scholarly journals Contribution of DEAH-box protein DHX16 in human pre-mRNA splicing

2010 ◽  
Vol 429 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Marieta Gencheva ◽  
Mitsuo Kato ◽  
Alain N.S. Newo ◽  
Ren-Jang Lin

Studies of mammalian splicing factors are often focused on small nuclear ribonucleoproteins or regulatory RNA-binding proteins, such as hnRNP (heterogeneous nuclear ribonucleoprotein) and SR proteins (serine/arginine-rich proteins); however, much less is known about the contribution of DExD/H-box proteins or RNA helicases in mammalian pre-mRNA splicing. The human DEAH-box protein DHX16 [also known as DBP2 (DEAD-box protein 2)], is homologous with Caenorhabditis elegans Mog-4, Schizosaccharomyces pombe Prp8 and Saccharomyces cerevisiae Prp2. In the present study, we show that DHX16 is required for pre-mRNA splicing after the formation of a pre-catalytic spliceosome. We found that anti-DHX16 antiserum inhibited the splicing reaction in vitro and the antibody immunoprecipitated pre-mRNA, splicing intermediates and spliceosomal small nuclear RNAs. Cells that expressed DHX16 that had a mutation in the helicase domain accumulated unspliced intron-containing minigene transcripts. Nuclear extracts isolated from the dominant-negative DHX16-G724N-expressing cells formed splicing complex B, but were impaired in splicing. Adding extracts containing DHX16-G724N or DHX16-S552L mutant proteins to HeLa cell nuclear extracts resulted in reduced splicing, indicating that the mutant protein directly inhibited splicing in vitro. Therefore our results show that DHX16 is needed for human pre-mRNA splicing at a step analogous to that mediated by the S. cerevisiae spliceosomal ATPase Prp2.

1997 ◽  
Vol 17 (11) ◽  
pp. 6402-6409 ◽  
Author(s):  
L Wu ◽  
P J Good ◽  
J D Richter

The translational activation of several maternal mRNAs in Xenopus laevis is dependent on cytoplasmic poly(A) elongation. Messages harboring the UUUUUAU-type cytoplasmic polyadenylation element (CPE) in their 3' untranslated regions (UTRs) undergo polyadenylation and translation during oocyte maturation. This CPE is bound by the protein CPEB, which is essential for polyadenylation. mRNAs that have the poly(U)12-27 embryonic-type CPE (eCPE) in their 3' UTRs undergo polyadenylation and translation during the early cleavage and blastula stages. A 36-kDa eCPE-binding protein in oocytes and embryos has been identified by UV cross-linking. We now report that this 36-kDa protein is ElrA, a member of the ELAV family of RNA-binding proteins. The proteins are identical in size, antibody directed against ElrA immunoprecipitates the 36-kDa protein, and the two proteins have the same RNA binding specificity in vitro. C12 and activin receptor mRNAs, both of which contain eCPEs, are detected in immunoprecipitated ElrA-mRNP complexes from eggs and embryos. In addition, this in vivo interaction requires the eCPE. Although a number of experiments failed to define a role for ElrA in cytoplasmic polyadenylation, the expression of a dominant negative ElrA protein in embryos results in an exogastrulation phenotype. The possible functions of ElrA in gastrulation are discussed.


1999 ◽  
Vol 112 (2) ◽  
pp. 157-168 ◽  
Author(s):  
L. Trinkle-Mulcahy ◽  
P. Ajuh ◽  
A. Prescott ◽  
F. Claverie-Martin ◽  
S. Cohen ◽  
...  

Protein phosphatase-1 (PP1) is complexed to many proteins that target it to particular subcellular locations and regulate its activity. Here, we show that ‘nuclear inhibitor of PP1’ (NIPP1), a major nuclear PP1-binding protein, shows a speckled nucleoplasmic distribution where it is colocalised with pre-mRNA splicing factors. One of these factors (Sm) is also shown to be complexed to NIPP1 in nuclear extracts. Immunodepletion of NIPP1 from nuclear extracts, or addition of a ‘dominant negative’ mutant lacking a functional PP1 binding site, greatly reduces pre-mRNA splicing activity in vitro. These findings implicate the NIPP1-PP1 complex in the control of pre-mRNA splicing.


2021 ◽  
Vol 17 (5) ◽  
pp. e1009549
Author(s):  
Thomas C. Montavon ◽  
Morgane Baldaccini ◽  
Mathieu Lefèvre ◽  
Erika Girardi ◽  
Béatrice Chane-Woon-Ming ◽  
...  

The antiviral innate immune response mainly involves type I interferon (IFN) in mammalian cells. The contribution of the RNA silencing machinery remains to be established, but several recent studies indicate that the ribonuclease DICER can generate viral siRNAs in specific conditions. It has also been proposed that type I IFN and RNA silencing could be mutually exclusive antiviral responses. In order to decipher the implication of DICER during infection of human cells with alphaviruses such as the Sindbis virus and Semliki forest virus, we determined its interactome by proteomics analysis. We show that DICER specifically interacts with several double-stranded RNA binding proteins and RNA helicases during viral infection. In particular, proteins such as DHX9, ADAR-1 and the protein kinase RNA-activated (PKR) are enriched with DICER in virus-infected cells. We demonstrate that the helicase domain of DICER is essential for this interaction and that its deletion confers antiviral properties to this protein in an RNAi-independent, PKR-dependent, manner.


2020 ◽  
Vol 477 (2) ◽  
pp. 509-524
Author(s):  
Oumayma Rouis ◽  
Cédric Broussard ◽  
François Guillonneau ◽  
Jean-Baptiste Boulé ◽  
Emmanuelle Delagoutte

DNA hemicatenanes (HCs) are four-way junctions in which one strand of a double-stranded helix is catenated with one strand of another double-stranded DNA. Frequently mentioned as DNA replication, recombination and repair intermediates, they have been proposed to participate in the spatial organization of chromosomes and in the regulation of gene expression. To explore potential roles of HCs in genome metabolism, we sought to purify proteins capable of binding specifically HCs by fractionating nuclear extracts from HeLa cells. This approach identified three RNA-binding proteins: the Tudor-staphylococcal nuclease domain 1 (SND1) protein and two proteins from the Drosophila behavior human splicing family, the paraspeckle protein component 1 and the splicing factor proline- and glutamine-rich protein. Since these proteins were partially pure after fractionation, truncated forms of these proteins were expressed in Escherichia coli and purified to near homogeneity. The specificity of their interaction with HCs was re-examined in vitro. The two truncated purified SND1 proteins exhibited specificity for HCs, opening the interesting possibility of a link between the basic transcription machinery and HC structures via SND1.


Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 181 ◽  
Author(s):  
Frances Taschuk ◽  
Sara Cherry

DEAD-box helicases are a large family of conserved RNA-binding proteins that belong to the broader group of cellular DExD/H helicases. Members of the DEAD-box helicase family have roles throughout cellular RNA metabolism from biogenesis to decay. Moreover, there is emerging evidence that cellular RNA helicases, including DEAD-box helicases, play roles in the recognition of foreign nucleic acids and the modulation of viral infection. As intracellular parasites, viruses must evade detection by innate immune sensing mechanisms and degradation by cellular machinery while also manipulating host cell processes to facilitate replication. The ability of DEAD-box helicases to recognize RNA in a sequence-independent manner, as well as the breadth of cellular functions carried out by members of this family, lead them to influence innate recognition and viral infections in multiple ways. Indeed, DEAD-box helicases have been shown to contribute to intracellular immune sensing, act as antiviral effectors, and even to be coopted by viruses to promote their replication. However, our understanding of the mechanisms underlying these interactions, as well as the cellular roles of DEAD-box helicases themselves, is limited in many cases. We will discuss the diverse roles that members of the DEAD-box helicase family play during viral infections.


Genes ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1471
Author(s):  
Michael Cargill ◽  
Rasika Venkataraman ◽  
Stanley Lee

DEAD-box RNA helicases are important regulators of RNA metabolism and have been implicated in the development of cancer. Interestingly, these helicases constitute a major recurring family of RNA-binding proteins important for protecting the genome. Current studies have provided insight into the connection between genomic stability and several DEAD-box RNA helicase family proteins including DDX1, DDX3X, DDX5, DDX19, DDX21, DDX39B, and DDX41. For each helicase, we have reviewed evidence supporting their role in protecting the genome and their suggested mechanisms. Such helicases regulate the expression of factors promoting genomic stability, prevent DNA damage, and can participate directly in the response and repair of DNA damage. Finally, we summarized the pathological and therapeutic relationship between DEAD-box RNA helicases and cancer with respect to their novel role in genome stability.


2021 ◽  
Author(s):  
Sean R Kundinger ◽  
Eric B Dammer ◽  
Luming Yin ◽  
Cheyenne Hurst ◽  
Lingyan Ping ◽  
...  

Post-translational modifications (PTMs) within splicing factor RNA-binding proteins (RBPs), such as phosphorylation, regulate several critical steps in RNA metabolism including spliceosome assembly, alternative splicing and mRNA export. Notably, the arginine-/serine-rich (RS) domains in SR proteins are densely modified by phosphorylation compared with the remainder of the proteome. Previously, we showed that dephosphorylation of SRSF2 regulated increased interactions with similar arginine-rich RBPs U1-70K and LUC7L3. In this work, we dephosphorylated nuclear extracts using phosphatase in vitro and analyzed equal amounts of detergent-soluble and -insoluble fractions by mass spectrometry-based proteomics. Correlation network analysis resolved 27 distinct modules of differentially soluble nucleoplasm proteins. We found classes of arginine-rich RBPs that decrease in solubility following dephosphorylation and enrich to the insoluble pelleted fraction, including the SR protein family and the SR-like LUC7L RBP family. Importantly, increased insolubility was not observed across broad classes of RBPs. Phosphorylation regulated SRSF2 structure, as dephosphorylated SRSF2 formed high molecular weight oligomeric species in vitro. Reciprocally, phosphorylation of SRSF2 by serine-/arginine protein kinase 2 (SRPK2) in vitro prevented high molecular weight SRSF2 species formation. Furthermore, we pharmacologically inhibited SRPKs in mammalian cells and observed increased cytoplasmic granules as well as the formation of cytoplasmic SRSF2 tubular structures that associate with microtubules by immunocytochemical staining. Collectively, these findings demonstrate that phosphorylation may be a critical modification that prevents arginine-rich RBP insolubility and oligomerization.


2014 ◽  
Vol 34 (6) ◽  
Author(s):  
Shengbing Zang ◽  
Ting-Yu Lin ◽  
Xinji Chen ◽  
Marieta Gencheva ◽  
Alain N. S. Newo ◽  
...  

Using biochemical, mutation, and cellular analyses, we characterized important domains involved in the functionality of a RNA-binding protein in RNA splicing. We also showed the similarity and difference between yeast and human counterparts.


2019 ◽  
Author(s):  
Oumayma Rouis ◽  
Cédric Broussard ◽  
François Guillonneau ◽  
Jean-Baptiste Boulé ◽  
Emmanuelle Delagoutte

AbstractDNA hemicatenanes (HCs) are DNA structures in which one strand of a double stranded helix passes through the two strands of another double stranded DNA. Frequently mentioned as DNA replication, recombination and repair intermediates, they have been proposed to participate in the spatial organization of chromosomes and in the regulation of gene expression. To explore potential roles of HCs in genome metabolism, proteins capable of binding specifically HCs were purified by fractionating nuclear extracts from Hela cells. This approach identified three RNA-binding proteins: the Tudor-Staphylococcal Nuclease Domain 1 (SND1) protein and two proteins from the Drosophila behavior human splicing family, the ParaSpeckle Protein Component 1 and the Splicing Factor Proline- and Glutamine- rich protein. Since these proteins were partially pure after fractionation, truncated forms of these proteins were expressed in E. coli and purified to near homogeneity. The specificity of their interaction with HCs was re-examined in vitro. The two truncated purified SND1 proteins exhibited a high specificity for HCs, suggesting a role of SND1 protein in targeting the basic transcription machinery to HC structures.


2020 ◽  
Author(s):  
Thomas C. Montavon ◽  
Morgane Baldaccini ◽  
Mathieu Lefèvre ◽  
Erika Girardi ◽  
Béatrice Chane-Woon-Ming ◽  
...  

AbstractThe antiviral innate immune response mainly involves type I interferon (IFN) in mammalian cells. The contribution of the RNA silencing machinery remains to be established, but several recent studies indicate that the ribonuclease DICER can generate viral siRNAs in specific conditions. It has also been proposed that type I IFN and RNA silencing could be mutually exclusive antiviral responses. In order to decipher the implication of DICER during infection of human cells with the Sindbis virus, we determined its interactome by proteomics analysis. We show that DICER specifically interacts with several double-stranded RNA binding proteins and RNA helicases during viral infection. In particular, proteins such as DHX9, ADAR-1 and the protein kinase RNA-activated (PKR) are enriched with DICER in virus-infected cells. We demonstrate the importance of DICER helicase domain in its interaction with PKR and showed that it has functional consequences for the cellular response to viral infection.


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