases are involved in many cellular processes. Pre-mRNA splicing requires eight different DExD/H-box RNA helicases, which facilitate spliceosome assembly and remodelling of the intricate network of RNA rearrangements that are central to the splicing process. Brr2p, one of the spliceosomal RNA helicases, stands out through its unusual domain architecture. In the present review we highlight the advances made by recent structural and biochemical studies that have important implications for the mechanism and regulation of Brr2p activity. We also discuss the involvement of human Brr2 in retinitis pigmentosa, a degenerative eye disease, and how its functions in splicing might connect to the molecular pathology of the disease.

scholarly journals DEAD-Box RNA Helicase 42 Plays a Critical Role in Pre-mRNA Splicing under Cold Stress

2019 ◽  
Vol 182 (1) ◽  
pp. 255-271 ◽  
Author(s):  
Chung-An Lu ◽  
Chun-Kai Huang ◽  
Wen-Shan Huang ◽  
Tian-Sheng Huang ◽  
Hsin-Yi Liu ◽  
...  
Keyword(s):  
Cold Stress ◽  
Critical Role ◽  
Rna Helicase ◽  
Mrna Splicing ◽  
Dead Box

scholarly journals Structural and functional analysis of the RNA helicase Prp43 from the thermophilic eukaryoteChaetomium thermophilum

2016 ◽  
Vol 72 (2) ◽  
pp. 112-120 ◽  
Author(s):  
Marcel J. Tauchert ◽  
Jean-Baptiste Fourmann ◽  
Henning Christian ◽  
Reinhard Lührmann ◽  
Ralf Ficner
Keyword(s):  
Crystal Structure ◽  
Saccharomyces Cerevisiae ◽  
Functional Analysis ◽  
Rna Helicase ◽  
Mrna Splicing ◽  
Rna Helicases ◽  
Cellular Processes ◽  
Chaetomium Thermophilum ◽  
Rrna Maturation

RNA helicases are indispensable for all organisms in each domain of life and have implications in numerous cellular processes. The DEAH-box RNA helicase Prp43 is involved in pre-mRNA splicing as well as rRNA maturation. Here, the crystal structure ofChaetomium thermophilumPrp43 at 2.9 Å resolution is revealed. Furthermore, it is demonstrated that Prp43 fromC. thermophilumis capable of functionally replacing its orthologue fromSaccharomyces cerevisiaein spliceosomal disassembly assays.

scholarly journals Regulation of Alternative Splicing by the ATP-Dependent DEAD-Box RNA Helicase p72

2002 ◽  
Vol 22 (16) ◽  
pp. 5698-5707 ◽  
Author(s):  
Arnd Hönig ◽  
Didier Auboeuf ◽  
Marjorie M. Parker ◽  
Bert W. O'Malley ◽  
Susan M. Berget
Keyword(s):  
Alternative Splicing ◽  
Rna Splicing ◽  
Globin Gene ◽  
Rna Helicase ◽  
Close Relative ◽  
Rna Helicases ◽  
Enhancer Element ◽  
Dead Box ◽  
Precursor Rna

ABSTRACT Although a number of ATP-dependent RNA helicases are important for constitutive RNA splicing, no helicases have been implicated in alternative RNA splicing. Here, we show that the abundant DEAD-box RNA helicase p72, but not its close relative p68, affects the splicing of alternative exons containing AC-rich exon enhancer elements. The effect of p72 was tested by using mini-genes that undergo different types of alternative splicing. When the concentration of p72 was increased in transient transfections, the inclusion of enhancer-containing CD44 alternative exons v4 and v5 increased using a mini-gene that contained these exons and their flanking introns inserted into a β-globin gene. Other types of alternative splicing were not impacted by altering p72 concentrations. Mutation of the p72 helicase ATP-binding site or deletion of the carboxy-terminal region of the protein reduced the ability of the transfected protein to affect CD44 variable exon splicing. Use of in vitro extracts overexpressing p72 indicated that p72 becomes associated with complexes containing precursor RNA. Helicases have been implicated both in altering RNA-RNA interactions and in remodeling RNA-protein complexes. CD44 exon v4 contains a potential internal secondary structure element that base pairs the 5′ splice site with a region inside the exon located between enhancer elements. Mutations that destroyed this complementarity modestly increased inclusion in the absence of p72 but still responded to increasing p72 concentration like the wild-type exon, suggesting that p72 might have effects on protein-RNA interactions. In agreement with this hypothesis, p72 was not able to restore the inclusion of an exon mutated for its major enhancer element. Our results suggest that RNA helicases may be important alternative splicing regulatory factors.

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