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Sample records for antisense rna regulates

  1. A riboswitch-regulated antisense RNA in Listeria monocytogenes.

    PubMed

    Mellin, J R; Tiensuu, Teresa; Bécavin, Christophe; Gouin, Edith; Johansson, Jörgen; Cossart, Pascale

    2013-08-01

    Riboswitches are ligand-binding elements located in 5' untranslated regions of messenger RNAs, which regulate expression of downstream genes. In Listeria monocytogenes, a vitamin B12-binding (B12) riboswitch was identified, not upstream of a gene but downstream, and antisense to the adjacent gene, pocR, suggesting it might regulate pocR in a nonclassical manner. In Salmonella enterica, PocR is a transcription factor that is activated by 1,2-propanediol, and subsequently activates expression of the pdu genes. The pdu genes mediate propanediol catabolism and are implicated in pathogenesis. As enzymes involved in propanediol catabolism require B12 as a cofactor, we hypothesized that the Listeria B12 riboswitch might be involved in pocR regulation. Here we demonstrate that the B12 riboswitch is transcribed as part of a noncoding antisense RNA, herein named AspocR. In the presence of B12, the riboswitch induces transcriptional termination, causing aspocR to be transcribed as a short transcript. In contrast, in the absence of B12, aspocR is transcribed as a long antisense RNA, which inhibits pocR expression. Regulation by AspocR ensures that pocR, and consequently the pdu genes, are maximally expressed only when both propanediol and B12 are present. Strikingly, AspocR can inhibit pocR expression in trans, suggesting it acts through a direct interaction with pocR mRNA. Together, this study demonstrates how pocR and the pdu genes can be regulated by B12 in bacteria and extends the classical definition of riboswitches from elements governing solely the expression of mRNAs to a wider role in controlling transcription of noncoding RNAs. PMID:23878253

  2. MYCNOS functions as an antisense RNA regulating MYCN

    PubMed Central

    Vadie, Nadia; Saayman, Sheena; Lenox, Alexandra; Ackley, Amanda; Clemson, Mathew; Burdach, Jon; Hart, Jonathan; Vogt, Peter K; Morris, Kevin V

    2015-01-01

    Amplification or overexpression of neuronal MYC (MYCN) is associated with poor prognosis of human neuroblastoma. Three isoforms of the MYCN protein have been described as well as a protein encoded by an antisense transcript (MYCNOS) that originates from the opposite strand at the MYCN locus. Recent findings suggest that some antisense long non-coding RNAs (lncRNAs) can play a role in epigenetically regulating gene expression. Here we report that MYCNOS transcripts function as a modulator of the MYCN locus, affecting MYCN promoter usage and recruiting various proteins, including the Ras GTPase-activating protein-binding protein G3BP1, to the upstream MYCN promoter. Overexpression of MYCNOS results in a reduction of upstream MYCN promoter usage and increased MYCN expression, suggesting that the protein-coding MYCNOS also functions as a regulator of MYCN ultimately controlling MYCN transcriptional variants. The observations presented here demonstrate that protein-coding transcripts can regulate gene transcription and can tether regulatory proteins to target loci. PMID:26156430

  3. A novel antisense long noncoding RNA regulates the expression of MDC1 in bladder cancer

    PubMed Central

    Hua, Qiuhan; Chu, Haiyan; Tong, Na; Yuan, Lin; Qin, Chao; Yin, Changjun; Zhang, Zhengdong; Wang, Meilin

    2015-01-01

    Antisense long noncoding RNAs (lncRNAs) play important roles in regulating the expression of coding genes in post-transcriptional level. However, detailed expression profile of lncRNAs and functions of antisense lncRNAs in bladder cancer remains unclear. To investigate regulation of lncRNAs in bladder cancer and demonstrate their functions, we performed lncRNAs microarray analysis in 3 paired bladder cancer tissues. Further molecular assays were conducted to determine the potential role of identified antisense lncRNA MDC1-AS. As a result, a series of lncRNAs were differentially expressed in bladder cancer tissues in microarray screen. In a larger size of samples validation, we found that the expression levels of MDC1-AS and MDC1 was down-regulated in bladder cancer. After over-expression of MDC1-AS, increased levels of MDC1 were observed in bladder cancer cells. We also found a remarkably inhibitory role of antisense lncRNA MDC1-AS on malignant cell behaviors in bladder cancer cells EJ and T24. Subsequently, knockdown of MDC1 revealed that suppressing role of MDC1-AS was attributed to up-regulation of MDC1. In summary, we have identified a novel antisense lncRNA MDC1-AS, which may participate in bladder cancer through up-regulation of its antisense tumor-suppressing gene MDC1. Further studies should be conducted to demonstrate detailed mechanism of our findings. PMID:25514464

  4. An HIV-Encoded Antisense Long Noncoding RNA Epigenetically Regulates Viral Transcription

    PubMed Central

    Saayman, Sheena; Ackley, Amanda; Turner, Anne-Marie W; Famiglietti, Marylinda; Bosque, Alberto; Clemson, Matthew; Planelles, Vicente; Morris, Kevin V

    2014-01-01

    The abundance of long noncoding RNAs (lncRNAs) and their wide range of functional roles in human cells are fast becoming realized. Importantly, lncRNAs have been identified as epigenetic modulators and consequently play a pivotal role in the regulation of gene expression. A human immunodeficiency virus-encoded antisense RNA transcript has recently been reported and we sought to characterize this RNA and determine its potential role in viral transcription regulation. The intrinsic properties of this human immunodeficiency virus-expressed lncRNA were characterized and the data presented here suggest that it functions as an epigenetic brake to modulate viral transcription. Suppression of this long antisense transcript with small single-stranded antisense RNAs resulted in the activation of viral gene expression. This lncRNA was found to localize to the 5′ long-term repeats (LTR) and to usurp components of endogenous cellular pathways that are involved in lncRNA directed epigenetic gene silencing. Collectively, we find that this viral expressed antisense lncRNA is involved in modulating human immunodeficiency virus gene expression and that this regulatory effect is due to an alteration in the epigenetic landscape at the viral promoter. PMID:24576854

  5. RNA synthetic biology inspired from bacteria: construction of transcription attenuators under antisense regulation

    NASA Astrophysics Data System (ADS)

    Dawid, Alexandre; Cayrol, Bastien; Isambert, Hervé

    2009-06-01

    Among all biopolymers, ribonucleic acids or RNA have unique functional versatility, which led to the early suggestion that RNA alone (or a closely related biopolymer) might have once sustained a primitive form of life based on a single type of biopolymer. This has been supported by the demonstration of processive RNA-based replication and the discovery of 'riboswitches' or RNA switches, which directly sense their metabolic environment. In this paper, we further explore the plausibility of this 'RNA world' scenario and show, through synthetic molecular design guided by advanced RNA simulations, that RNA can also perform elementary regulation tasks on its own. We demonstrate that RNA synthetic regulatory modules directly inspired from bacterial transcription attenuators can efficiently activate or repress the expression of other RNA by merely controlling their folding paths 'on the fly' during transcription through simple RNA-RNA antisense interaction. Factors, such as NTP concentration and RNA synthesis rate, affecting the efficiency of this kinetic regulation mechanism are also studied and discussed in the light of evolutionary constraints. Overall, this suggests that direct coupling among synthesis, folding and regulation of RNAs may have enabled the early emergence of autonomous RNA-based regulation networks in absence of both DNA and protein partners.

  6. Transcriptional regulation of Oct4 by a long non-coding RNA antisense to Oct4-pseudogene 5.

    PubMed

    Hawkins, Peter G; Morris, Kevin V

    2010-11-01

    Long non-coding RNAs (lncRNAs) have been shown to epigenetically regulate certain genes in human cells. Here we report evidence for the involvement of an antisense lncRNA in the transcriptional regulation of the pluripotency-associated factor Oct4. When an lncRNA antisense to Oct4-pseudogene 5 was suppressed, transcription of Oct4 and Oct4 pseudogenes 4 and 5 was observed to increase. This increase correlated with a loss of silent state epigenetic marks and the histone methyltransferase Ezh2 at the Oct4 promoter. We observed this lncRNA to interact with nucleolin and PURA, a 35 kD single-stranded DNA and RNA binding protein, and found that these proteins may act to negatively regulate this antisense transcript. PMID:21151833

  7. Antisense RNA regulation and application in the development of novel antibiotics to combat multidrug resistant bacteria.

    PubMed

    Ji, Yinduo; Lei, Ting

    2013-01-01

    Despite the availability of antibiotics and vaccines, infectious diseases remain one of most dangerous threats to humans and animals. The overuse and misuse of antibacterial agents have led to the emergence of multidrug resistant bacterial pathogens. Bacterial cells are often resilient enough to survive in even the most extreme environments. To do so, the organisms have evolved different mechanisms, including a variety of two-component signal transduction systems, which allow the bacteria to sense the surrounding environment and regulate gene expression in order to adapt and respond to environmental stimuli. In addition, some bacteria evolve resistance to antibacterial agents while many bacterial cells are able to acquire resistance genes from other bacterial species to enable them to survive in the presence of toxic antimicrobial agents. The crisis of antimicrobial resistance is an unremitting menace to human health and a burden on public health. The rapid increase in antimicrobial resistant organisms and limited options for development of new classes of antibiotics heighten the urgent need to develop novel potent antibacterial therapeutics in order to combat multidrug resistant infections. In this review, we introduce the regulatory mechanisms of antisense RNA and significant applications of regulated antisense RNA interference technology in early drug discovery. This includes the identification and evaluation of drug targets in vitro and in vivo, the determination of mode of action for antibiotics and new antibacterial agents, as well as the development of peptide-nucleic acid conjugates as novel antibacterials. PMID:23738437

  8. Viral escape from antisense RNA.

    PubMed

    Bull, J J; Jacobson, A; Badgett, M R; Molineux, I J

    1998-05-01

    RNA coliphage SP was propagated for several generations on a host expressing an inhibitory antisense RNA complementary to bases 31-270 of the positive-stranded genome. Phages evolved that escaped inhibition. Typically, these escape mutants contained 3-4 base substitutions, but different sequences were observed among different isolates. The mutations were located within three different types of structural features within the predicted secondary structure of SP genomic RNA: (i) hairpin loops; (ii) hairpin stems; and (iii) the 5' region of the phage genome complementary to the antisense molecule. Computer modelling of the mutant genomic RNAs showed that all of the substitutions within hairpin stems improved the Watson-Crick pairing of the stem. No major structural rearrangements were predicted for any of the mutant genomes, and most substitutions in coding regions did not alter the amino acid sequence. Although the evolved phage populations were polymorphic for substitutions, many substitutions appeared independently in two selected lines. The creation of a new, perfect, antisense RNA against an escape mutant resulted in the inhibition of that mutant but not of other escape mutants nor of the ancestral, unevolved phage. Thus, at least in this system, a population of viruses that evolved to escape from a single antisense RNA would require a cocktail of several antisense RNAs for inhibition. PMID:9643550

  9. Long noncoding RNA FGFR3-AS1 promotes osteosarcoma growth through regulating its natural antisense transcript FGFR3.

    PubMed

    Sun, Jiabing; Wang, Xuming; Fu, Chunjiang; Wang, Xiaoyu; Zou, Jilong; Hua, Hanbing; Bi, Zhenggang

    2016-05-01

    Long noncoding RNAs (lncRNAs), a new class of RNAs with no protein-coding potential, have been reported to have crucial roles in the regulation of a variety of tumors. However, the functions and molecular mechanisms of lncRNAs to osteosarcoma are still largely unknown. The purpose of this study is to examine the expression, functions and molecular mechanisms of a new lncRNA FGFR3 antisense transcript 1 (FGFR3-AS1) in osteosarcoma. The expression of FGFR3-AS1 was examined by real-time quantitative PCR. The regulation of FGFR3 by FGFR3-AS1 was examined by RNase protection assay, real-time quantitative PCR, western blotting, and luciferase reporter assay. The effects of FGFR3-AS1 on osteosarcoma cell proliferation and cell cycle were determined by Cell Counting Kit-8, Ethynyl deoxyuridine incorporation assay and flow cytometry. FGFR3-AS1 was upregulated in osteosarcoma. Increased FGFR3-AS1 expression correlates with large tumor size, advanced Enneking stage, metastasis and poor survival. Through antisense pairing with FGFR3 3'UTR, FGFR3-AS1 increases FGFR3 mRNA stability and upregulates FGFR3 expression. The expression of FGFR3-AS1 and FGFR3 is positively correlated in osteosarcoma tissues. Knockdown of FGFR3-AS1 inhibits the proliferation and cell cycle progression of osteosarcoma cells in vitro. Moreover, knockdown of FGFR3-AS1 inhibits xenograft tumor growth of osteosarcoma cells in vivo. These data demonstrate the mechanisms of how antisense noncoding RNA regulate the expression of sense genes, and show the pivotal functions of FGFR3-AS1 in osteosarcoma. PMID:27022737

  10. Data in support of transcriptional regulation and function of Fas-antisense long noncoding RNA during human erythropoiesis

    PubMed Central

    Villamizar, Olga; Chambers, Christopher B.; Mo, Yin-Yuan; Torry, Donald S.; Hofstrand, Reese; Riberdy, Janice M.; Persons, Derek A.; Wilber, Andrew

    2016-01-01

    This paper describes data related to a research article titled, “Fas-antisense long noncoding RNA is differentially expressed during maturation of human erythrocytes and confers resistance to Fas-mediated cell death” [1]. Long noncoding RNAs (lncRNAs) are increasingly appreciated for their capacity to regulate many steps of gene expression. While recent studies suggest that many lncRNAs are functional, the scope of their actions throughout human biology is largely undefined including human red blood cell development (erythropoiesis). Here we include expression data for 82 lncRNAs during early, intermediate and late stages of human erythropoiesis using a commercial qPCR Array. From these data, we identified lncRNA Fas-antisense 1 (Fas-AS1 or Saf) described in the research article. Also included are 5′ untranslated sequences (UTR) for lncRNA Saf with transcription factor target sequences identified. Quantitative RT-PCR data demonstrate relative levels of critical erythroid transcription factors, GATA-1 and KLF1, in K562 human erythroleukemia cells and maturing erythroblasts derived from human CD34+ cells. End point and quantitative RT-PCR data for cDNA prepared using random hexamers versus oligo(dT)18 revealed that lncRNA Saf is not effectively polyadenylated. Finally, we include flow cytometry histograms demonstrating Fas levels on maturing erythroblasts derived from human CD34+ cells transduced using mock conditions or with lentivirus particles encoding for Saf. PMID:27141526

  11. Data in support of transcriptional regulation and function of Fas-antisense long noncoding RNA during human erythropoiesis.

    PubMed

    Villamizar, Olga; Chambers, Christopher B; Mo, Yin-Yuan; Torry, Donald S; Hofstrand, Reese; Riberdy, Janice M; Persons, Derek A; Wilber, Andrew

    2016-06-01

    This paper describes data related to a research article titled, "Fas-antisense long noncoding RNA is differentially expressed during maturation of human erythrocytes and confers resistance to Fas-mediated cell death" [1]. Long noncoding RNAs (lncRNAs) are increasingly appreciated for their capacity to regulate many steps of gene expression. While recent studies suggest that many lncRNAs are functional, the scope of their actions throughout human biology is largely undefined including human red blood cell development (erythropoiesis). Here we include expression data for 82 lncRNAs during early, intermediate and late stages of human erythropoiesis using a commercial qPCR Array. From these data, we identified lncRNA Fas-antisense 1 (Fas-AS1 or Saf) described in the research article. Also included are 5' untranslated sequences (UTR) for lncRNA Saf with transcription factor target sequences identified. Quantitative RT-PCR data demonstrate relative levels of critical erythroid transcription factors, GATA-1 and KLF1, in K562 human erythroleukemia cells and maturing erythroblasts derived from human CD34(+) cells. End point and quantitative RT-PCR data for cDNA prepared using random hexamers versus oligo(dT)18 revealed that lncRNA Saf is not effectively polyadenylated. Finally, we include flow cytometry histograms demonstrating Fas levels on maturing erythroblasts derived from human CD34(+) cells transduced using mock conditions or with lentivirus particles encoding for Saf. PMID:27141526

  12. Antisense RNA suppression of peroxidase gene expression

    SciTech Connect

    Lagrimini, L.M.; Bradford, S.; De Leon, F.D. )

    1989-04-01

    The 5{prime} half the anionic peroxidase cDNA of tobacco was inserted into a CaMV 35S promoter/terminator expression cassette in the antisense configuration. This was inserted into the Agrobacterium-mediated plant transformation vector pCIBIO which includes kanamycin selection, transformed into two species of tobacco (N. tabacum and M. sylvestris), and plants were subsequently regenerated on kanamycin. Transgenic plants were analyzed for peroxidase expression and found to have 3-5 fold lower levels of peroxidase than wild-type plants. Isoelectric focusing demonstrated that the antisense RNA only suppressed the anionic peroxidase. Wound-induced peroxidase expression was found not to be affected by the antisense RNA. Northern blots show a greater than 5 fold suppression of anionic peroxidase mRNA in leaf tissue, and the antisense RNA was expressed at a level 2 fold over the endogenous mRNA. Plants were self-pollinated and F1 plants showed normal segregation. N. sylvestris transgenic plants with the lowest level of peroxidase are epinastic, and preliminary results indicate elevated auxin levels. Excised pith tissue from both species of transgenic plants rapidly collapse when exposed to air, while pith tissue from wild-type plants showed little change when exposed to air. Further characterization of these phenotypes is currently being made.

  13. Regulation of an antisense RNA with the transition of neonatal to IIb myosin heavy chain during postnatal development and hypothyroidism in rat skeletal muscle.

    PubMed

    Pandorf, Clay E; Jiang, Weihua; Qin, Anqi X; Bodell, Paul W; Baldwin, Kenneth M; Haddad, Fadia

    2012-04-01

    Postnatal development of fast skeletal muscle is characterized by a transition in expression of myosin heavy chain (MHC) isoforms, from primarily neonatal MHC at birth to primarily IIb MHC in adults, in a tightly coordinated manner. These isoforms are encoded by distinct genes, which are separated by ∼17 kb on rat chromosome 10. The neonatal-to-IIb MHC transition is inhibited by a hypothyroid state. We examined RNA products [mRNA, pre-mRNA, and natural antisense transcript (NAT)] of developmental and adult-expressed MHC genes (embryonic, neonatal, I, IIa, IIx, and IIb) at 2, 10, 20, and 40 days after birth in normal and thyroid-deficient rat neonates treated with propylthiouracil. We found that a long noncoding antisense-oriented RNA transcript, termed bII NAT, is transcribed from a site within the IIb-Neo intergenic region and across most of the IIb MHC gene. NATs have previously been shown to mediate transcriptional repression of sense-oriented counterparts. The bII NAT is transcriptionally regulated during postnatal development and in response to hypothyroidism. Evidence for a regulatory mechanism is suggested by an inverse relationship between IIb MHC and bII NAT in normal and hypothyroid-treated muscle. Neonatal MHC transcription is coordinately expressed with bII NAT. A comparative phylogenetic analysis also suggests that bII NAT-mediated regulation has been a conserved trait of placental mammals for most of the eutherian evolutionary history. The evidence in support of the regulatory model implicates long noncoding antisense RNA as a mechanism to coordinate the transition between neonatal and IIb MHC during postnatal development. PMID:22262309

  14. Avoidance of antisense, antiterminator tRNA anticodons in vertebrate mitochondria.

    PubMed

    Seligmann, Hervé

    2010-07-01

    Protein synthesis (translation) stops at stop codons, codons not complemented by tRNA anticodons. tRNAs matching stops, antitermination (Ter) tRNAs, prevent translational termination, producing dysfunctional proteins. Genomes avoid tRNAs with anticodons whose complement (the anticodon of the 'antisense' tRNA) matches stops. This suggests that antisense tRNAs, which also form cloverleaves, are occasionally expressed. Mitochondrial antisense tRNA expression is plausible, because both DNA strands are transcribed as single RNAs, and tRNA structures signal RNA maturation. Results describe potential antisense Ter tRNAs in mammalian mitochondrial genomes detected by tRNAscan-SE, and evidence for adaptations preventing translational antitermination: genomes possessing Ter tRNAs use less corresponding stop codons; antisense Ter tRNAs form weaker cloverleaves than homologuous non-Ter antisense tRNAs; and genomic stop codon usages decrease with stabilities of codon-anticodon interactions and of Ter tRNA cloverleaves. This suggests that antisense tRNAs frequently function in translation. Results suggest that opposite strand coding is exceptional in modern genes, yet might be frequent for mitochondrial tRNAs. This adds antisense tRNA templating to other mitochondrial tRNA functions: sense tRNA templating, formation and regulation of secondary (light strand DNA) replication origins. Antitermination probably affects mitochondrial degenerative diseases and ageing: pathogenic mutations are twice as frequent in tRNAs with antisense Ter anticodons than in other tRNAs, and species lacking mitochondrial antisense Ter tRNAs have longer mean maximal lifespans than those possessing antisense Ter tRNAs. PMID:20399828

  15. JACALIN-LECTIN LIKE1 Regulates the Nuclear Accumulation of GLYCINE-RICH RNA-BINDING PROTEIN7, Influencing the RNA Processing of FLOWERING LOCUS C Antisense Transcripts and Flowering Time in Arabidopsis1[OPEN

    PubMed Central

    Xiao, Jun; Li, Chunhua; Xu, Shujuan; Xing, Lijing; Xu, Yunyuan; Chong, Kang

    2015-01-01

    Lectins selectively recognize sugars or glycans for defense in living cells, but less is known about their roles in the development process and the functional network with other factors. Here, we show that Arabidopsis (Arabidopsis thaliana) JACALIN-LECTIN LIKE1 (AtJAC1) functions in flowering time control. Loss of function of AtJAC1 leads to precocious flowering, whereas overexpression of AtJAC1 causes delayed flowering. AtJAC1 influences flowering through regulation of the key flowering repressor gene FLOWERING LOCUS C (FLC). Genetic analysis revealed that AtJAC1’s function is mostly dependent on GLYCINE-RICH RNA-BINDING PROTEIN7 (GRP7), an upstream regulator of FLC. Biochemical and cell biological data indicated that AtJAC1 interacted physically with GRP7 specifically in the cytoplasm. AtJAC1 influences the nucleocytoplasmic distribution of GRP7, with predominant nuclear localization of GRP7 when AtJAC1 function is lost but retention of GRP7 in the cytoplasm when AtJAC1 is overexpressed. A temporal inducible assay suggested that AtJAC1’s regulation of flowering could be compromised by the nuclear accumulation of GRP7. In addition, GRP7 binds to the antisense precursor messenger RNA of FLC through a conserved RNA motif. Loss of GRP7 function leads to the elevation of total FLC antisense transcripts and reduced proximal-distal polyadenylation ratio, as well as histone methylation changes in the FLC gene body region and increased total functional sense FLC transcript. Attenuating the direct binding of GRP7 with competing artificial RNAs leads to changes of FLC antisense precursor messenger RNA processing and flowering transition. Taken together, our study indicates that AtJAC1 coordinates with GRP7 in shaping plant development through the regulation of RNA processing in Arabidopsis. PMID:26392261

  16. Divergently overlapping cis-encoded antisense RNA regulating toxin-antitoxin systems from E. coli: hok/sok, ldr/rdl, symE/symR.

    PubMed

    Kawano, Mitsuoki

    2012-12-01

    Toxin-antitoxin (TA) systems are categorized into three classes based on the type of antitoxin. In type I TA systems, the antitoxin is a small antisense RNA that inhibits translation of small toxic proteins by binding to the corresponding mRNAs. Those type I TA systems were originally identified as plasmid stabilization modules rendering a post-segregational killing (PSK) effect on the host cells. The type I TA loci also exist on the Escherichia coli chromosome but their biological functions are less clear. Genetic organization and regulatory elements of hok/sok and ldr/rdl families are very similar and the toxins are predicted to contain a transmembrane domain, but otherwise share no detectable sequence similarity. This review will give an overview of the type I TA modules of E. coli K-12, especially hok/sok, ldr/rdl and SOS-inducible symE/symR systems, which are regulated by divergently overlapping cis-encoded antisense RNAs. PMID:23131729

  17. Neighboring Gene Regulation by Antisense Long Non-Coding RNAs

    PubMed Central

    Villegas, Victoria E.; Zaphiropoulos, Peter G.

    2015-01-01

    Antisense transcription, considered until recently as transcriptional noise, is a very common phenomenon in human and eukaryotic transcriptomes, operating in two ways based on whether the antisense RNA acts in cis or in trans. This process can generate long non-coding RNAs (lncRNAs), one of the most diverse classes of cellular transcripts, which have demonstrated multifunctional roles in fundamental biological processes, including embryonic pluripotency, differentiation and development. Antisense lncRNAs have been shown to control nearly every level of gene regulation—pretranscriptional, transcriptional and posttranscriptional—through DNA–RNA, RNA–RNA or protein–RNA interactions. This review is centered on functional studies of antisense lncRNA-mediated regulation of neighboring gene expression. Specifically, it addresses how these transcripts interact with other biological molecules, nucleic acids and proteins, to regulate gene expression through chromatin remodeling at the pretranscriptional level and modulation of transcriptional and post-transcriptional processes by altering the sense mRNA structure or the cellular compartmental distribution, either in the nucleus or the cytoplasm. PMID:25654223

  18. rasiRNA pathway controls antisense expression of Drosophila telomeric retrotransposons in the nucleus

    PubMed Central

    Shpiz, Sergey; Kwon, Dmitry; Rozovsky, Yakov; Kalmykova, Alla

    2009-01-01

    Telomeres in Drosophila are maintained by the specialized telomeric retrotransposons HeT-A, TART and TAHRE. Sense transcripts of telomeric retroelements were shown to be the targets of a specialized RNA-interference mechanism, a repeat-associated short interfering (rasi)RNA-mediated system. Antisense rasiRNAs play a key role in this mechanism, highlighting the importance of antisense expression in retrotransposon silencing. Previously, bidirectional transcription was reported for the telomeric element TART. Here, we show that HeT-A is also bidirectionally transcribed, and HeT-A antisense transcription in ovaries is regulated by a promoter localized within its 3′ untranslated region. A remarkable feature of noncoding HeT-A antisense transcripts is the presence of multiple introns. We demonstrate that sense and antisense HeT-A-specific rasiRNAs are present in the same tissue, indicating that transcripts of both directions may be considered as natural targets of the rasiRNA pathway. We found that the expression of antisense transcripts of telomeric elements is regulated by the RNA silencing machinery, suggesting rasiRNA-mediated interplay between sense and antisense transcripts in the cell. Finally, this regulation occurs in the nucleus since disruption of the rasiRNA pathway leads to an accumulation of TART and HeT-A transcripts in germ cell nuclei. PMID:19036789

  19. The role of antisense long noncoding RNA in small RNA-triggered gene activation

    PubMed Central

    Zhang, Xizhe; Li, Haitang; Rossi, John J.

    2014-01-01

    Long noncoding RNAs (lncRNAs) are known to regulate neighboring protein-coding genes by directing chromatin remodeling complexes, imprinting, and X-chromosome inactivation. In this study, we explore the function of lncRNAs in small RNA-triggered transcriptional gene activation (TGA), a process in which microRNAs (miRNAs) or small interfering RNAs (siRNAs) associated with Argonaute (Ago) proteins induce chromatin remodeling and gene activation at promoters with sequence complementarity. We designed a model system with different lncRNA and chromatin environments to elucidate the molecular mechanisms required for mammalian TGA. Using RNA-fluorescence in situ hybridization (FISH) and rapid amplification of cDNA ends (RACE)-PCR, we demonstrated that small RNA-triggered TGA occurs at sites where antisense lncRNAs are transcribed through the reporter gene and promoter. Small RNA-induced TGA coincided with the enrichment of Ago2 at the promoter region, but Ago2-mediated cleavage of antisense lncRNAs was not observed. Moreover, we examined the allele-specific effects of lncRNAs through a Cre-induced inversion of a poly(A) sequence that was designed to block the transcription of antisense lncRNAs through the reporter gene region in an inducible and reversible manner. Termination of nascent antisense lncRNAs abrogated gene activation triggered by small RNAs, and only allele-specific cis-acting antisense lncRNAs, but not trans-acting lncRNAs, were capable of rescuing TGA. Hence, this model revealed that antisense lncRNAs can mediate TGA in cis and not in trans, serving as a molecular scaffold for a small RNA–Ago2 complex and chromatin remodeling. PMID:25344398

  20. RNA therapeutics: RNAi and antisense mechanisms and clinical applications

    PubMed Central

    Chery, Jessica; Näär, Anders

    2016-01-01

    RNA therapeutics refers to the use of oligonucleotides to target primarily ribonucleic acids (RNA) for therapeutic efforts or in research studies to elucidate functions of genes. Oligonucleotides are distinct from other pharmacological modalities, such as small molecules and antibodies that target mainly proteins, due to their mechanisms of action and chemical properties. Nucleic acids come in two forms: deoxyribonucleic acids (DNA) and ribonucleic acids (RNA). Although DNA is more stable, RNA offers more structural variety ranging from messenger RNA (mRNA) that codes for protein to non-coding RNAs, microRNA (miRNA), transfer RNA (tRNA), short interfering RNAs (siRNAs), ribosomal RNA (rRNA), and long-noncoding RNAs (lncRNAs). As our understanding of the wide variety of RNAs deepens, researchers have sought to target RNA since >80% of the genome is estimated to be transcribed. These transcripts include non-coding RNAs such as miRNAs and siRNAs that function in gene regulation by playing key roles in the transfer of genetic information from DNA to protein, the final product of the central dogma in biology1. Currently there are two main approaches used to target RNA: double stranded RNA-mediated interference (RNAi) and antisense oligonucleotides (ASO). Both approaches are currently in clinical trials for targeting of RNAs involved in various diseases, such as cancer and neurodegeneration. In fact, ASOs targeting spinal muscular atrophy and amyotrophic lateral sclerosis have shown positive results in clinical trials2. Advantages of ASOs include higher affinity due to the development of chemical modifications that increase affinity, selectivity while decreasing toxicity due to off-target effects. This review will highlight the major therapeutic approaches of RNA medicine currently being applied with a focus on RNAi and ASOs. PMID:27570789

  1. Strand-Specific RNA-Seq Reveals Ordered Patterns of Sense and Antisense Transcription in Bacillus anthracis

    PubMed Central

    Passalacqua, Karla D.; Varadarajan, Anjana; Weist, Charlotte; Ondov, Brian D.; Byrd, Benjamin; Read, Timothy D.; Bergman, Nicholas H.

    2012-01-01

    Background Although genome-wide transcriptional analysis has been used for many years to study bacterial gene expression, many aspects of the bacterial transcriptome remain undefined. One example is antisense transcription, which has been observed in a number of bacteria, though the function of antisense transcripts, and their distribution across the bacterial genome, is still unclear. Methodology/Principal Findings Single-stranded RNA-seq results revealed a widespread and non-random pattern of antisense transcription covering more than two thirds of the B. anthracis genome. Our analysis revealed a variety of antisense structural patterns, suggesting multiple mechanisms of antisense transcription. The data revealed several instances of sense and antisense expression changes in different growth conditions, suggesting that antisense transcription may play a role in the ways in which B. anthracis responds to its environment. Significantly, genome-wide antisense expression occurred at consistently higher levels on the lagging strand, while the leading strand showed very little antisense activity. Intrasample gene expression comparisons revealed a gene dosage effect in all growth conditions, where genes farthest from the origin showed the lowest overall range of expression for both sense and antisense directed transcription. Additionally, transcription from both strands was verified using a novel strand-specific assay. The variety of structural patterns we observed in antisense transcription suggests multiple mechanisms for this phenomenon, suggesting that some antisense transcription may play a role in regulating the expression of key genes, while some may be due to chromosome replication dynamics and transcriptional noise. Conclusions/Significance Although the variety of structural patterns we observed in antisense transcription suggest multiple mechanisms for antisense expression, our data also clearly indicate that antisense transcription may play a genome-wide role

  2. Natural Antisense Transcripts and Long Non-Coding RNA in Neurospora crassa

    PubMed Central

    Arthanari, Yamini; Heintzen, Christian; Griffiths-Jones, Sam; Crosthwaite, Susan K.

    2014-01-01

    The prevalence of long non-coding RNAs (lncRNA) and natural antisense transcripts (NATs) has been reported in a variety of organisms. While a consensus has yet to be reached on their global importance, an increasing number of examples have been shown to be functional, regulating gene expression at the transcriptional and post-transcriptional level. Here, we use RNA sequencing data from the ABI SOLiD platform to identify lncRNA and NATs obtained from samples of the filamentous fungus Neurospora crassa grown under different light and temperature conditions. We identify 939 novel lncRNAs, of which 477 are antisense to annotated genes. Across the whole dataset, the extent of overlap between sense and antisense transcripts is large: 371 sense/antisense transcripts are complementary over 500 nts or more and 236 overlap by more than 1000 nts. Most prevalent are 3′ end overlaps between convergently transcribed sense/antisense pairs, but examples of divergently transcribed pairs and nested transcripts are also present. We confirm the expression of a subset of sense/antisense transcript pairs by qPCR. We examine the size, types of overlap and expression levels under the different environmental stimuli of light and temperature, and identify 11 lncRNAs that are up-regulated in response to light. We also find differences in transcript length and the position of introns between protein-coding transcripts that have antisense expression and transcripts with no antisense expression. These results demonstrate the ability of N. crassa lncRNAs and NATs to be regulated by different environmental stimuli and provide the scope for further investigation into the function of NATs. PMID:24621812

  3. Functionalization of an Antisense Small RNA

    PubMed Central

    Rodrigo, Guillermo; Prakash, Satya; Cordero, Teresa; Kushwaha, Manish; Jaramillo, Alfonso

    2016-01-01

    In order to explore the possibility of adding new functions to preexisting genes, we considered a framework of riboregulation. We created a new riboregulator consisting of the reverse complement of a known riboregulator. Using computational design, we engineered a cis-repressing 5′ untranslated region that can be activated by this new riboregulator. As a result, both RNAs can orthogonally trans-activate translation of their cognate, independent targets. The two riboregulators can also repress each other by antisense interaction, although not symmetrically. Our work highlights that antisense small RNAs can work as regulatory agents beyond the antisense paradigm and that, hence, they could be interfaced with other circuits used in synthetic biology. PMID:26756967

  4. Non-coding RNA and Antisense RNA. Nature's Trash or Treasure?

    PubMed Central

    Knowling, Stuart; Morris, Kevin V.

    2011-01-01

    Although control of cellular function has classically been considered the responsibility of proteins, research over the last decade has elucidated many roles for RNA in regulation of not only the proteins that control cellular functions but also for the cellular functions themselves. In parallel to this advancement in knowledge about the regulatory roles of RNA there has been an explosion of knowledge about the role that epigenetics plays in controlling not only long-term cellular fate but also the short-term regulatory control of genes. Of particular interest is the crossover between these two worlds, a world where RNA can act out its part and subsequently elicit chromatin modifications that alter cellular function. Two main categories of RNA are examined here, non-coding RNA and antisense RNA both of which perform vital functions in controlling numerous genes, proteins and RNA itself. As the activities of non-coding and antisense RNA in both normal and aberrant cellular function are elucidated, so does the number of possible targets for pharmacopeic intervention. PMID:21843589

  5. Natural antisense RNA promotes 3′ end processing and maturation of MALAT1 lncRNA

    PubMed Central

    Zong, Xinying; Nakagawa, Shinichi; Freier, Susan M.; Fei, Jingyi; Ha, Taekjip; Prasanth, Supriya G.; Prasanth, Kannanganattu V.

    2016-01-01

    The RNase P-mediated endonucleolytic cleavage plays a crucial role in the 3′ end processing and cellular accumulation of MALAT1, a nuclear-retained long noncoding RNA that promotes malignancy. The regulation of this cleavage event is largely undetermined. Here we characterize a broadly expressed natural antisense transcript at the MALAT1 locus, designated as TALAM1, that positively regulates MALAT1 levels by promoting the 3′ end cleavage and maturation of MALAT1 RNA. TALAM1 RNA preferentially localizes at the site of transcription, and also interacts with MALAT1 RNA. Depletion of TALAM1 leads to defects in the 3′ end cleavage reaction and compromises cellular accumulation of MALAT1. Conversely, overexpression of TALAM1 facilitates the cleavage reaction in trans. Interestingly, TALAM1 is also positively regulated by MALAT1 at the level of both transcription and RNA stability. Together, our data demonstrate a novel feed-forward positive regulatory loop that is established to maintain the high cellular levels of MALAT1, and also unravel the existence of sense-antisense mediated regulatory mechanism for cellular lncRNAs that display RNase P-mediated 3′ end processing. PMID:26826711

  6. An Xist-activating antisense RNA required for X-chromosome inactivation

    PubMed Central

    Sarkar, Mrinal K.; Gayen, Srimonta; Kumar, Surinder; Maclary, Emily; Buttigieg, Emily; Hinten, Michael; Kumari, Archana; Harris, Clair; Sado, Takashi; Kalantry, Sundeep

    2015-01-01

    The transcriptional imbalance due to the difference in the number of X chromosomes between male and female mammals is remedied through X-chromosome inactivation, the epigenetic transcriptional silencing of one of the two X chromosomes in females. The X-linked Xist long non-coding RNA functions as an X inactivation master regulator; Xist is selectively upregulated from the prospective inactive X chromosome and is required in cis for X inactivation. Here we discover an Xist antisense long non-coding RNA, XistAR (Xist Activating RNA), which is encoded within exon 1 of the mouse Xist gene and is transcribed only from the inactive X chromosome. Selective truncation of XistAR, while sparing the overlapping Xist RNA, leads to a deficiency in Xist RNA expression in cis during the initiation of X inactivation. Thus, the Xist gene carries within its coding sequence an antisense RNA that drives Xist expression. PMID:26477563

  7. Repair of Thalassemic Human β -globin mRNA in Mammalian Cells by Antisense Oligonucleotides

    NASA Astrophysics Data System (ADS)

    Sierakowska, Halina; Sambade, Maria J.; Agrawal, Sudhir; Kole, Ryszard

    1996-11-01

    In one form of β -thalassemia, a genetic blood disorder, a mutation in intron 2 of the β -globin gene (IVS2-654) causes aberrant splicing of β -globin pre-mRNA and, consequently, β -globin deficiency. Treatment of mammalian cells stably expressing the IVS2-654 human β -globin gene with antisense oligonucleotides targeted at the aberrant splice sites restored correct splicing in a dose-dependent fashion, generating correct human β -globin mRNA and polypeptide. Both products persisted for up to 72 hr posttreatment. The oligonucleotides modified splicing by a true antisense mechanism without overt unspecific effects on cell growth and splicing of other pre-mRNAs. This novel approach in which antisense oligonucleotides are used to restore rather than to down-regulate the activity of the target gene is applicable to other splicing mutants and is of potential clinical interest.

  8. Natural antisense transcripts regulate the neuronal stress response and excitability

    PubMed Central

    Zheng, Xingguo; Valakh, Vera; DiAntonio, Aaron; Ben-Shahar, Yehuda

    2014-01-01

    Neurons regulate ionic fluxes across their plasma membrane to maintain their excitable properties under varying environmental conditions. However, the mechanisms that regulate ion channels abundance remain poorly understood. Here we show that pickpocket 29 (ppk29), a gene that encodes a Drosophila degenerin/epithelial sodium channel (DEG/ENaC), regulates neuronal excitability via a protein-independent mechanism. We demonstrate that the mRNA 3′UTR of ppk29 affects neuronal firing rates and associated heat-induced seizures by acting as a natural antisense transcript (NAT) that regulates the neuronal mRNA levels of seizure (sei), the Drosophila homolog of the human Ether-à-go-go Related Gene (hERG) potassium channel. We find that the regulatory impact of ppk29 mRNA on sei is independent of the sodium channel it encodes. Thus, our studies reveal a novel mRNA dependent mechanism for the regulation of neuronal excitability that is independent of protein-coding capacity. DOI: http://dx.doi.org/10.7554/eLife.01849.001 PMID:24642409

  9. Evolution of the Antisense Overlap between Genes for Thyroid Hormone Receptor and Rev-erbα and Characterization of an Exonic G-Rich Element That Regulates Splicing of TRα2 mRNA

    PubMed Central

    Munroe, Stephen H.; Morales, Christopher H.; Duyck, Tessa H.; Waters, Paul D.

    2015-01-01

    The α-thyroid hormone receptor gene (TRα) codes for two functionally distinct proteins: TRα1, the α-thyroid hormone receptor; and TRα2, a non-hormone-binding variant. The final exon of TRα2 mRNA overlaps the 3’ end of Rev-erbα mRNA, which encodes another nuclear receptor on the opposite strand of DNA. To understand the evolution of this antisense overlap, we sequenced these genes and mRNAs in the platypus Orthorhynchus anatinus. Despite its strong homology with other mammals, the platypus TRα/Rev-erbα locus lacks elements essential for expression of TRα2. Comparative analysis suggests that alternative splicing of TRα2 mRNA expression evolved in a stepwise fashion before the divergence of eutherian and marsupial mammals. A short G-rich element (G30) located downstream of the alternative 3’splice site of TRα2 mRNA and antisense to the 3’UTR of Rev-erbα plays an important role in regulating TRα2 splicing. G30 is tightly conserved in eutherian mammals, but is absent in marsupials and monotremes. Systematic deletions and substitutions within G30 have dramatically different effects on TRα2 splicing, leading to either its inhibition or its enhancement. Mutations that disrupt one or more clusters of G residues enhance splicing two- to three-fold. These results suggest the G30 sequence can adopt a highly structured conformation, possibly a G-quadruplex, and that it is part of a complex splicing regulatory element which exerts both positive and negative effects on TRα2 expression. Since mutations that strongly enhance splicing in vivo have no effect on splicing in vitro, it is likely that the regulatory role of G30 is mediated through linkage of transcription and splicing. PMID:26368571

  10. Evolution of the Antisense Overlap between Genes for Thyroid Hormone Receptor and Rev-erbα and Characterization of an Exonic G-Rich Element That Regulates Splicing of TRα2 mRNA.

    PubMed

    Munroe, Stephen H; Morales, Christopher H; Duyck, Tessa H; Waters, Paul D

    2015-01-01

    The α-thyroid hormone receptor gene (TRα) codes for two functionally distinct proteins: TRα1, the α-thyroid hormone receptor; and TRα2, a non-hormone-binding variant. The final exon of TRα2 mRNA overlaps the 3' end of Rev-erbα mRNA, which encodes another nuclear receptor on the opposite strand of DNA. To understand the evolution of this antisense overlap, we sequenced these genes and mRNAs in the platypus Orthorhynchus anatinus. Despite its strong homology with other mammals, the platypus TRα/Rev-erbα locus lacks elements essential for expression of TRα2. Comparative analysis suggests that alternative splicing of TRα2 mRNA expression evolved in a stepwise fashion before the divergence of eutherian and marsupial mammals. A short G-rich element (G30) located downstream of the alternative 3'splice site of TRα2 mRNA and antisense to the 3'UTR of Rev-erbα plays an important role in regulating TRα2 splicing. G30 is tightly conserved in eutherian mammals, but is absent in marsupials and monotremes. Systematic deletions and substitutions within G30 have dramatically different effects on TRα2 splicing, leading to either its inhibition or its enhancement. Mutations that disrupt one or more clusters of G residues enhance splicing two- to three-fold. These results suggest the G30 sequence can adopt a highly structured conformation, possibly a G-quadruplex, and that it is part of a complex splicing regulatory element which exerts both positive and negative effects on TRα2 expression. Since mutations that strongly enhance splicing in vivo have no effect on splicing in vitro, it is likely that the regulatory role of G30 is mediated through linkage of transcription and splicing. PMID:26368571

  11. Sense and Antisense DMPK RNA Foci Accumulate in DM1 Tissues during Development

    PubMed Central

    Michel, Lise; Huguet-Lachon, Aline; Gourdon, Geneviève

    2015-01-01

    Myotonic dystrophy type 1 (DM1) is caused by an unstable expanded CTG repeat located within the DMPK gene 3’UTR. The nature, severity and age at onset of DM1 symptoms are very variable in patients. Different forms of the disease are described, among which the congenital form (CDM) is the most severe. Molecular mechanisms of DM1 are well characterized for the adult form and involve accumulation of mutant DMPK RNA forming foci in the nucleus. These RNA foci sequester proteins from the MBNL family and deregulate CELF proteins. These proteins are involved in many cellular mechanisms such as alternative splicing, transcriptional, translational and post-translational regulation miRNA regulation as well as mRNA polyadenylation and localization. All these mechanisms can be impaired in DM1 because of the deregulation of CELF and MBNL functions. The mechanisms involved in CDM are not clearly described. In order to get insight into the mechanisms underlying CDM, we investigated if expanded RNA nuclear foci, one of the molecular hallmarks of DM1, could be detected in human DM1 fetal tissues, as well as in embryonic and neonatal tissues from transgenic mice carrying the human DMPK gene with an expanded CTG repeat. We observed very abundant RNA foci formed by sense DMPK RNA and, to a lesser extent, antisense DMPK RNA foci. Sense DMPK RNA foci clearly co-localized with MBNL1 and MBNL2 proteins. In addition, we studied DMPK sense and antisense expression during development in the transgenic mice. We found that DMPK sense and antisense transcripts are expressed from embryonic and fetal stages in heart, muscle and brain and are regulated during development. These results suggest that mechanisms underlying DM1 and CDM involved common players including toxic expanded RNA forming numerous nuclear foci at early stages during development. PMID:26339785

  12. Antisense RNA-based High-Throughput Screen System for Directed Evolution of Quorum Quenching Enzymes.

    PubMed

    Han, Sang-Soo; Park, Won-Ji; Kim, Hak-Sung; Kim, Geun-Joong

    2015-11-20

    Quorum quenching (QQ) enzymes, which disrupt the quorum sensing signaling process, have attracted considerable attention as new antimicrobial agents. However, their low catalytic efficiency for quorum sensing molecules remains a challenge. Herein, we present an antisense RNA-based high-throughput screen system for directed evolution of a quorum quenching enzyme. The screening system was constructed by incorporating an antisense RNA (RyhB) into a synthetic module to quantitatively regulate the expression of a reporter gene fused with a sense RNA (sodB). To control the expression of a reporter gene in response to the catalytic activity of a quorum quenching enzyme, the region of interaction and mode between a pair of antisense (RyhB) and sense (sodB) RNAs was designed and optimized through the prediction of the secondary structure of the RNA pair. The screening system constructed was shown to lead to a significant reduction in the false-positive rate (average 42%) in the screening of N-acyl-homoserine lactonase (AiiA) with increased catalytic activity, resulting in a true-positive frequency of up to 76%. The utility and efficiency of the screening system were demonstrated by selecting an AiiA with 31-fold higher catalytic efficiency than the wild-type in three rounds of directed evolution. The present approach can be widely used for the screening of quorum quenching enzymes with the desired catalytic property, as well as for a synthetic network for a stringent regulation of the gene expression. PMID:26366664

  13. RNA sequencing uncovers antisense RNAs and novel small RNAs in Streptococcus pyogenes

    PubMed Central

    Le Rhun, Anaïs; Beer, Yan Yan; Reimegård, Johan; Chylinski, Krzysztof; Charpentier, Emmanuelle

    2016-01-01

    ABSTRACT Streptococcus pyogenes is a human pathogen responsible for a wide spectrum of diseases ranging from mild to life-threatening infections. During the infectious process, the temporal and spatial expression of pathogenicity factors is tightly controlled by a complex network of protein and RNA regulators acting in response to various environmental signals. Here, we focus on the class of small RNA regulators (sRNAs) and present the first complete analysis of sRNA sequencing data in S. pyogenes. In the SF370 clinical isolate (M1 serotype), we identified 197 and 428 putative regulatory RNAs by visual inspection and bioinformatics screening of the sequencing data, respectively. Only 35 from the 197 candidates identified by visual screening were assigned a predicted function (T-boxes, ribosomal protein leaders, characterized riboswitches or sRNAs), indicating how little is known about sRNA regulation in S. pyogenes. By comparing our list of predicted sRNAs with previous S. pyogenes sRNA screens using bioinformatics or microarrays, 92 novel sRNAs were revealed, including antisense RNAs that are for the first time shown to be expressed in this pathogen. We experimentally validated the expression of 30 novel sRNAs and antisense RNAs. We show that the expression profile of 9 sRNAs including 2 predicted regulatory elements is affected by the endoribonucleases RNase III and/or RNase Y, highlighting the critical role of these enzymes in sRNA regulation. PMID:26580233

  14. RNA sequencing uncovers antisense RNAs and novel small RNAs in Streptococcus pyogenes.

    PubMed

    Le Rhun, Anaïs; Beer, Yan Yan; Reimegård, Johan; Chylinski, Krzysztof; Charpentier, Emmanuelle

    2016-02-01

    Streptococcus pyogenes is a human pathogen responsible for a wide spectrum of diseases ranging from mild to life-threatening infections. During the infectious process, the temporal and spatial expression of pathogenicity factors is tightly controlled by a complex network of protein and RNA regulators acting in response to various environmental signals. Here, we focus on the class of small RNA regulators (sRNAs) and present the first complete analysis of sRNA sequencing data in S. pyogenes. In the SF370 clinical isolate (M1 serotype), we identified 197 and 428 putative regulatory RNAs by visual inspection and bioinformatics screening of the sequencing data, respectively. Only 35 from the 197 candidates identified by visual screening were assigned a predicted function (T-boxes, ribosomal protein leaders, characterized riboswitches or sRNAs), indicating how little is known about sRNA regulation in S. pyogenes. By comparing our list of predicted sRNAs with previous S. pyogenes sRNA screens using bioinformatics or microarrays, 92 novel sRNAs were revealed, including antisense RNAs that are for the first time shown to be expressed in this pathogen. We experimentally validated the expression of 30 novel sRNAs and antisense RNAs. We show that the expression profile of 9 sRNAs including 2 predicted regulatory elements is affected by the endoribonucleases RNase III and/or RNase Y, highlighting the critical role of these enzymes in sRNA regulation. PMID:26580233

  15. Programmable control of bacterial gene expression with the combined CRISPR and antisense RNA system

    PubMed Central

    Lee, Young Je; Hoynes-O'Connor, Allison; Leong, Matthew C.; Moon, Tae Seok

    2016-01-01

    A central goal of synthetic biology is to implement diverse cellular functions by predictably controlling gene expression. Though research has focused more on protein regulators than RNA regulators, recent advances in our understanding of RNA folding and functions have motivated the use of RNA regulators. RNA regulators provide an advantage because they are easier to design and engineer than protein regulators, potentially have a lower burden on the cell and are highly orthogonal. Here, we combine the CRISPR system from Streptococcus pyogenes and synthetic antisense RNAs (asRNAs) in Escherichia coli strains to repress or derepress a target gene in a programmable manner. Specifically, we demonstrate for the first time that the gene target repressed by the CRISPR system can be derepressed by expressing an asRNA that sequesters a small guide RNA (sgRNA). Furthermore, we demonstrate that tunable levels of derepression can be achieved (up to 95%) by designing asRNAs that target different regions of a sgRNA and by altering the hybridization free energy of the sgRNA–asRNA complex. This new system, which we call the combined CRISPR and asRNA system, can be used to reversibly repress or derepress multiple target genes simultaneously, allowing for rational reprogramming of cellular functions. PMID:26837577

  16. Inhibition of the synthesis of a cytochrome-c-oxidase subunit isoform by antisense RNA.

    PubMed

    Sandonà, D; Bisson, R

    1994-02-01

    To investigate the role of subunit VIIe, an oxygen-regulated subunit isoform of Dictyostelium discoideum cytochrome-c oxidase, the full-length cDNA was inserted into an expression vector under the control of an actin promoter in the sense and antisense orientation. The DNA constructs were used for stable transformation of the slime mold amoebae. In most of the 28 antisense clones tested, the concentration of cytochrome-c oxidase was lowered compared to the wild type, while no significant changes were found in the sense mutants. Antisense RNA was abundantly expressed, leading to a drastic reduction of the steady-state level of the endogenous subunit VIIe mRNA, which was decreased up to 20-30% the level observed in parent cells. In these transformants, the amount of the target polypeptide and cytochrome c oxidase was 40-50% and 60-70% of control, respectively. A similar decrease was found in the level of the remaining nuclear and mitochondrial subunits. Unexpectedly, these changes affected neither basal nor uncoupled cell respiration suggesting an increase of the enzyme specific activity. Hypoxia completely relieved the cytochrome-c-oxidase deficit. These results indicate that subunit VII is needed for an efficient assembly of the protein complex and provide evidence for its involvement in the modulation of the enzyme activity. PMID:8112318

  17. Strand-specific community RNA-seq reveals prevalent and dynamic antisense transcription in human gut microbiota

    PubMed Central

    Bao, Guanhui; Wang, Mingjie; Doak, Thomas G.; Ye, Yuzhen

    2015-01-01

    Metagenomics and other meta-omics approaches (including metatranscriptomics) provide insights into the composition and function of microbial communities living in different environments or animal hosts. Metatranscriptomics research provides an unprecedented opportunity to examine gene regulation for many microbial species simultaneously, and more importantly, for the majority that are unculturable microbial species, in their natural environments (or hosts). Current analyses of metatranscriptomic datasets focus on the detection of gene expression levels and the study of the relationship between changes of gene expression and changes of environment. As a demonstration of utilizing metatranscriptomics beyond these common analyses, we developed a computational and statistical procedure to analyze the antisense transcripts in strand-specific metatranscriptomic datasets. Antisense RNAs encoded on the DNA strand opposite a gene’s CDS have the potential to form extensive base-pairing interactions with the corresponding sense RNA, and can have important regulatory functions. Most studies of antisense RNAs in bacteria are rather recent, are mostly based on transcriptome analysis, and have been applied mainly to single bacterial species. Application of our approaches to human gut-associated metatranscriptomic datasets allowed us to survey antisense transcription for a large number of bacterial species associated with human beings. The ratio of protein coding genes with antisense transcription ranges from 0 to 35.8% (median = 10.0%) among 47 species. Our results show that antisense transcription is dynamic, varying between human individuals. Functional enrichment analysis revealed a preference of certain gene functions for antisense transcription, and transposase genes are among the most prominent ones (but we also observed antisense transcription in bacterial house-keeping genes). PMID:26388849

  18. Chromatin remodelling and antisense-mediated up-regulation of the developmental switch gene eud-1 control predatory feeding plasticity.

    PubMed

    Serobyan, Vahan; Xiao, Hua; Namdeo, Suryesh; Rödelsperger, Christian; Sieriebriennikov, Bogdan; Witte, Hanh; Röseler, Waltraud; Sommer, Ralf J

    2016-01-01

    Phenotypic plasticity has been suggested to act through developmental switches, but little is known about associated molecular mechanisms. In the nematode Pristionchus pacificus, the sulfatase eud-1 was identified as part of a developmental switch controlling mouth-form plasticity governing a predatory versus bacteriovorous mouth-form decision. Here we show that mutations in the conserved histone-acetyltransferase Ppa-lsy-12 and the methyl-binding-protein Ppa-mbd-2 mimic the eud-1 phenotype, resulting in the absence of one mouth-form. Mutations in both genes cause histone modification defects and reduced eud-1 expression. Surprisingly, Ppa-lsy-12 mutants also result in the down-regulation of an antisense-eud-1 RNA. eud-1 and antisense-eud-1 are co-expressed and further experiments suggest that antisense-eud-1 acts through eud-1 itself. Indeed, overexpression of the antisense-eud-1 RNA increases the eud-1-sensitive mouth-form and extends eud-1 expression. In contrast, this effect is absent in eud-1 mutants indicating that antisense-eud-1 positively regulates eud-1. Thus, chromatin remodelling and antisense-mediated up-regulation of eud-1 control feeding plasticity in Pristionchus. PMID:27487725

  19. Chromatin remodelling and antisense-mediated up-regulation of the developmental switch gene eud-1 control predatory feeding plasticity

    PubMed Central

    Serobyan, Vahan; Xiao, Hua; Namdeo, Suryesh; Rödelsperger, Christian; Sieriebriennikov, Bogdan; Witte, Hanh; Röseler, Waltraud; Sommer, Ralf J.

    2016-01-01

    Phenotypic plasticity has been suggested to act through developmental switches, but little is known about associated molecular mechanisms. In the nematode Pristionchus pacificus, the sulfatase eud-1 was identified as part of a developmental switch controlling mouth-form plasticity governing a predatory versus bacteriovorous mouth-form decision. Here we show that mutations in the conserved histone-acetyltransferase Ppa-lsy-12 and the methyl-binding-protein Ppa-mbd-2 mimic the eud-1 phenotype, resulting in the absence of one mouth-form. Mutations in both genes cause histone modification defects and reduced eud-1 expression. Surprisingly, Ppa-lsy-12 mutants also result in the down-regulation of an antisense-eud-1 RNA. eud-1 and antisense-eud-1 are co-expressed and further experiments suggest that antisense-eud-1 acts through eud-1 itself. Indeed, overexpression of the antisense-eud-1 RNA increases the eud-1-sensitive mouth-form and extends eud-1 expression. In contrast, this effect is absent in eud-1 mutants indicating that antisense-eud-1 positively regulates eud-1. Thus, chromatin remodelling and antisense-mediated up-regulation of eud-1 control feeding plasticity in Pristionchus. PMID:27487725

  20. Reduction of EGF receptor levels in human tumor cells transfected with an antisense RNA expression vector

    SciTech Connect

    Yamada, Hirotomo; Koizumi, Shinji; Kimura, Masami ); Shimizu, Nobuyoshi )

    1989-09-01

    An expression vector was constructed from part of pSV2neo with the 3{prime}-ClaI fragment of the epidermal growth factor (EGF) receptor cDNA inserted in an inverted orientation downstream from the human metallothionein (MT) IIa promoter. The human squamous carcinoma cell line NA, which overproduces EGF receptor, was transfected with this vector and selected for resistance to the neomycin derivative G418. One of the stable transfectants had a 90% reduction cell-surface EGF receptor in response to ZnSO{sub 4}. The nascent EGF receptor peptide was also decreased with concurrent induction of MT mRNA. These data suggest that the antisense transcript regulated by the MT promoter inhibits the expression of the endogenous EGF receptor genes. Although no transcripts from the antisense gene were detected, the results indicate that transfection with the antisense vector provides a technique by which to modulate the number of EGF receptors on the cell surface of squamous cell carcinomas.

  1. Regulation of the NPT gene by a naturally occurring antisense transcript.

    PubMed

    Werner, Andreas; Preston-Fayers, Keziah; Dehmelt, Leif; Nalbant, Perihan

    2002-01-01

    The epithelial Na/Pi cotransporter (NaPi-II) is instrumental in maintaining phosphate (Pi) homeostasis in vertebrates. Hormones and metabolic factors (PTH, Pi availability) that acutely influence renal Pi excretion have been demonstrated to target NaPi-II expression. Upon stimulation, newly synthesized transporter molecules become integrated into the brush-border membrane to increase the Vmax of Pi uptake; reduction of Pi reabsorption is achieved by endocytosis of NaPi-II followed by lysosomal degradation of the protein. The long-term regulation of the protein is less well studied. Only recently, regulatory elements for vitamin D3 and Pi have been identified in the promoter region of the npt gene. However, signaling pathways leading to the activation of these regulatory sequences need to be established. Other reports suggested messenger RNA stability to play a role in the medium range regulation of NaPi-II expression. Recent findings in our laboratory added to the complex picture of npt gene regulation. We have identified npt-related endogenous antisense transcripts from mouse, zebrafish, and winter flounder. The two fish transcripts have been cloned and characterized; the mouse homolog has only very recently been detected. The transcripts are devoid of an open reading frame and appear in different splice forms. The evolutionary conservation of bidirectional transcription of the npt gene implies a regulatory function for the antisense transcript. In order to test the functional consequences of bidirectional transcription, we coexpressed sense and the antisense transcripts from zebrafish in Xenopus oocytes. Pi transport activity was reduced as a result of the presence of antisense RNA. Re-extraction of the RNA from injected oocytes followed by Northern blot revealed that the coexpression had no significant effect on the stability of either transcript. We concluded that the antisense mRNA interfered with the translation of the transporter if coexpressed in the

  2. 3'-modified antisense oligodeoxyribonucleotides complementary to calmodulin mRNA alter behavioral responses in Paramecium.

    PubMed Central

    Hinrichsen, R D; Fraga, D; Reed, M W

    1992-01-01

    The calcium-binding protein calmodulin has been shown to modulate the Ca(2+)-dependent ion channels of Paramecium tetraurelia. Mutations in the calmodulin gene of Paramecium result in an altered pattern of behavioral responses. Antisense oligodeoxyribonucleotides (ODNs), complementary to calmodulin mRNA in Paramecium, were synthesized from a modified solid support that introduced a 3'-hydroxyhexyl phosphate. These 3'-modified ODNs were tested for their ability to alter the behavioral response of Paramecium. The microinjection of antisense ODNs temporarily reduced the backward swimming behavior of the cells in test solutions containing Na+. The injection of sense and random 3'-modified ODNs, or unmodified antisense ODNs, had no effect. The antisense ODN-induced effect was reversed by the injection of calmodulin protein. The pattern of response of the injected cells in various behavioral test solutions indicated that the calmodulin antisense ODNs reduce the Ca(2+)-dependent Na+ current. Antisense ODNs, complementary either to the 5' start site or to an internal sequence of the calmodulin mRNA, were similarly effective in altering behavior. These results show that antisense ODNs may be utilized in ciliated protozoa as a tool for reducing the expression of specific gene products. In addition, Paramecium represents a powerful model system with which to study and develop antisense ODN technology. PMID:1528867

  3. PU.1 antisense lncRNA against its mRNA translation promotes adipogenesis in porcine preadipocytes.

    PubMed

    Wei, N; Wang, Y; Xu, R-X; Wang, G-Q; Xiong, Y; Yu, T-Y; Yang, G-S; Pang, W-J

    2015-04-01

    Antisense long non-coding RNAs (AS lncRNAs) play important roles in refined regulation of animal gene expression. However, their functions and molecular mechanisms for domestic animal adipogenesis are largely unknown. Here, we found a novel AS lncRNA transcribed from the porcine PU.1 gene (also known as SPI1) by strand-specific RT-PCR. Results showed that PU.1 AS lncRNA was expressed and generally lower than the level of PU.1 mRNA in porcine subcutaneous adipose, heart, liver, spleen, lympha, skeletal muscle and kidney tissues. We further found that the levels of PU.1 mRNA and PU.1 protein were significantly lower in subcutaneous and intermuscular adipose than in mesenteric and greater omentum adipose, whereas the levels of PU.1 AS lncRNA showed no difference in porcine adipose tissues from four different parts of the body. During porcine adipogenesis, levels of PU.1 mRNA increased at day 2 and then gradually decreased. Meanwhile, PU.1 AS lncRNA exhibited an expression trend similar to PU.1 mRNA but sharply decreased after day 2. Interestingly, PU.1 protein level rose during differentiation. In addition, at day 6 after differentiation, knockdown of endogenous PU.1 promoted adipogenesis, whereas knockdown of endogenous PU.1 AS lncRNA had the opposite effect. Moreover, peroxisome proliferator-activated receptor gamma (PPARG) and fatty acid synthase (FASN) were significantly upregulated in the PU.1 shRNA treatment group (P < 0.05), whereas they were downregulated in the PU.1 AS shRNA treatment group (P < 0.05). Adipose triglyceride lipase [ATGL; also known as patatin-like phospholipase domain containing 2 (PNPLA2)] and hormone-sensitive lipase [HSL; also known as lipase, hormone-sensitive (LIPE)] contrasted with PPARG and FASN. Finally, the PU.1 mRNA/PU.1 AS lncRNA duplex was detected by an endogenous ribonuclease protection assay combined with RT-PCR. Based on the above results, we suggest that PU.1 AS lncRNA (vs. its mRNA translation) promotes adipogenesis through

  4. Extremely High Expression of Antisense RNA for Wilms' Tumor 1 in Active Osteoclasts: Suppression of Wilms' Tumor 1 Protein Expression during Osteoclastogenesis.

    PubMed

    Li, Yin-Ji; Kukita, Akiko; Kyumoto-Nakamura, Yukari; Kukita, Toshio

    2016-09-01

    Wilms' tumor 1 (WT1), a zinc-finger transcription regulator of the early growth response family, identified as the product of a tumor suppressor gene of Wilms' tumors, bears potential ability to induce macrophage differentiation in blood cell differentiation. Herein, we examined the involvement of WT1 in the regulation of osteoclastogenesis. We detected a high level of WT1 protein expression in osteoclast precursors; however, WT1 expression was markedly suppressed during osteoclastogenesis. We examined expression of WT1 transcripts in bone tissue by RNA in situ hybridization. We found a high level of antisense transcripts in osteoclasts actively resorbing bone in mandible of newborn rats. Expression of antisense WT1 RNA in mandible was also confirmed by Northern blot analysis and strand-specific RT-PCR. Overexpression of antisense WT1 RNA in RAW-D cells, an osteoclast precursor cell line, resulted in a marked enhancement of osteoclastogenesis, suggesting that antisense WT1 RNA functions to suppress expression of WT1 protein in osteoclastogenesis. High level expression of antisense WT1 RNA may contribute to commitment to osteoclastogenesis, and may allow osteoclasts to maintain or stabilize their differentiation state. PMID:27393793

  5. Episome-generated N-myc antisense RNA restricts the differentiation potential of primitive neuroectodermal cell lines.

    PubMed Central

    Whitesell, L; Rosolen, A; Neckers, L M

    1991-01-01

    Neuroectodermal tumors of childhood provide a unique opportunity to examine the role of genes potentially regulating neuronal growth and differentiation because many cell lines derived from these tumors are composed of at least two distinct morphologic cell types. These types display variant phenotypic characteristics and spontaneously interconvert, or transdifferentiate, in vitro. The factors that regulate transdifferentiation are unknown. Application of antisense approaches to the transdifferentiation process has allowed us to explore the precise role that N-myc may play in regulating developing systems. We now report construction of an episomally replicating expression vector designed to generate RNA antisense to part of the human N-myc gene. Such a vector is able to specifically inhibit N-myc expression in cell lines carrying both normal and amplified N-myc alleles. Inhibition of N-myc expression blocks transdifferentiation in these lines, with accumulation of cells of an intermediate phenotype. A concomitant decrease in growth rate but not loss of tumorigenicity was observed in the N-myc nonamplified cell line CHP-100. Vector-generated antisense RNA should allow identification of genes specifically regulated by the proto-oncogene N-myc. Images PMID:1996098

  6. The Drosophila micropia retrotransposon encodes a testis-specific antisense RNA complementary to reverse transcriptase.

    PubMed Central

    Lankenau, S; Corces, V G; Lankenau, D H

    1994-01-01

    The micropia transposable element of Drosophila hydei is a long terminal repeat-containing retrotransposon present in both the autosomes and the Y chromosome. micropia expression gives rise to a complex set of sense and antisense RNAs transcribed primarily during spermatogenesis. The most abundant sense RNAs constitute an assortment of heterogeneous high-molecular-weight transcripts expressed as constituents of the Y-chromosomal lampbrush loops of primary spermatocytes. In addition, micropia encodes a full-length RNA that extends between the two long terminal repeats of the element. The major 1.0-kb antisense RNA characterized is complementary to the reverse transcriptase and RNase H coding regions of micropia. It is expressed from a testis-specific promoter during the primary spermatocyte stages and is detectable until spermatid elongation stages. Sequence comparison of this promoter with the 5' region of other testis-specific genes allows the conception of a conserved sequence that is responsible for this pattern of expression. A 284-bp fragment containing this sequence is able to drive testis-specific expression of the Escherichia coli lacZ gene in Drosophila melanogaster. This sequence is conserved in the micropia elements present in other Drosophila species that also encode an antisense RNA. The evolutionary conservation of micropia antisense RNA expression and the sequences responsible for its testis-specific transcription suggests a role for this antisense RNA in the control of germ line expression of the full-length transcript or transposon-encoded proteins. Images PMID:7509447

  7. Regulation of Antisense Transcription by NuA4 Histone Acetyltransferase and Other Chromatin Regulatory Factors.

    PubMed

    Uprety, Bhawana; Kaja, Amala; Ferdoush, Jannatul; Sen, Rwik; Bhaumik, Sukesh R

    2016-01-01

    NuA4 histone lysine (K) acetyltransferase (KAT) promotes transcriptional initiation of TATA-binding protein (TBP)-associated factor (TAF)-dependent ribosomal protein genes. TAFs have also been recently found to enhance antisense transcription from the 3' end of the GAL10 coding sequence. However, it remains unknown whether, like sense transcription of the ribosomal protein genes, TAF-dependent antisense transcription of GAL10 also requires NuA4 KAT. Here, we show that NuA4 KAT associates with the GAL10 antisense transcription initiation site at the 3' end of the coding sequence. Such association of NuA4 KAT depends on the Reb1p-binding site that recruits Reb1p activator to the GAL10 antisense transcription initiation site. Targeted recruitment of NuA4 KAT to the GAL10 antisense transcription initiation site promotes GAL10 antisense transcription. Like NuA4 KAT, histone H3 K4/36 methyltransferases and histone H2B ubiquitin conjugase facilitate GAL10 antisense transcription, while the Swi/Snf and SAGA chromatin remodeling/modification factors are dispensable for antisense, but not sense, transcription of GAL10. Taken together, our results demonstrate for the first time the roles of NuA4 KAT and other chromatin regulatory factors in controlling antisense transcription, thus illuminating chromatin regulation of antisense transcription. PMID:26755557

  8. Interaction between the antisense and target RNAs involved in the regulation of IncB plasmid replication.

    PubMed Central

    Siemering, K R; Praszkier, J; Pittard, A J

    1993-01-01

    Physical analysis of RNA I, the small antisense RNA which regulates the replication of IncB miniplasmid pMU720, showed that it is a highly structured molecule containing an imperfectly paired stem closed by a 6-base hairpin loop. Mutational studies revealed that a 3-base sequence in the hairpin loop is critical to the interaction between RNA I and its complementary target in the RepA mRNA (RNA II). Furthermore, a 2-base interior loop in the upper stem was found to play an important role in facilitating effective binding between RNA I and RNA II. From these analyses, a model describing the molecular mechanism of binding between RNA I and RNA II is proposed. Images PMID:7684039

  9. Diversity of Antisense and Other Non-Coding RNAs in Archaea Revealed by Comparative Small RNA Sequencing in Four Pyrobaculum Species

    PubMed Central

    Bernick, David L.; Dennis, Patrick P.; Lui, Lauren M.; Lowe, Todd M.

    2012-01-01

    A great diversity of small, non-coding RNA (ncRNA) molecules with roles in gene regulation and RNA processing have been intensely studied in eukaryotic and bacterial model organisms, yet our knowledge of possible parallel roles for small RNAs (sRNA) in archaea is limited. We employed RNA-seq to identify novel sRNA across multiple species of the hyperthermophilic genus Pyrobaculum, known for unusual RNA gene characteristics. By comparing transcriptional data collected in parallel among four species, we were able to identify conserved RNA genes fitting into known and novel families. Among our findings, we highlight three novel cis-antisense sRNAs encoded opposite to key regulatory (ferric uptake regulator), metabolic (triose-phosphate isomerase), and core transcriptional apparatus genes (transcription factor B). We also found a large increase in the number of conserved C/D box sRNA genes over what had been previously recognized; many of these genes are encoded antisense to protein coding genes. The conserved opposition to orthologous genes across the Pyrobaculum genus suggests similarities to other cis-antisense regulatory systems. Furthermore, the genus-specific nature of these sRNAs indicates they are relatively recent, stable adaptations. PMID:22783241

  10. Down-regulation of protein kinase Ceta by antisense oligonucleotides sensitises A549 lung cancer cells to vincristine and paclitaxel.

    PubMed

    Sonnemann, Jürgen; Gekeler, Volker; Ahlbrecht, Katrin; Brischwein, Klaus; Liu, Chao; Bader, Peter; Müller, Cornelia; Niethammer, Dietrich; Beck, James F

    2004-06-25

    Previous studies point to protein kinase C (PKC) isozyme eta as a resistance factor in cancer cells. Therefore, we investigated whether down-regulation of PKCeta with second generation antisense oligonucleotides (ODNs) would sensitise A549 human lung carcinoma cells to cytostatics. The effects were compared to the outcome of Bcl-xL down-regulation. Upon treatment with antisense ODNs, PKCeta and Bcl-xL were both significantly reduced on mRNA and protein level. Down-regulation of either PKCeta or Bcl-xL in combination with vincristine or paclitaxel resulted in a significant increase in caspase-3 activity compared to that in the control oligonucleotide treated cells. In addition, PKCeta down-regulation augmented vincristine-induced dissipation of mitochondrial transmembrane potential. In conclusion, these results confirm that PKCeta might represent a considerable resistance factor and an interesting target to improve anticancer chemotherapy. PMID:15159020

  11. A new antisense tRNA construct for the genetic treatment of human immunodeficiency virus type 1 infection.

    PubMed Central

    Biasolo, M A; Radaelli, A; Del Pup, L; Franchin, E; De Giuli-Morghen, C; Palu, G

    1996-01-01

    Different strategies proposed in the literature to attempt gene therapy of AIDS are based mainly on the intracellular production of RNA and protein therapeutics. This report describes the construction and the anti-human immunodeficiency virus type 1 (HIV-1) activity of a new type of antisense tRNA directed against a nucleotide region in the first coding exon of HIV-1 tat (nucleotides 5924 to 5943; Los Alamos data bank) which is conserved among many HIV-1 clones. The anti-tat antisense sequence was inserted into a tRNA(Pro) backbone by replacement of the anticodon loop, without altering the tRNA canonic tetraloop structure. The antisense tRNA was able to interact effectively with its target in vitro. Jurkat cells that constitutively expressed the anti-tat tRNA following retroviral vector transduction exhibited significant resistance to HIV-1 de novo infection. Resistance seemed to correlate with the level of antisense expression. This is the first time that such a tRNA antisense strategy has been shown to be effective as a genetic treatment of HIV-1 infection in tissue culture. The construct design proposed in this report has some intrinsic advantages: the transcript is driven by a polymerase III promoter, the short length of the RNA minimizes effects of intramolecular base pairing that may impair target recognition, and the antisense RNA has the stability and intracellular fate of a native tRNA molecule. PMID:8642637

  12. Characteristics of Antisense Transcript Promoters and the Regulation of Their Activity

    PubMed Central

    Lin, Shudai; Zhang, Li; Luo, Wen; Zhang, Xiquan

    2015-01-01

    Recently, an increasing number of studies on natural antisense transcripts have been reported, especially regarding their classification, temporal and spatial expression patterns, regulatory functions and mechanisms. It is well established that natural antisense transcripts are produced from the strand opposite to the strand encoding a protein. Despite the pivotal roles of natural antisense transcripts in regulating the expression of target genes, the transcriptional mechanisms initiated by antisense promoters (ASPs) remain unknown. To date, nearly all of the studies conducted on this topic have focused on the ASP of a single gene of interest, whereas no study has systematically analyzed the locations of ASPs in the genome, ASP activity, or factors influencing this activity. This review focuses on elaborating on and summarizing the characteristics of ASPs to extend our knowledge about the mechanisms of antisense transcript initiation. PMID:26703594

  13. Disarmed anthrax toxin delivers antisense oligonucleotides and siRNA with high efficiency and low toxicity.

    PubMed

    Dyer, Paul D R; Shepherd, Thomas R; Gollings, Alexander S; Shorter, Susan A; Gorringe-Pattrick, Monique A M; Tang, Chun-Kit; Cattoz, Beatrice N; Baillie, Les; Griffiths, Peter C; Richardson, Simon C W

    2015-12-28

    Inefficient cytosolic delivery and vector toxicity contribute to the limited use of antisense oligonucleotides (ASOs) and siRNA as therapeutics. As anthrax toxin (Atx) accesses the cytosol, the purpose of this study was to evaluate the potential of disarmed Atx to deliver either ASOs or siRNA. We hypothesized that this delivery strategy would facilitate improved transfection efficiency while eliminating the toxicity seen for many vectors due to membrane destabilization. Atx complex formation with ASOs or siRNA was achieved via the in-frame fusion of either Saccharomyces cerevisiae GAL4 or Homo sapien sapien PKR (respectively) to a truncation of Atx lethal factor (LFn), which were used with Atx protective antigen (PA). Western immunoblotting confirmed the production of: LFN-GAL4, LFn-PKR and PA which were detected at ~45.9 kDa, ~37 kDa, and ~83 kDa respectively and small angle neutron scattering confirmed the ability of PA to form an annular structure with a radius of gyration of 7.0 ± 1.0 nm when placed in serum. In order to form a complex with LFn-GAL4, ASOs were engineered to contain a double-stranded region, and a cell free in vitro translation assay demonstrated that no loss of antisense activity above 30 pmol ASO was evident. The in vitro toxicity of both PA:LFn-GAL4:ASO and PA:LFn-PKR:siRNA complexes was low (IC50>100 μg/mL in HeLa and Vero cells) and subcellular fractionation in conjunction with microscopy confirmed the detection of LFn-GAL4 or LFn-PKR in the cytosol. Syntaxin5 (Synt5) was used as a model target gene to determine pharmacological activity. The PA:LFn-GAL4:ASO complexes had transfection efficiency approximately equivalent to Nucleofection® over a variety of ASO concentrations (24h post-transfection) and during a 72 h time course. In HeLa cells, at 200 pmol ASO (with PA:LFN-GAL4), 5.4 ± 2.0% Synt5 expression was evident relative to an untreated control after 24h. Using 200 pmol ASOs, Nucleofection® reduced Synt5 expression to 8.1 ± 2

  14. Antisense targeting of 3' end elements involved in DUX4 mRNA processing is an efficient therapeutic strategy for facioscapulohumeral dystrophy: a new gene-silencing approach.

    PubMed

    Marsollier, Anne-Charlotte; Ciszewski, Lukasz; Mariot, Virginie; Popplewell, Linda; Voit, Thomas; Dickson, George; Dumonceaux, Julie

    2016-04-15

    Defects in mRNA 3'end formation have been described to alter transcription termination, transport of the mRNA from the nucleus to the cytoplasm, stability of the mRNA and translation efficiency. Therefore, inhibition of polyadenylation may lead to gene silencing. Here, we choose facioscapulohumeral dystrophy (FSHD) as a model to determine whether or not targeting key 3' end elements involved in mRNA processing using antisense oligonucleotide drugs can be used as a strategy for gene silencing within a potentially therapeutic context. FSHD is a gain-of-function disease characterized by the aberrant expression of the Double homeobox 4 (DUX4) transcription factor leading to altered pathogenic deregulation of multiple genes in muscles. Here, we demonstrate that targeting either the mRNA polyadenylation signal and/or cleavage site is an efficient strategy to down-regulate DUX4 expression and to decrease the abnormally high-pathological expression of genes downstream of DUX4. We conclude that targeting key functional 3' end elements involved in pre-mRNA to mRNA maturation with antisense drugs can lead to efficient gene silencing and is thus a potentially effective therapeutic strategy for at least FSHD. Moreover, polyadenylation is a crucial step in the maturation of almost all eukaryotic mRNAs, and thus all mRNAs are virtually eligible for this antisense-mediated knockdown strategy. PMID:26787513

  15. Spt4 selectively regulates the expression of C9orf72 sense and antisense mutant transcripts.

    PubMed

    Kramer, Nicholas J; Carlomagno, Yari; Zhang, Yong-Jie; Almeida, Sandra; Cook, Casey N; Gendron, Tania F; Prudencio, Mercedes; Van Blitterswijk, Marka; Belzil, Veronique; Couthouis, Julien; Paul, Joseph West; Goodman, Lindsey D; Daughrity, Lillian; Chew, Jeannie; Garrett, Aliesha; Pregent, Luc; Jansen-West, Karen; Tabassian, Lilia J; Rademakers, Rosa; Boylan, Kevin; Graff-Radford, Neill R; Josephs, Keith A; Parisi, Joseph E; Knopman, David S; Petersen, Ronald C; Boeve, Bradley F; Deng, Ning; Feng, Yanan; Cheng, Tzu-Hao; Dickson, Dennis W; Cohen, Stanley N; Bonini, Nancy M; Link, Christopher D; Gao, Fen-Biao; Petrucelli, Leonard; Gitler, Aaron D

    2016-08-12

    An expanded hexanucleotide repeat in C9orf72 causes amyotrophic lateral sclerosis and frontotemporal dementia (c9FTD/ALS). Therapeutics are being developed to target RNAs containing the expanded repeat sequence (GGGGCC); however, this approach is complicated by the presence of antisense strand transcription of expanded GGCCCC repeats. We found that targeting the transcription elongation factor Spt4 selectively decreased production of both sense and antisense expanded transcripts, as well as their translated dipeptide repeat (DPR) products, and also mitigated degeneration in animal models. Knockdown of SUPT4H1, the human Spt4 ortholog, similarly decreased production of sense and antisense RNA foci, as well as DPR proteins, in patient cells. Therapeutic targeting of a single factor to eliminate c9FTD/ALS pathological features offers advantages over approaches that require targeting sense and antisense repeats separately. PMID:27516603

  16. Transcription of rat mitochondrial NADH-dehydrogenase subunits. Presence of antisense and precursor RNA species.

    PubMed

    Tullo, A; Tanzariello, F; D'Erchia, A M; Nardelli, M; Papeo, P A; Sbisà, E; Saccone, C

    1994-10-31

    We have characterized the transcriptional pattern of the rat mitochondrial ND6-containing region in vivo. We have identified a stable polyadenylated RNA species complementary for the full length of the ND6 mRNA. The analysis of the ND5 region has revealed the presence of an antisense RNA only at its 3' end. The presence of these stable antisense species complementary to structural genes is intriguing and suggests a possible regulatory function. The quantitative analyses have demonstrated that the H transcripts, both codogenic and non-codogenic, are more stable than the L transcripts. We have defined the 5' end of the ND6 mRNA at the level of the ATG downstream of the tRNA(Glu). The mapping of the ND1 5' end has demonstrated that GTG is the first codon of the mRNA. Our findings suggest that the post-transcriptional mechanisms involved in the expression of the mt genome are much more numerous and complex than those already described in the literature. PMID:7957896

  17. Cytoplasmic Control of Sense-Antisense mRNA Pairs.

    PubMed

    Sinturel, Flore; Navickas, Albertas; Wery, Maxime; Descrimes, Marc; Morillon, Antonin; Torchet, Claire; Benard, Lionel

    2015-09-22

    Transcriptome analyses have revealed that convergent gene transcription can produce many 3'-overlapping mRNAs in diverse organisms. Few studies have examined the fate of 3'-complementary mRNAs in double-stranded RNA-dependent nuclear phenomena, and nothing is known about the cytoplasmic destiny of 3'-overlapping messengers or their impact on gene expression. Here, we demonstrate that the complementary tails of 3'-overlapping mRNAs can interact in the cytoplasm and promote post-transcriptional regulatory events including no-go decay (NGD) in Saccharomyces cerevisiae. Genome-wide experiments confirm that these messenger-interacting mRNAs (mimRNAs) form RNA duplexes in wild-type cells and thus have potential roles in modulating the mRNA levels of their convergent gene pattern under different growth conditions. We show that the post-transcriptional fate of hundreds of mimRNAs is controlled by Xrn1, revealing the extent to which this conserved 5'-3' cytoplasmic exoribonuclease plays an unexpected but key role in the post-transcriptional control of convergent gene expression. PMID:26344770

  18. Expression of TGMV antisense RNA in transgenic tobacco inhibits replication of BCTV but not ACMV geminiviruses.

    PubMed

    Bejarano, E R; Lichtenstein, C P

    1994-01-01

    Transgenic tobacco plants expressing an antisense RNA targeted against tomato golden mosaic virus (TGMV) show reduced/no symptoms and viral DNA accumulation upon TGMV infection [5]. The targeted region includes the AL1 gene, encoding an essential viral replication protein. This DNA sequence is conserved in various other geminiviruses, suggesting they too might show inhibition of replication in these plants. We infected leaf material with African cassava mosaic virus (ACMV) and beet curly top virus (BTCV) and saw a 4-fold reduction of BCTV, but not ACMV, DNA accumulation, compared to controls. The equivalent regions of BCTV and ACMV show similar overall homology to the TGMV target (63% and 64% respectively), but within this, BCTV displays a 280 nucleotide region of high homology (82%). In contrast, for ACMV, the homology is more dispersed. This indicates that a critical stretch of good complementarity is needed to block expression of the target mRNA, that is effective even within along antisense transcript. These studies indicate the potential for developing a multifunctional antisense cassette. PMID:8111023

  19. Post-transcriptional gene silencing triggered by sense transgenes involves uncapped antisense RNA and differs from silencing intentionally triggered by antisense transgenes.

    PubMed

    Parent, Jean-Sébastien; Jauvion, Vincent; Bouché, Nicolas; Béclin, Christophe; Hachet, Mélanie; Zytnicki, Matthias; Vaucheret, Hervé

    2015-09-30

    Although post-transcriptional gene silencing (PTGS) has been studied for more than a decade, there is still a gap in our understanding of how de novo silencing is initiated against genetic elements that are not supposed to produce double-stranded (ds)RNA. Given the pervasive transcription occurring throughout eukaryote genomes, we tested the hypothesis that unintended transcription could produce antisense (as)RNA molecules that participate to the initiation of PTGS triggered by sense transgenes (S-PTGS). Our results reveal a higher level of asRNA in Arabidopsis thaliana lines that spontaneously trigger S-PTGS than in lines that do not. However, PTGS triggered by antisense transgenes (AS-PTGS) differs from S-PTGS. In particular, a hypomorphic ago1 mutation that suppresses S-PTGS prevents the degradation of asRNA but not sense RNA during AS-PTGS, suggesting a different treatment of coding and non-coding RNA by AGO1, likely because of AGO1 association to polysomes. Moreover, the intended asRNA produced during AS-PTGS is capped whereas the asRNA produced during S-PTGS derives from 3' maturation of a read-through transcript and is uncapped. Thus, we propose that uncapped asRNA corresponds to the aberrant RNA molecule that is converted to dsRNA by RNA-DEPENDENT RNA POLYMERASE 6 in siRNA-bodies to initiate S-PTGS, whereas capped asRNA must anneal with sense RNA to produce dsRNA that initiate AS-PTGS. PMID:26209135

  20. Post-transcriptional gene silencing triggered by sense transgenes involves uncapped antisense RNA and differs from silencing intentionally triggered by antisense transgenes

    PubMed Central

    Parent, Jean-Sébastien; Jauvion, Vincent; Bouché, Nicolas; Béclin, Christophe; Hachet, Mélanie; Zytnicki, Matthias; Vaucheret, Hervé

    2015-01-01

    Although post-transcriptional gene silencing (PTGS) has been studied for more than a decade, there is still a gap in our understanding of how de novo silencing is initiated against genetic elements that are not supposed to produce double-stranded (ds)RNA. Given the pervasive transcription occurring throughout eukaryote genomes, we tested the hypothesis that unintended transcription could produce antisense (as)RNA molecules that participate to the initiation of PTGS triggered by sense transgenes (S-PTGS). Our results reveal a higher level of asRNA in Arabidopsis thaliana lines that spontaneously trigger S-PTGS than in lines that do not. However, PTGS triggered by antisense transgenes (AS-PTGS) differs from S-PTGS. In particular, a hypomorphic ago1 mutation that suppresses S-PTGS prevents the degradation of asRNA but not sense RNA during AS-PTGS, suggesting a different treatment of coding and non-coding RNA by AGO1, likely because of AGO1 association to polysomes. Moreover, the intended asRNA produced during AS-PTGS is capped whereas the asRNA produced during S-PTGS derives from 3′ maturation of a read-through transcript and is uncapped. Thus, we propose that uncapped asRNA corresponds to the aberrant RNA molecule that is converted to dsRNA by RNA-DEPENDENT RNA POLYMERASE 6 in siRNA-bodies to initiate S-PTGS, whereas capped asRNA must anneal with sense RNA to produce dsRNA that initiate AS-PTGS. PMID:26209135

  1. Characterization of Natural Antisense Transcript, Sclerotia Development and Secondary Metabolism by Strand-Specific RNA Sequencing of Aspergillus flavus

    PubMed Central

    Yin, Chao; Guo, Yong; Lin, Ying; Pan, Li; Wang, Bin

    2014-01-01

    Aspergillus flavus has received much attention owing to its severe impact on agriculture and fermented products induced by aflatoxin. Sclerotia morphogenesis is an important process related to A. flavus reproduction and aflatoxin biosynthesis. In order to obtain an extensive transcriptome profile of A. flavus and provide a comprehensive understanding of these physiological processes, the isolated mRNA of A. flavus CA43 cultures was subjected to high-throughput strand-specific RNA sequencing (ssRNA-seq). Our ssRNA-seq data profiled widespread transcription across the A. flavus genome, quantified vast transcripts (73% of total genes) and annotated precise transcript structures, including untranslated regions, upstream open reading frames (ORFs), alternative splicing variants and novel transcripts. We propose natural antisense transcripts in A. flavus might regulate gene expression mainly on the post-transcriptional level. This regulation might be relevant to tune biological processes such as aflatoxin biosynthesis and sclerotia development. Gene Ontology annotation of differentially expressed genes between the mycelia and sclerotia cultures indicated sclerotia development was related closely to A. flavus reproduction. Additionally, we have established the transcriptional profile of aflatoxin biosynthesis and its regulation model. We identified potential genes linking sclerotia development and aflatoxin biosynthesis. These genes could be used as targets for controlled regulation of aflatoxigenic strains of A. flavus. PMID:24849659

  2. Endogenous siRNAs derived from a pair of natural cis-antisense transcripts regulate salt tolerance in Arabidopsis.

    PubMed

    Borsani, Omar; Zhu, Jianhua; Verslues, Paul E; Sunkar, Ramanjulu; Zhu, Jian-Kang

    2005-12-29

    In higher eukaryotes, miRNAs and siRNAs guide translational inhibition, mRNA cleavage, or chromatin regulation. We found that the antisense overlapping gene pair of Delta(1)-pyrroline-5-carboxylate dehydrogenase (P5CDH), a stress-related gene, and SRO5, a gene of unknown function, generates two types of siRNAs. When both transcripts are present, a 24-nt siRNA is formed by a biogenesis pathway dependent on DCL2, RDR6, SGS3, and NRPD1A. Initial cleavage of the P5CDH transcript guided by the 24-nt siRNA establishes a phase for the subsequent generation of 21-nt siRNAs by DCL1 and further cleavage of P5CDH transcripts. The expression of SRO5 is induced by salt, and this induction is required to initiate siRNA formation. Our data suggest that the P5CDH and SRO5 proteins are also functionally related, and that the P5CDH-SRO5 gene pair defines a mode of siRNA function and biogenesis that may be applied to other natural cis-antisense gene pairs in eukaryotic genomes. PMID:16377568

  3. Strand-specific RNA-seq reveals widespread occurrence of novel cis-natural antisense transcripts in rice

    PubMed Central

    2012-01-01

    Background Cis-natural antisense transcripts (cis-NATs) are RNAs transcribed from the antisense strand of a gene locus, and are complementary to the RNA transcribed from the sense strand. Common techniques including microarray approach and analysis of transcriptome databases are the major ways to globally identify cis-NATs in various eukaryotic organisms. Genome-wide in silico analysis has identified a large number of cis-NATs that may generate endogenous short interfering RNAs (nat-siRNAs), which participate in important biogenesis mechanisms for transcriptional and post-transcriptional regulation in rice. However, the transcriptomes are yet to be deeply sequenced to comprehensively investigate cis-NATs. Results We applied high-throughput strand-specific complementary DNA sequencing technology (ssRNA-seq) to deeply sequence mRNA for assessing sense and antisense transcripts that were derived under salt, drought and cold stresses, and normal conditions, in the model plant rice (Oryza sativa). Combined with RAP-DB genome annotation (the Rice Annotation Project Database build-5 data set), 76,013 transcripts corresponding to 45,844 unique gene loci were assembled, in which 4873 gene loci were newly identified. Of 3819 putative rice cis-NATs, 2292 were detected as expressed and giving rise to small RNAs from their overlapping regions through integrated analysis of ssRNA-seq data and small RNA data. Among them, 503 cis-NATs seemed to be associated with specific conditions. The deep sequence data from isolated epidermal cells of rice seedlings further showed that 54.0% of cis-NATs were expressed simultaneously in a population of homogenous cells. Nearly 9.7% of rice transcripts were involved in one-to-one or many-to-many cis-NATs formation. Furthermore, only 17.4-34.7% of 223 many-to-many cis-NAT groups were all expressed and generated nat-siRNAs, indicating that only some cis-NAT groups may be involved in complex regulatory networks. Conclusions Our study profiles an

  4. Regulating malonyl-CoA metabolism via synthetic antisense RNAs for enhanced biosynthesis of natural products.

    PubMed

    Yang, Yaping; Lin, Yuheng; Li, Lingyun; Linhardt, Robert J; Yan, Yajun

    2015-05-01

    Malonyl-CoA is the building block for fatty acid biosynthesis and also a precursor to various pharmaceutically and industrially valuable molecules, such as polyketides and biopolymers. However, intracellular malonyl-CoA is usually maintained at low levels, which poses great challenges to efficient microbial production of malonyl-CoA derived molecules. Inactivation of the malonyl-CoA consumption pathway to increase its intracellular availability is not applicable, since it is usually lethal to microorganisms. In this work, we employ synthetic antisense RNAs (asRNAs) to conditionally down-regulate fatty acid biosynthesis and achieve malonyl-CoA enrichment in Escherichia coli. The optimized asRNA constructs with a loop-stem structure exhibit high interference efficiency up to 80%, leading to a 4.5-fold increase in intracellular malonyl-CoA concentration when fabD gene expression is inhibited. Strikingly, this strategy allows the improved production of natural products 4-hydroxycoumarin, resveratrol, and naringenin by 2.53-, 1.70-, and 1.53-fold in E. coli, respectively. In addition, down-regulation of other fab genes including fabH, fabB, and fabF also leads to remarkable increases in 4-hydroxycoumarin production. This study demonstrates a novel strategy to enhance intracellular malonyl-CoA and indicates the effectiveness of asRNA as a powerful tool for use in metabolic engineering. PMID:25863265

  5. Analysis of the Mechanism of Action of the Antisense RNA That Controls the Replication of the repABC Plasmid p42d ▿ †

    PubMed Central

    Cervantes-Rivera, Ramón; Romero-López, Cristina; Berzal-Herranz, Alfredo; Cevallos, Miguel A.

    2010-01-01

    Replication and segregation of the Rhizobium etli symbiotic plasmid (pRetCFN42d) depend on the presence of a repABC operon, which carries all the plasmid-encoded elements required for these functions. All repABC operons share three protein-encoding genes (repA, repB, and repC), an antisense RNA (ctRNA) coding gene, and at least one centromere-like region (parS). The products of repA and repB, in conjunction with the parS region, make up the segregation system, and they negatively regulate operon transcription. The last gene of the operon, repC, encodes the initiator protein. The ctRNA is a negative posttranscriptional regulator of repC. In this work, we analyzed the secondary structures of the ctRNA and its target and mapped the motifs involved in the complex formed between them. Essential residues for the effective interaction localize at the unpaired 5′ end of the antisense molecule and the loop of the target mRNA. In light of our results, we propose a model explaining the mechanism of action of this ctRNA in the regulation of plasmid replication in R. etli. PMID:20435728

  6. Characterization of a Novel Antisense RNA in the Major Pilin Locus of Neisseria meningitidis Influencing Antigenic Variation

    PubMed Central

    Tan, Felicia Y. Y.; Wörmann, Mirka E.; Tang, Christoph M.

    2015-01-01

    ABSTRACT Expression of type four pili (Tfp) is essential for virulence in Neisseria meningitidis. Pili mediate adhesion, bacterial aggregation, and DNA uptake. In N. meningitidis, the major pilin subunit is encoded by the pilE gene. In some strains, PilE is subject to phase and antigenic variation, which can alter Tfp properties and together offer a possible mechanism of immune escape. Pilin expression and antigenic variation can be modulated in response to environmental cues; however, the precise mechanisms of such regulation remain unclear. We identified a promoter in the pilE locus, 3′ of the pilE coding sequence, on the antisense (AS) strand which is conserved in meningococci. We show that this promoter directs transcription of an AS RNA that is expressed during specific growth phases and in response to salt stress. Furthermore, we demonstrate that the transcript encompasses sequences complementary to the entire pilE coding sequence and 5′ untranslated region. AS RNAs can regulate the gene on the sense strand by altering transcript stability or translation. However, by using Northern blotting, quantitative reverse transcription-PCR (RT-PCR), and Western blotting, we found no significant AS RNA-dependent changes in pilE transcript or protein level. Instead, our data indicate that the AS RNA influences pilin antigenic variation. This work provides further insights into the complex regulation of pilin expression and variation in pathogenic Neisseria. IMPORTANCE Pathogenic Neisseria spp. express type four pili (Tfp) which are important for adhesion, aggregation and transformation. Some strains of N. meningitidis are able to vary the sequence of the major subunit (PilE) of the Tfp. The mechanisms underlying this variation are not fully defined, but the process requires several noncoding elements that are found adjacent to the pilE gene. In this work, we identified a cis-encoded RNA antisense to pilE in N. meningitidis. By using Northern blotting and RT

  7. A multifactor regulatory circuit involving H-NS, VirF and an antisense RNA modulates transcription of the virulence gene icsA of Shigella flexneri

    PubMed Central

    Tran, Chi Nhan; Giangrossi, Mara; Prosseda, Gianni; Brandi, Anna; Di Martino, Maria Letizia; Colonna, Bianca; Falconi, Maurizio

    2011-01-01

    The icsA gene of Shigella encodes a structural protein involved in colonization of the intestinal mucosa by bacteria. This gene is expressed upon invasion of the host and is controlled by a complex regulatory circuit involving the nucleoid protein H-NS, the AraC-like transcriptional activator VirF, and a 450 nt antisense RNA (RnaG) acting as transcriptional attenuator. We investigated on the interplay of these factors at the molecular level. DNase I footprints reveal that both H-NS and VirF bind to a region including the icsA and RnaG promoters. H-NS is shown to repress icsA transcription at 30°C but not at 37°C, suggesting a significant involvement of this protein in the temperature-regulated expression of icsA. We also demonstrate that VirF directly stimulates icsA transcription and is able to alleviate H-NS repression in vitro. According to these results, icsA expression is derepressed in hns- background and overexpressed when VirF is provided in trans. Moreover, we find that RnaG-mediated transcription attenuation depends on 80 nt at its 5′-end, a stretch carrying the antisense region. Bases engaged in the initial contact leading to sense–antisense pairing have been identified using synthetic RNA and DNA oligonucleotides designed to rebuild and mutagenize the two stem–loop motifs of the antisense region. PMID:21724612

  8. Defining a role for Hfq in Gram-positive bacteria: evidence for Hfq-dependent antisense regulation in Listeria monocytogenes

    PubMed Central

    Nielsen, Jesper Sejrup; Lei, Lisbeth Kristensen; Ebersbach, Tine; Olsen, Anders Steno; Klitgaard, Janne Kudsk; Valentin-Hansen, Poul; Kallipolitis, Birgitte Haahr

    2010-01-01

    Small trans-encoded RNAs (sRNAs) modulate the translation and decay of mRNAs in bacteria. In Gram-negative species, antisense regulation by trans-encoded sRNAs relies on the Sm-like protein Hfq. In contrast to this, Hfq is dispensable for sRNA-mediated riboregulation in the Gram-positive species studied thus far. Here, we provide evidence for Hfq-dependent translational repression in the Gram-positive human pathogen Listeria monocytogenes, which is known to encode at least 50 sRNAs. We show that the Hfq-binding sRNA LhrA controls the translation and degradation of its target mRNA by an antisense mechanism, and that Hfq facilitates the binding of LhrA to its target. The work presented here provides the first experimental evidence for Hfq-dependent riboregulation in a Gram-positive bacterium. Our findings indicate that modulation of translation by trans-encoded sRNAs may occur by both Hfq-dependent and -independent mechanisms, thus adding another layer of complexity to sRNA-mediated riboregulation in Gram-positive species. PMID:19942685

  9. Bimodal expression of PHO84 is modulated by early termination of antisense transcription

    PubMed Central

    Castelnuovo, Manuele; Rahman, Samir; Guffanti, Elisa; Infantino, Valentina; Stutz, Françoise; Zenklusen, Daniel

    2016-01-01

    Many S. cerevisiae genes encode antisense transcripts some of which are unstable and degraded by the exosome component Rrp6. Loss of Rrp6 results in the accumulation of long PHO84 antisense RNAs and repression of sense transcription through PHO84 promoter deacetylation. We used single molecule resolution fluorescent in situ hybridization (smFISH) to investigate antisense-mediated transcription regulation. We show that PHO84 antisense RNA acts as a bimodal switch, where continuous low frequency antisense transcription represses sense expression within individual cells. Surprisingly, antisense RNAs do not accumulate at the PHO84 gene but are exported to the cytoplasm. Furthermore, loss of Rrp6, rather than stabilizing PHO84 antisense RNA, promotes antisense elongation by reducing its early transcription termination by Nrd1-Nab3-Sen1. These observations suggest that PHO84 silencing results from constant low frequency antisense transcription through the promoter rather than its static accumulation at the repressed gene. PMID:23770821

  10. Quantitative Proteomics Analysis Reveals Novel Insights into Mechanisms of Action of Long Noncoding RNA Hox Transcript Antisense Intergenic RNA (HOTAIR) in HeLa Cells*

    PubMed Central

    Zheng, Peng; Xiong, Qian; Wu, Ying; Chen, Ying; Chen, Zhuo; Fleming, Joy; Gao, Ding; Bi, Lijun; Ge, Feng

    2015-01-01

    Long noncoding RNAs (lncRNAs), which have emerged in recent years as a new and crucial layer of gene regulators, regulate various biological processes such as carcinogenesis and metastasis. HOTAIR (Hox transcript antisense intergenic RNA), a lncRNA overexpressed in most human cancers, has been shown to be an oncogenic lncRNA. Here, we explored the role of HOTAIR in HeLa cells and searched for proteins regulated by HOTAIR. To understand the mechanism of action of HOTAIR from a systems perspective, we employed a quantitative proteomic strategy to systematically identify potential targets of HOTAIR. The expression of 170 proteins was significantly dys-regulated after inhibition of HOTAIR, implying that they could be potential targets of HOTAIR. Analysis of this data at the systems level revealed major changes in proteins involved in diverse cellular components, including the cytoskeleton and the respiratory chain. Further functional studies on vimentin (VIM), a key protein involved in the cytoskeleton, revealed that HOTAIR exerts its effects on migration and invasion of HeLa cells, at least in part, through the regulation of VIM expression. Inhibition of HOTAIR leads to mitochondrial dysfunction and ultrastructural alterations, suggesting a novel role of HOTAIR in maintaining mitochondrial function in cancer cells. Our results provide novel insights into the mechanisms underlying the function of HOTAIR in cancer cells. We expect that the methods used in this study will become an integral part of functional studies of lncRNAs. PMID:25762744

  11. RNA cleavage products generated by antisense oligonucleotides and siRNAs are processed by the RNA surveillance machinery

    PubMed Central

    Lima, Walt F.; De Hoyos, Cheryl L.; Liang, Xue-hai; Crooke, Stanley T.

    2016-01-01

    DNA-based antisense oligonucleotides (ASOs) elicit cleavage of the targeted RNA by the endoribonuclease RNase H1, whereas siRNAs mediate cleavage through the RNAi pathway. To determine the fates of the cleaved RNA in cells, we lowered the levels of the factors involved in RNA surveillance prior to treating cells with ASOs or siRNA and analyzed cleavage products by RACE. The cytoplasmic 5′ to 3′ exoribonuclease XRN1 was responsible for the degradation of the downstream cleavage products generated by ASOs or siRNA targeting mRNAs. In contrast, downstream cleavage products generated by ASOs targeting nuclear long non-coding RNA Malat 1 and pre-mRNA were degraded by nuclear XRN2. The downstream cleavage products did not appear to be degraded in the 3′ to 5′ direction as the majority of these products contained intact poly(A) tails and were bound by the poly(A) binding protein. The upstream cleavage products of Malat1 were degraded in the 3′ to 5′ direction by the exosome complex containing the nuclear exoribonuclease Dis3. The exosome complex containing Dis3 or cytoplasmic Dis3L1 degraded mRNA upstream cleavage products, which were not bound by the 5′-cap binding complex and, consequently, were susceptible to degradation in the 5′ to 3′ direction by the XRN exoribonucleases. PMID:26843429

  12. RNA cleavage products generated by antisense oligonucleotides and siRNAs are processed by the RNA surveillance machinery.

    PubMed

    Lima, Walt F; De Hoyos, Cheryl L; Liang, Xue-Hai; Crooke, Stanley T

    2016-04-20

    DNA-based antisense oligonucleotides (ASOs) elicit cleavage of the targeted RNA by the endoribonuclease RNase H1, whereas siRNAs mediate cleavage through the RNAi pathway. To determine the fates of the cleaved RNA in cells, we lowered the levels of the factors involved in RNA surveillance prior to treating cells with ASOs or siRNA and analyzed cleavage products by RACE. The cytoplasmic 5' to 3' exoribonuclease XRN1 was responsible for the degradation of the downstream cleavage products generated by ASOs or siRNA targeting mRNAs. In contrast, downstream cleavage products generated by ASOs targeting nuclear long non-coding RNA Malat 1 and pre-mRNA were degraded by nuclear XRN2. The downstream cleavage products did not appear to be degraded in the 3' to 5' direction as the majority of these products contained intact poly(A) tails and were bound by the poly(A) binding protein. The upstream cleavage products of Malat1 were degraded in the 3' to 5' direction by the exosome complex containing the nuclear exoribonuclease Dis3. The exosome complex containing Dis3 or cytoplasmic Dis3L1 degraded mRNA upstream cleavage products, which were not bound by the 5'-cap binding complex and, consequently, were susceptible to degradation in the 5' to 3' direction by the XRN exoribonucleases. PMID:26843429

  13. Antisense long noncoding RNAs regulate var gene activation in the malaria parasite Plasmodium falciparum

    PubMed Central

    Amit-Avraham, Inbar; Pozner, Guy; Eshar, Shiri; Fastman, Yair; Kolevzon, Netanel; Yavin, Eylon; Dzikowski, Ron

    2015-01-01

    The virulence of Plasmodium falciparum, the causative agent of the deadliest form of human malaria, is attributed to its ability to evade human immunity through antigenic variation. These parasites alternate between expression of variable antigens, encoded by members of a multicopy gene family named var. Immune evasion through antigenic variation depends on tight regulation of var gene expression, ensuring that only a single var gene is expressed at a time while the rest of the family is maintained transcriptionally silent. Understanding how a single gene is chosen for activation is critical for understanding mutually exclusive expression but remains a mystery. Here, we show that antisense long noncoding RNAs (lncRNAs) initiating from var introns are associated with the single active var gene at the time in the cell cycle when the single var upstream promoter is active. We demonstrate that these antisense transcripts are incorporated into chromatin, and that expression of these antisense lncRNAs in trans triggers activation of a silent var gene in a sequence- and dose-dependent manner. On the other hand, interference with these lncRNAs using complement peptide nucleic acid molecules down-regulated the active var gene, erased the epigenetic memory, and induced expression switching. Altogether, our data provide evidence that these antisense lncRNAs play a key role in regulating var gene activation and mutually exclusive expression. PMID:25691743

  14. Ustilago maydis natural antisense transcript expression alters mRNA stability and pathogenesis

    PubMed Central

    Donaldson, Michael E; Saville, Barry J

    2013-01-01

    Ustilago maydis infection of Zea mays leads to the production of thick-walled diploid teliospores that are the dispersal agent for this pathogen. Transcriptome analyses of this model biotrophic basidiomycete fungus identified natural antisense transcripts (NATs) complementary to 247 open reading frames. The U. maydis NAT cDNAs were fully sequenced and annotated. Strand-specific RT-PCR screens confirmed expression and identified NATs preferentially expressed in the teliospore. Targeted screens revealed four U. maydis NATs that are conserved in a related fungus. Expression of NATs in haploid cells, where they are not naturally occurring, resulted in increased steady-state levels of some complementary mRNAs. The expression of one NAT, as-um02151, in haploid cells resulted in a twofold increase in complementary mRNA levels, the formation of sense–antisense double-stranded RNAs, and unchanged Um02151 protein levels. This led to a model for NAT function in the maintenance and expression of stored teliospore mRNAs. In testing this model by deletion of the regulatory region, it was determined that alteration in NAT expression resulted in decreased pathogenesis in both cob and seedling infections. This annotation and functional analysis supports multiple roles for U. maydis NATs in controlling gene expression and influencing pathogenesis. PMID:23650872

  15. Expression analysis of the long non-coding RNA antisense to Uchl1 (AS Uchl1) during dopaminergic cells' differentiation in vitro and in neurochemical models of Parkinson's disease

    PubMed Central

    Carrieri, Claudia; Forrest, Alistair R. R.; Santoro, Claudio; Persichetti, Francesca; Carninci, Piero; Zucchelli, Silvia; Gustincich, Stefano

    2015-01-01

    Antisense (AS) transcripts are RNA molecules that are transcribed from the opposite strand to sense (S) genes forming S/AS pairs. The most prominent configuration is when a lncRNA is antisense to a protein coding gene. Increasing evidences prove that antisense transcription may control sense gene expression acting at distinct regulatory levels. However, its contribution to brain function and neurodegenerative diseases remains unclear. We have recently identified AS Uchl1 as an antisense to the mouse Ubiquitin carboxy-terminal hydrolase L1 (Uchl1) gene (AS Uchl1), the synthenic locus of UCHL1/PARK5. This is mutated in rare cases of early-onset familial Parkinson's Disease (PD) and loss of UCHL1 activity has been reported in many neurodegenerative diseases. Importantly, manipulation of UchL1 expression has been proposed as tool for therapeutic intervention. AS Uchl1 induces UchL1 expression by increasing its translation. It is the representative member of SINEUPs (SINEB2 sequence to UP-regulate translation), a new functional class of natural antisense lncRNAs that activate translation of their sense genes. Here we take advantage of FANTOM5 dataset to identify the transcription start sites associated to S/AS pair at Uchl1 locus. We show that AS Uchl1 expression is under the regulation of Nurr1, a major transcription factor involved in dopaminergic cells' differentiation and maintenance. Furthermore, AS Uch1 RNA levels are strongly down-regulated in neurochemical models of PD in vitro and in vivo. This work positions AS Uchl1 RNA as a component of Nurr1-dependent gene network and target of cellular stress extending our understanding on the role of antisense transcription in the brain. PMID:25883552

  16. Nanotechnologies and controlled release systems for the delivery of antisense oligonucleotides and small interfering RNA

    PubMed Central

    Fattal, Elias; Barratt, Gillian

    2009-01-01

    Antisense oligonucleotides and small interfering RNA have enormous potential for the treatment of a number of diseases, including cancer. However, several impediments to their widespread use as drugs still have to be overcome: in particular their lack of stability in physiological fluids and their poor penetration into cells. Association with or encapsulation within nano-and microsized drug delivery systems could help to solve these problems. In this review, we describe the progress that has been made using delivery systems composed of natural or synthetic polymers in the form of complexes, nanoparticles or microparticles. This article is part of a themed section on Vector Design and Drug Delivery. For a list of all articles in this section see the end of this paper, or visit: http://www3.interscience.wiley.com/journal/121548564/issueyear?year=200 PMID:19366348

  17. The Role of Structural Elements of the 5'-Terminal Region of p53 mRNA in Translation under Stress Conditions Assayed by the Antisense Oligonucleotide Approach

    PubMed Central

    Swiatkowska, Agata; Zydowicz, Paulina; Gorska, Agnieszka; Suchacka, Julia; Dutkiewicz, Mariola; Ciesiołka, Jerzy

    2015-01-01

    The p53 protein is one of the major factors responsible for cell cycle regulation and stress response. In the 5’-terminal region of p53 mRNA, an IRES element has been found which takes part in the translational regulation of p53 expression. Two characteristic hairpin motifs are present in this mRNA region: G56-C169, with the first AUG codon, and U180-A218, which interacts with the Hdm2 protein (human homolog of mouse double minute 2 protein). 2′-OMe modified antisense oligomers hybridizing to the 5'-terminal region of p53 mRNA were applied to assess the role of these structural elements in translation initiation under conditions of cellular stress. Structural changes in the RNA target occurring upon oligomers’ binding were monitored by the Pb2+-induced cleavage method. The impact of antisense oligomers on the synthesis of two proteins, the full-length p53 and its isoform Δ40p53, was analysed in HT-29, MCF-7 and HepG2 cells, under normal conditions and under stress, as well as in vitro conditions. The results revealed that the hairpin U180-A218 and adjacent single-stranded region A219-A228 were predominantly responsible for high efficacy of IRES-mediated translation in the presence of stress factors. These motifs play a role of cis-acting elements which are able to modulate IRES activity, likely via interactions with protein factors. PMID:26513723

  18. A modular strategy for engineering orthogonal chimeric RNA transcription regulators

    PubMed Central

    Takahashi, Melissa K.; Lucks, Julius B.

    2013-01-01

    Antisense RNA transcription attenuators are a key component of the synthetic biology toolbox, with their ability to serve as building blocks for both signal integration logic circuits and transcriptional cascades. However, a central challenge to building more sophisticated RNA genetic circuitry is creating larger families of orthogonal attenuators that function independently of each other. Here, we overcome this challenge by developing a modular strategy to create chimeric fusions between the engineered transcriptional attenuator from plasmid pT181 and natural antisense RNA translational regulators. Using in vivo gene expression assays in Escherichia coli, we demonstrate our ability to create chimeric attenuators by fusing sequences from five different translational regulators. Mutagenesis of these functional attenuators allowed us to create a total of 11 new chimeric attenutaors. A comprehensive orthogonality test of these culminated in a 7 × 7 matrix of mutually orthogonal regulators. A comparison between all chimeras tested led to design principles that will facilitate further engineering of orthogonal RNA transcription regulators, and may help elucidate general principles of non-coding RNA regulation. We anticipate that our strategy will accelerate the development of even larger families of orthogonal RNA transcription regulators, and thus create breakthroughs in our ability to construct increasingly sophisticated RNA genetic circuitry. PMID:23761434

  19. Regulation of Nav1.7: A Conserved SCN9A Natural Antisense Transcript Expressed in Dorsal Root Ganglia

    PubMed Central

    Koenig, Jennifer; Werdehausen, Robert; Linley, John E.; Habib, Abdella M.; Vernon, Jeffrey; Lolignier, Stephane; Eijkelkamp, Niels; Zhao, Jing; Okorokov, Andrei L.; Woods, C. Geoffrey; Wood, John N.; Cox, James J.

    2015-01-01

    The Nav1.7 voltage-gated sodium channel, encoded by SCN9A, is critical for human pain perception yet the transcriptional and post-transcriptional mechanisms that regulate this gene are still incompletely understood. Here, we describe a novel natural antisense transcript (NAT) for SCN9A that is conserved in humans and mice. The NAT has a similar tissue expression pattern to the sense gene and is alternatively spliced within dorsal root ganglia. The human and mouse NATs exist in cis with the sense gene in a tail-to-tail orientation and both share sequences that are complementary to the terminal exon of SCN9A/Scn9a. Overexpression analyses of the human NAT in human embryonic kidney (HEK293A) and human neuroblastoma (SH-SY5Y) cell lines show that it can function to downregulate Nav1.7 mRNA, protein levels and currents. The NAT may play an important role in regulating human pain thresholds and is a potential candidate gene for individuals with chronic pain disorders that map to the SCN9A locus, such as Inherited Primary Erythromelalgia, Paroxysmal Extreme Pain Disorder and Painful Small Fibre Neuropathy, but who do not contain mutations in the sense gene. Our results strongly suggest the SCN9A NAT as a prime candidate for new therapies based upon augmentation of existing antisense RNAs in the treatment of chronic pain conditions in man. PMID:26035178

  20. Analysis of the mechanism of protection in transgenic plants expressing the potato virus X coat protein or its antisense RNA.

    PubMed

    Hemenway, C; Fang, R X; Kaniewski, W K; Chua, N H; Tumer, N E

    1988-05-01

    Transgenic tobacco plants engineered to express either the potato virus X (PVX) coat protein (CP+) or the antisense coat protein transcript (CP-antisense) were protected from infection by PVX, as indicated by reduced lesion numbers on inoculated leaves, delay or absence of systemic symptom development and reduction in virus accumulation in both inoculated and systemic leaves. The extent of protection observed in CP+ plants primarily depended upon the level of expression of the coat protein. Plants expressing antisense RNA were protected only at low inoculum concentrations. The extent of this protection was even lower than that observed in plants expressing low levels of CP. In contrast to previous reports for plants expressing tobacco mosaic virus or alfalfa mosaic virus CP, inoculation of plants expressing high levels of PVX CP with PVX RNA did not overcome the protection. Specifically, lesion numbers on inoculated leaves and PVX levels on inoculated and systemtic leaves of the CP+ plants were reduced to a similar extent in both virus and RNA inoculated plants. Although these results do not rule out that CP-mediated protection involves inhibition of uncoating of the challenge virus, they suggest that PVX CP (or its RNA) can moderate early events in RNA infection by a different mechanism. PMID:16453840

  1. Biodegradable polymer nanocarriers for therapeutic antisense microRNA delivery in living animals

    NASA Astrophysics Data System (ADS)

    Paulmurugan, Ramasamy; Sekar, Narayana M.; Sekar, Thillai V.

    2012-03-01

    MicroRNAs are endogenous regulators of gene expression, deregulated in several cellular diseases including cancer. Altering the cellular microenvironment by modulating the microRNAs functions can regulate different genes involved in major cellular processes, and this approach is now being investigated as a promising new generation of molecularly targeted anti-cancer therapies. AntagomiRs (Antisense-miRNAs) are a novel class of chemically modified stable oligonucleotides used for blocking the functions of endogenous microRNAs, which are overexpressed. A key challenge in achieving effective microRNAbased therapeutics lies in the development of an efficient delivery system capable of specifically delivering antisense oligonucleotides and target cancer cells in living animals. We are now developing an effective delivery system designed to selectively deliver antagomiR- 21 and antagomiR-10b to triple negative breast cancer cells, and to revert tumor cell metastasis and invasiveness. The FDA-approved biodegradable PLGA-nanoparticles were selected as a carrier for antagomiRs delivery. Chemically modified antagomiRs (antagomiR-21 and antagomiR-10b) were co-encapsulated in PEGylated-PLGA-nanoparticles by using the double-emulsification (W/O/W) solvent evaporation method, and the resulting average particle size of 150-200nm was used for different in vitro and in vivo experiments. The antagomiR encapsulated PLGA-nanoparticles were evaluated for their in vitro antagomiRs delivery, intracellular release profile, and antagomiRs functional effects, by measuring the endogenous cellular targets, and the cell growth and metastasis. The xenografts of tumor cells in living mice were used for evaluating the anti-metastatic and anti-invasive properties of cells. The results showed that the use of PLGA for antagomiR delivery is not only efficient in crossing cell membrane, but can also maintain functional intracellular antagomiRs level for a extended period of time and achieve

  2. Tetracycline-inducible shRNA targeting antisense long non-coding RNA HIF1A-AS2 represses the malignant phenotypes of bladder cancer.

    PubMed

    Chen, Mingwei; Zhuang, Chengle; Liu, Yuchen; Li, Jianfa; Dai, Fen; Xia, Ming; Zhan, Yonghao; Lin, Junhao; Chen, Zhicong; He, Anbang; Xu, Wen; Zhao, Guoping; Guo, Yinglu; Cai, Zhiming; Huang, Weiren

    2016-06-28

    Various studies have indicated that long non-coding RNAs (lncRNAs) play vital roles in the cancer development and progression. LncRNA hypoxia inducible factor 1alpha antisense RNA-2 (HIF1A-AS2) is upregulated in gastric carcinomas and knockdown of HIF1A-AS2 expression by siRNA could inhibit cell proliferation in vitro and tumorigenesis in vivo. Inspired by these observations, we hypothesized that HIF1A-AS2 possibly plays the analogous roles in bladder cancer. In our study, we first reported that HIF1A-AS2 was up-regulated in bladder cancer tissues and cells, and HIF1A-AS2 expression level in bladder cancer tissues is positively associated with advanced clinical pathologic grade and TNM phase. Cell proliferation inhibition, cell migration suppression and apoptosis induction were observed by silencing HIF1A-AS2 in bladder cancer T24 and 5637 cells. Overexpression of HIF1A-AS2 in SV-HUC-1 cells could promote cell proliferation, cell migration and anti-apoptosis. Besides, we utilized the emerging technology of medical synthetic biology to design tetracycline-inducible small hairpin RNA (shRNA) vector which specifically silenced HIF1A-AS2 in a dosage-dependent manner to inhibit the progression of human bladder cancer. In conclusion, our data suggested that HIF1A-AS2 plays oncogenic roles and can be used as a therapeutic target for treating human bladder cancer. Synthetic "tetracycline-on" switch system that quantitatively controlled the expression of HIF1A-AS2 in bladder cancer can inhibit the progression of bladder cancer cells in a dosage-dependent manner. Our findings provide new insights into the role of the lncRNA HIF1A-AS2 in the bladder cancer. PMID:27018306

  3. Small antisense oligonucleotides against G-quadruplexes: specific mRNA translational switches

    PubMed Central

    Rouleau, Samuel G.; Beaudoin, Jean-Denis; Bisaillon, Martin; Perreault, Jean-Pierre

    2015-01-01

    G-quadruplexes (G4) are intricate RNA structures found throughout the transcriptome. Because they are associated with a variety of biological cellular mechanisms, these fascinating structural motifs are seen as potential therapeutic targets against many diseases. While screening of chemical compounds specific to G4 motifs has yielded interesting results, no single compound successfully discriminates between G4 motifs based on nucleotide sequences alone. This level of specificity is best attained using antisense oligonucleotides (ASO). Indeed, oligonucleotide-based strategies are already used to modulate DNA G4 folding in vitro. Here, we report that, in human cells, the use of short ASO to promote and inhibit RNA G4 folding affects the translation of specific mRNAs, including one from the 5′UTR of the H2AFY gene, a histone variant associated with cellular differentiation and cancer. These results suggest that the relatively high specificity of ASO-based strategies holds significant potential for applications aimed at modulating G4-motif folding. PMID:25510493

  4. Regulation of S-like ribonuclease levels in Arabidopsis. Antisense inhibition of RNS1 or RNS2 elevates anthocyanin accumulation

    SciTech Connect

    Bariola, P.A.; MacIntosh, G.C.; Green, P.J.

    1999-01-01

    The S-like ribonucleases (RNases) RNS1 and RNS2 of Arabidopsis are members of the widespread T{sub 2} ribonuclease family, whose members also include the S-RNases, involved in gametophytic self-incompatibility in plants. Both RNS1 and RNS2 mRNAs have been shown previously to be induced by inorganic phosphate (Pi) starvation. In this study the authors examined this regulation at the protein level and determined the effects of diminishing RNS1 and RNS2 expression using antisense techniques. The Pi-starvation control of RNS1 and RNS2 was confirmed using antibodies specific for each protein. These specific antibodies also demonstrated that RNS1 is secreted, whereas RNS2 is intracellular. By introducing antisense constructs, mRNA accumulation was inhibited by up to 90% for RNS1 and up to 65% for NS2. These plants contained abnormally high levels of anthocyanins, the production of which is often associated with several forms of stress, including Pi starvation. This effect demonstrates that diminishing the amounts of either RNS1 or RNS2 leads to effects that cannot be compensated for by the actions of other RNases, even though Arabidopsis contains a large number of different RNase activities. These results, together with the differential localization of the proteins, imply that RNS1 and RNS2 have distinct functions in the plant.

  5. Effects of variations in length of hammerhead ribozyme antisense arms upon the cleavage of longer RNA substrates.

    PubMed Central

    Sioud, M

    1997-01-01

    The efficacy of intracellular binding of hammerhead ribozyme to its cleavage site in target RNA is a major requirement for its use as a therapeutic agent. Such efficacy can be influenced by several factors, such as the length of the ribozyme antisense arms and mRNA secondary structures. Analysis of various IL-2 hammerhead ribozymes having different antisense arms but directed to the same site predicts that the hammerhead ribozyme target site is present within a double-stranded region that is flanked by single-stranded loops. Extension of the low cleaving hammerhead ribozyme antisense arms by nucleotides that base pair with the single-stranded regions facilitated the hammerhead ribozyme binding to longer RNA substrates (e.g. mRNA). In addition, a correlation between the in vitro and intracellular results was also found. Thus, the present study would facilitate the design of hammerhead ribozymes directed against higher order structured sites. Further, it emphasises the importance of detailed structural investigations of hammerhead ribozyme full-length target RNAs. PMID:9016562

  6. Regulation of human heme oxygenase in endothelial cells by using sense and antisense retroviral constructs.

    PubMed

    Quan, S; Yang, L; Abraham, N G; Kappas, A

    2001-10-01

    Our objective was to determine whether overexpression and underexpression of human heme oxygenase (HHO)-1 could be controlled on a long-term basis by introduction of the HO-1 gene in sense (S) and antisense (AS) orientation with an appropriate vector into endothelial cells. Retroviral vector (LXSN) containing viral long terminal repeat promoter-driven human HO-1 S (LSN-HHO-1) and LXSN vectors containing HHO-1 promoter (HOP)-controlled HHO-1 S and AS (LSN-HOP-HHO-1 and LSN-HOP-HHO-1-AS) sequences were constructed and used to transfect rat lung microvessel endothelial cells (RLMV cells) and human dermal microvessel endothelial cells (HMEC-1 cells). RLMV cells transduced with HHO-1 S expressed human HO-1 mRNA and HO-1 protein associated with elevation in total HO activity compared with nontransduced cells. Vector-mediated expression of HHO-1 S or AS under control of HOP resulted in effective production of HO-1 or blocked induction of endogenous human HO-1 in HMEC-1 cells, respectively. Overexpression of HO-1 AS was associated with a long-term decrease (45%) of endogenous HO-1 protein and an increase (167%) in unmetabolized exogenous heme in HMEC-1 cells. Carbon monoxide (CO) production in HO-1 S- or AS-transduced HMEC-1 cells after heme treatment was increased (159%) or decreased (50%), respectively, compared with nontransduced cells. HO-2 protein levels did not change. These findings demonstrate that HHO-1 S and AS retroviral constructs are functional in enhancing and reducing HO activity, respectively, and thus can be used to regulate cellular heme levels, the activity of heme-dependent enzymes, and the rate of heme catabolism to CO and bilirubin. PMID:11593038

  7. The landscape of antisense gene expression in human cancers.

    PubMed

    Balbin, O Alejandro; Malik, Rohit; Dhanasekaran, Saravana M; Prensner, John R; Cao, Xuhong; Wu, Yi-Mi; Robinson, Dan; Wang, Rui; Chen, Guoan; Beer, David G; Nesvizhskii, Alexey I; Chinnaiyan, Arul M

    2015-07-01

    High-throughput RNA sequencing has revealed more pervasive transcription of the human genome than previously anticipated. However, the extent of natural antisense transcripts' (NATs) expression, their regulation of cognate sense genes, and the role of NATs in cancer remain poorly understood. Here, we use strand-specific paired-end RNA sequencing (ssRNA-seq) data from 376 cancer samples covering nine tissue types to comprehensively characterize the landscape of antisense expression. We found consistent antisense expression in at least 38% of annotated transcripts, which in general is positively correlated with sense gene expression. Investigation of sense/antisense pair expressions across tissue types revealed lineage-specific, ubiquitous and cancer-specific antisense loci transcription. Comparisons between tumor and normal samples identified both concordant (same direction) and discordant (opposite direction) sense/antisense expression patterns. Finally, we provide OncoNAT, a catalog of cancer-related genes with significant antisense transcription, which will enable future investigations of sense/antisense regulation in cancer. Using OncoNAT we identified several functional NATs, including NKX2-1-AS1 that regulates the NKX2-1 oncogene and cell proliferation in lung cancer cells. Overall, this study provides a comprehensive account of NATs and supports a role for NATs' regulation of tumor suppressors and oncogenes in cancer biology. PMID:26063736

  8. The landscape of antisense gene expression in human cancers

    PubMed Central

    Balbin, O. Alejandro; Malik, Rohit; Dhanasekaran, Saravana M.; Prensner, John R.; Cao, Xuhong; Wu, Yi-Mi; Robinson, Dan; Wang, Rui; Chen, Guoan; Beer, David G.; Nesvizhskii, Alexey I.; Chinnaiyan, Arul M.

    2015-01-01

    High-throughput RNA sequencing has revealed more pervasive transcription of the human genome than previously anticipated. However, the extent of natural antisense transcripts’ (NATs) expression, their regulation of cognate sense genes, and the role of NATs in cancer remain poorly understood. Here, we use strand-specific paired-end RNA sequencing (ssRNA-seq) data from 376 cancer samples covering nine tissue types to comprehensively characterize the landscape of antisense expression. We found consistent antisense expression in at least 38% of annotated transcripts, which in general is positively correlated with sense gene expression. Investigation of sense/antisense pair expressions across tissue types revealed lineage-specific, ubiquitous and cancer-specific antisense loci transcription. Comparisons between tumor and normal samples identified both concordant (same direction) and discordant (opposite direction) sense/antisense expression patterns. Finally, we provide OncoNAT, a catalog of cancer-related genes with significant antisense transcription, which will enable future investigations of sense/antisense regulation in cancer. Using OncoNAT we identified several functional NATs, including NKX2-1-AS1 that regulates the NKX2-1 oncogene and cell proliferation in lung cancer cells. Overall, this study provides a comprehensive account of NATs and supports a role for NATs' regulation of tumor suppressors and oncogenes in cancer biology. PMID:26063736

  9. Antisense RNA: Function and Fate of Duplex RNA in Cells of Higher Eukaryotes

    PubMed Central

    Kumar, Madhur; Carmichael, Gordon G.

    1998-01-01

    There is ample evidence that cells of higher eukaryotes express double-stranded RNA molecules (dsRNAs) either naturally or as the result of viral infection or aberrant, bidirectional transcriptional readthrough. These duplex molecules can exist in either the cytoplasmic or nuclear compartments. Cells have evolved distinct ways of responding to dsRNAs, depending on the nature and location of the duplexes. Since dsRNA molecules are not thought to exist naturally within the cytoplasm, dsRNA in this compartment is most often associated with viral infections. Cells have evolved defensive strategies against such molecules, primarily involving the interferon response pathway. Nuclear dsRNA, however, does not induce interferons and may play an important posttranscriptional regulatory role. Nuclear dsRNA appears to be the substrate for enzymes which deaminate adenosine residues to inosine residues within the polynucleotide structure, resulting in partial or full unwinding. Extensively modified RNAs are either rapidly degraded or retained within the nucleus, whereas transcripts with few modifications may be transported to the cytoplasm, where they serve to produce altered proteins. This review summarizes our current knowledge about the function and fate of dsRNA in cells of higher eukaryotes and its potential manipulation as a research and therapeutic tool. PMID:9841677

  10. Inhibition of luciferase expression in transgenic Aedes aegypti mosquitoes by Sindbis virus expression of antisense luciferase RNA

    PubMed Central

    Johnson, Barbara W.; Olson, Ken E.; Allen-Miura, Tanya; Rayms-Keller, Alfredo; Carlson, Jonathan O.; Coates, Craig J.; Jasinskiene, Nijole; James, Anthony A.; Beaty, Barry J.; Higgs, Stephen

    1999-01-01

    A rapid and reproducible method of inhibiting the expression of specific genes in mosquitoes should further our understanding of gene function and may lead to the identification of mosquito genes that determine vector competence or are involved in pathogen transmission. We hypothesized that the virus expression system based on the mosquito-borne Alphavirus, Sindbis (Togaviridae), may efficiently transcribe effector RNAs that inhibit expression of a targeted mosquito gene. To test this hypothesis, germ-line-transformed Aedes aegypti that express luciferase (LUC) from the mosquito Apyrase promoter were intrathoracically inoculated with a double subgenomic Sindbis (dsSIN) virus TE/3′2J/anti-luc (Anti-luc) that transcribes RNA complementary to the 5′ end of the LUC mRNA. LUC activity was monitored in mosquitoes infected with either Anti-luc or control dsSIN viruses expressing unrelated antisense RNAs. Mosquitoes infected with Anti-luc virus exhibited 90% reduction in LUC compared with uninfected and control dsSIN-infected mosquitoes at 5 and 9 days postinoculation. We demonstrate that a gene expressed from the mosquito genome can be inhibited by using an antisense strategy. The dsSIN antisense RNA expression system is an important tool for studying gene function in vivo. PMID:10557332

  11. Inhibition of luciferase expression in transgenic Aedes aegypti mosquitoes by Sindbis virus expression of antisense luciferase RNA.

    PubMed

    Johnson, B W; Olson, K E; Allen-Miura, T; Rayms-Keller, A; Carlson, J O; Coates, C J; Jasinskiene, N; James, A A; Beaty, B J; Higgs, S

    1999-11-01

    A rapid and reproducible method of inhibiting the expression of specific genes in mosquitoes should further our understanding of gene function and may lead to the identification of mosquito genes that determine vector competence or are involved in pathogen transmission. We hypothesized that the virus expression system based on the mosquito-borne Alphavirus, Sindbis (Togaviridae), may efficiently transcribe effector RNAs that inhibit expression of a targeted mosquito gene. To test this hypothesis, germ-line-transformed Aedes aegypti that express luciferase (LUC) from the mosquito Apyrase promoter were intrathoracically inoculated with a double subgenomic Sindbis (dsSIN) virus TE/3'2J/anti-luc (Anti-luc) that transcribes RNA complementary to the 5' end of the LUC mRNA. LUC activity was monitored in mosquitoes infected with either Anti-luc or control dsSIN viruses expressing unrelated antisense RNAs. Mosquitoes infected with Anti-luc virus exhibited 90% reduction in LUC compared with uninfected and control dsSIN-infected mosquitoes at 5 and 9 days postinoculation. We demonstrate that a gene expressed from the mosquito genome can be inhibited by using an antisense strategy. The dsSIN antisense RNA expression system is an important tool for studying gene function in vivo. PMID:10557332

  12. Changes in Oleic Acid Content of Transgenic Soybeans by Antisense RNA Mediated Posttranscriptional Gene Silencing

    PubMed Central

    Zhang, Ling; Yang, Xiang-dong; Zhang, Yuan-yu; Yang, Jing; Qi, Guang-xun; Guo, Dong-quan; Xing, Guo-jie; Yao, Yao; Xu, Wen-jing; Li, Hai-yun; Li, Qi-yun; Dong, Ying-shan

    2014-01-01

    The Delta-12 oleate desaturase gene (FAD2-1), which converts oleic acid into linoleic acid, is the key enzyme determining the fatty acid composition of seed oil. In this study, we inhibited the expression of endogenous Delta-12 oleate desaturase GmFad2-1b gene by using antisense RNA in soybean Williams 82. By employing the soybean cotyledonary-node method, a part of the cDNA of soybean GmFad2-1b 801 bp was cloned for the construction of a pCAMBIA3300 vector under the soybean seed promoter BCSP. Leaf painting, LibertyLink strip, PCR, Southern blot, qRT-PCR, and fatty acid analysis were used to detect the insertion and expression of GmFad2-1b in the transgenic soybean lines. The results indicate that the metabolically engineered plants exhibited a significant increase in oleic acid (up to 51.71%) and a reduction in palmitic acid (to <3%) in their seed oil content. No structural differences were observed between the fatty acids of the transgenic and the nontransgenic oil extracts. PMID:25197629

  13. Gene Silencing by Gold Nanoshell-Mediated Delivery and Laser-Triggered Release of Antisense Oligonucleotide and siRNA

    PubMed Central

    Huschka, Ryan; Barhoumi, Aoune; Liu, Qing; Roth, Jack A.; Ji, Lin; Halas, Naomi J.

    2013-01-01

    The approach of RNA interference (RNAi)- using antisense DNA or RNA oligonucleotides to silence activity of a specific pathogenic gene transcript and reduce expression of the encoded protein- is very useful in dissecting genetic function and holds significant promise as a molecular therapeutic. A major obstacle in achieving gene silencing with RNAi technology is the systemic delivery of therapeutic oligonucleotides. Here we demonstrate an engineered gold nanoshell (NS)-based therapeutic oligonucleotide delivery vehicle, designed to release its cargo on demand upon illumination with a near-infrared (NIR) laser. A poly(L)lysine peptide (PLL) epilayer covalently attached to the NS surface (NS-PLL) is used to capture intact, single-stranded antisense DNA oligonucleotides, or alternatively, double-stranded short-interfering RNA (siRNA) molecules. Controlled release of the captured therapeutic oligonucleotides in each case is accomplished by continuous wave NIR laser irradiation at 800 nm, near the resonance wavelength of the nanoshell. Fluorescently tagged oligonucleotides were used to monitor the time-dependent release process and light-triggered endosomal release. A green fluorescent protein (GFP)-expressing human lung cancer H1299 cell line was used to determine cellular uptake and gene silencing mediated by the NS-PLL carrying GFP gene-specific single-stranded DNA antisense oligonucleotide (AON-GFP), or a double-stranded siRNA (siRNA-GFP), in vitro. Light-triggered delivery resulted in ∼ 47% and ∼49% downregulation of the targeted GFP expression by AON-GFP and siRNA-GFP, respectively. Cytotoxicity induced by both the NS-PLL delivery vector and by laser irradiation is minimal, as demonstrated by a XTT cell proliferation assay. PMID:22862291

  14. Gene silencing by gold nanoshell-mediated delivery and laser-triggered release of antisense oligonucleotide and siRNA.

    PubMed

    Huschka, Ryan; Barhoumi, Aoune; Liu, Qing; Roth, Jack A; Ji, Lin; Halas, Naomi J

    2012-09-25

    RNA interference (RNAi)--using antisense DNA or RNA oligonucleotides to silence activity of a specific pathogenic gene transcript and reduce expression of the encoded protein--is very useful in dissecting genetic function and holds significant promise as a molecular therapeutic. A major obstacle in achieving gene silencing with RNAi technology is the systemic delivery of therapeutic oligonucleotides. Here we demonstrate an engineered gold nanoshell (NS)-based therapeutic oligonucleotide delivery vehicle, designed to release its cargo on demand upon illumination with a near-infrared (NIR) laser. A poly-L-lysine peptide (PLL) epilayer covalently attached to the NS surface (NS-PLL) is used to capture intact, single-stranded antisense DNA oligonucleotides, or alternatively, double-stranded short-interfering RNA (siRNA) molecules. Controlled release of the captured therapeutic oligonucleotides in each case is accomplished by continuous wave NIR laser irradiation at 800 nm, near the resonance wavelength of the nanoshell. Fluorescently tagged oligonucleotides were used to monitor the time-dependent release process and light-triggered endosomal release. A green fluorescent protein (GFP)-expressing human lung cancer H1299 cell line was used to determine cellular uptake and gene silencing mediated by the NS-PLL carrying GFP gene-specific single-stranded DNA antisense oligonucleotide (AON-GFP), or a double-stranded siRNA (siRNA-GFP), in vitro. Light-triggered delivery resulted in ~47% and ~49% downregulation of the targeted GFP expression by AON-GFP and siRNA-GFP, respectively. Cytotoxicity induced by both the NS-PLL delivery vector and by laser irradiation is minimal, as demonstrated by a XTT cell proliferation assay. PMID:22862291

  15. Revealing natural antisense transcripts from Plasmodium vivax isolates: evidence of genome regulation in complicated malaria.

    PubMed

    Boopathi, P A; Subudhi, Amit Kumar; Garg, Shilpi; Middha, Sheetal; Acharya, Jyoti; Pakalapati, Deepak; Saxena, Vishal; Aiyaz, Mohammed; Chand, Bipin; Mugasimangalam, Raja C; Kochar, Sanjay K; Sirohi, Parmendra; Kochar, Dhanpat K; Das, Ashis

    2013-12-01

    Plasmodium vivax is the most geographically widespread human malaria parasite causing approximately 130-435 million infections annually. It is an economic burden in many parts of the world and poses a public health challenge along with the other Plasmodium sp. The biology of this parasite is less studied and poorly understood, in spite of these facts. Emerging evidence of severe complications due to infections by this parasite provides an impetus to focus research on the same. Investigating the parasite directly from infected patients is the best way to study its biology and pathogenic mechanisms. Gene expression studies of this parasite directly obtained from the patients has provided evidence of gene regulation resulting in varying amount of transcript levels in the different blood stages. The mechanisms regulating gene expression in malaria parasites are not well understood. Discovery of Natural Antisense Transcripts (NATs) in Plasmodium falciparum has suggested that these might play an important role in regulating gene expression. We report here the genome-wide occurrence of NATs in P. vivax parasites from patients with differing clinical symptoms. A total of 1348 NATs against annotated gene loci have been detected using a custom designed microarray with strand specific probes. Majority of NATs identified from this study shows positive correlation with the expression pattern of the sense (S) transcript. Our data also shows condition specific expression patterns of varying S and antisense (AS) transcript levels. Genes with AS transcripts enrich to various biological processes. To our knowledge this is the first report on the presence of NATs from P. vivax obtained from infected patients with different disease complications. The data suggests differential regulation of gene expression in diverse clinical conditions, as shown by differing sense/antisense ratios and would lead to future detailed investigations of gene regulation. PMID:24121022

  16. [Connection of magnetic antisense probe with SK-Br-3 oncocyte mRNA nucleotide detected by high resolution atomic force microscope].

    PubMed

    Tan, Shude; Ouyang, Yu; Li, Xinyou; Wen, Ming; Li, Shaolin

    2011-06-01

    The present paper is aimed to detect superparamagnetic iron oxide labeled c-erbB2 oncogene antisense oligonucleotide probe (magnetic antisense probe) connected with SK-Br-3 oncocyte mRNA nucleotide by high resolution atomic force microscope (AFM). We transfected SK-Br-3 oncocyte with magnetic antisense probe, then observed the cells by AFM with high resolution and detected protein expression and magnetic resonance imagine (MRI). The high resolution AFM clearly showed the connection of the oligonucleotide remote end of magnetic antisense probe with the mRNA nucleotide of oncocyte. The expression of e-erbB2 protein in SK-Br3 cells were highly inhibited by using magnetic antisense probe. We then obtained the lowest signal to noise ratio (SNR) of SK-Br-3 oncocyte transfected with magnetic antisense probe by MRI (P<0.05). These experiments demonstrated that the high resolution AFM could be used to show the binding of magnetic antisense probe and SK-Br-3 mRNA of tumor cell nuclear. PMID:21774198

  17. Evidence for a major role of antisense RNAs in cyanobacterial gene regulation

    PubMed Central

    Georg, Jens; Voß, Björn; Scholz, Ingeborg; Mitschke, Jan; Wilde, Annegret; Hess, Wolfgang R

    2009-01-01

    Information on the numbers and functions of naturally occurring antisense RNAs (asRNAs) in eubacteria has thus far remained incomplete. Here, we screened the model cyanobacterium Synechocystis sp. PCC 6803 for asRNAs using four different methods. In the final data set, the number of known noncoding RNAs rose from 6 earlier identified to 60 and of asRNAs from 1 to 73 (28 were verified using at least three methods). Among these, there are many asRNAs to housekeeping, regulatory or metabolic genes, as well as to genes encoding electron transport proteins. Transferring cultures to high light, carbon-limited conditions or darkness influenced the expression levels of several asRNAs, suggesting their functional relevance. Examples include the asRNA to rpl1, which accumulates in a light-dependent manner and may be required for processing the L11 r-operon and the SyR7 noncoding RNA, which is antisense to the murF 5′ UTR, possibly modulating murein biosynthesis. Extrapolated to the whole genome, ∼10% of all genes in Synechocystis are influenced by asRNAs. Thus, chromosomally encoded asRNAs may have an important function in eubacterial regulatory networks. PMID:19756044

  18. Pathogenic C9ORF72 Antisense Repeat RNA Forms a Double Helix with Tandem C:C Mismatches.

    PubMed

    Dodd, David W; Tomchick, Diana R; Corey, David R; Gagnon, Keith T

    2016-03-01

    Expansion of a GGGGCC/CCCCGG repeat sequence in the first intron of the C9ORF72 gene is a leading cause of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). In this combined disorder, called c9FTD/ALS, the expansion is bidirectionally transcribed into sense and antisense repeat RNA associated with disease. To better understand the role of C9ORF72 repeat RNA in molecular disease pathology, we determined crystal structures of a [(CCCCGG)3(CCCC)] model antisense repeat RNA to 1.47 Å resolution. The RNA structure was an A-form-like double helix composed of repeating and regularly spaced tandem C:C mismatch pairs that perturbed helical geometry and surface charge. Solution studies revealed a preference for A-form-like helical conformations as the repeat number increased. Results provide a structural starting point for rationalizing the contribution of repeat RNA to c9FTD/ALS molecular disease mechanisms and for developing molecules to target C9ORF72 repeat RNA as potential therapeutics. PMID:26878348

  19. Complex organisation and structure of the ghrelin antisense strand gene GHRLOS, a candidate non-coding RNA gene

    PubMed Central

    Seim, Inge; Carter, Shea L; Herington, Adrian C; Chopin, Lisa K

    2008-01-01

    Background The peptide hormone ghrelin has many important physiological and pathophysiological roles, including the stimulation of growth hormone (GH) release, appetite regulation, gut motility and proliferation of cancer cells. We previously identified a gene on the opposite strand of the ghrelin gene, ghrelinOS (GHRLOS), which spans the promoter and untranslated regions of the ghrelin gene (GHRL). Here we further characterise GHRLOS. Results We have described GHRLOS mRNA isoforms that extend over 1.4 kb of the promoter region and 106 nucleotides of exon 4 of the ghrelin gene, GHRL. These GHRLOS transcripts initiate 4.8 kb downstream of the terminal exon 4 of GHRL and are present in the 3' untranslated exon of the adjacent gene TATDN2 (TatD DNase domain containing 2). Interestingly, we have also identified a putative non-coding TATDN2-GHRLOS chimaeric transcript, indicating that GHRLOS RNA biogenesis is extremely complex. Moreover, we have discovered that the 3' region of GHRLOS is also antisense, in a tail-to-tail fashion to a novel terminal exon of the neighbouring SEC13 gene, which is important in protein transport. Sequence analyses revealed that GHRLOS is riddled with stop codons, and that there is little nucleotide and amino-acid sequence conservation of the GHRLOS gene between vertebrates. The gene spans 44 kb on 3p25.3, is extensively spliced and harbours multiple variable exons. We have also investigated the expression of GHRLOS and found evidence of differential tissue expression. It is highly expressed in tissues which are emerging as major sites of non-coding RNA expression (the thymus, brain, and testis), as well as in the ovary and uterus. In contrast, very low levels were found in the stomach where sense, GHRL derived RNAs are highly expressed. Conclusion GHRLOS RNA transcripts display several distinctive features of non-coding (ncRNA) genes, including 5' capping, polyadenylation, extensive splicing and short open reading frames. The gene is also

  20. Does the linear Sry transcript function as a ceRNA for miR-138? The sense of antisense

    PubMed Central

    Granados-Riveron, Javier Tadeo; Aquino-Jarquin, Guillermo

    2014-01-01

    Recently, the sex determining region Y ( Sry) and the cerebellar degeneration-related protein 1 ( CDR1as) RNA transcripts have been described to function as a new class of post-transcriptional regulatory RNAs that behave as circular endogenous RNA sponges for the micro RNAs (miRNAs) miR-138 and miR-7, respectively. A special feature of the Sry gene is its ability to generate linear and circular transcripts, both transcribed in the sense orientation. Here we remark that both sense (e.g. Sry RNA) and antisense (e.g. CDR1as) transcripts could circularize and behave as miRNAs sponges, and importantly, that also protein-coding segments of mRNAs could also assume this role. Thus, it is reasonable to think that the linear Sry sense transcript could additionally act as a miRNA sponge, or as an endogenous competing RNA for miR-138. PMID:25580223

  1. Targeted degradation of sense and antisense C9orf72 RNA foci as therapy for ALS and frontotemporal degeneration

    PubMed Central

    Lagier-Tourenne, Clotilde; Baughn, Michael; Rigo, Frank; Sun, Shuying; Liu, Patrick; Li, Hai-Ri; Jiang, Jie; Watt, Andrew T.; Chun, Seung; Katz, Melanie; Qiu, Jinsong; Sun, Ying; Ling, Shuo-Chien; Zhu, Qiang; Polymenidou, Magdalini; Drenner, Kevin; Artates, Jonathan W.; McAlonis-Downes, Melissa; Markmiller, Sebastian; Hutt, Kasey R.; Pizzo, Donald P.; Cady, Janet; Harms, Matthew B.; Baloh, Robert H.; Vandenberg, Scott R.; Yeo, Gene W.; Fu, Xiang-Dong; Bennett, C. Frank; Cleveland, Don W.; Ravits, John

    2013-01-01

    Expanded hexanucleotide repeats in the chromosome 9 open reading frame 72 (C9orf72) gene are the most common genetic cause of ALS and frontotemporal degeneration (FTD). Here, we identify nuclear RNA foci containing the hexanucleotide expansion (GGGGCC) in patient cells, including white blood cells, fibroblasts, glia, and multiple neuronal cell types (spinal motor, cortical, hippocampal, and cerebellar neurons). RNA foci are not present in sporadic ALS, familial ALS/FTD caused by other mutations (SOD1, TDP-43, or tau), Parkinson disease, or nonneurological controls. Antisense oligonucleotides (ASOs) are identified that reduce GGGGCC-containing nuclear foci without altering overall C9orf72 RNA levels. By contrast, siRNAs fail to reduce nuclear RNA foci despite marked reduction in overall C9orf72 RNAs. Sustained ASO-mediated lowering of C9orf72 RNAs throughout the CNS of mice is demonstrated to be well tolerated, producing no behavioral or pathological features characteristic of ALS/FTD and only limited RNA expression alterations. Genome-wide RNA profiling identifies an RNA signature in fibroblasts from patients with C9orf72 expansion. ASOs targeting sense strand repeat-containing RNAs do not correct this signature, a failure that may be explained, at least in part, by discovery of abundant RNA foci with C9orf72 repeats transcribed in the antisense (GGCCCC) direction, which are not affected by sense strand-targeting ASOs. Taken together, these findings support a therapeutic approach by ASO administration to reduce hexanucleotide repeat-containing RNAs and raise the potential importance of targeting expanded RNAs transcribed in both directions. PMID:24170860

  2. Maternal mRNA knockdown studies: antisense experiments using the host-transfer technique in X. laevis and X. tropicalis

    PubMed Central

    Olson, David J.; Hulstrand, Alissa M.; Houston, Douglas W.

    2014-01-01

    SUMMARY The ability to inhibit the activity of maternally stored gene products in Xenopus has led to numerous insights into early developmental mechanisms. Oocytes can be cultured and manipulated in vitro and then implanted into the body cavity of a host female to make them competent for fertilization. Here, we summarize the methods for obtaining, culturing and fertilizing Xenopus oocytes, with the goal of inhibiting maternal gene function through antisense oligonucleotide-mediated mRNA knockdown. We describe a simplified technique for implanting donor oocytes into host females using intraperitoneal injection. Also, we present optimized methods for performing the host-transfer procedure with X. tropicalis oocytes. PMID:22956088

  3. Downstream Antisense Transcription Predicts Genomic Features That Define the Specific Chromatin Environment at Mammalian Promoters

    PubMed Central

    Lavender, Christopher A.; Hoffman, Jackson A.; Trotter, Kevin W.; Gilchrist, Daniel A.; Bennett, Brian D.; Burkholder, Adam B.; Fargo, David C.; Archer, Trevor K.

    2016-01-01

    Antisense transcription is a prevalent feature at mammalian promoters. Previous studies have primarily focused on antisense transcription initiating upstream of genes. Here, we characterize promoter-proximal antisense transcription downstream of gene transcription starts sites in human breast cancer cells, investigating the genomic context of downstream antisense transcription. We find extensive correlations between antisense transcription and features associated with the chromatin environment at gene promoters. Antisense transcription downstream of promoters is widespread, with antisense transcription initiation observed within 2 kb of 28% of gene transcription start sites. Antisense transcription initiates between nucleosomes regularly positioned downstream of these promoters. The nucleosomes between gene and downstream antisense transcription start sites carry histone modifications associated with active promoters, such as H3K4me3 and H3K27ac. This region is bound by chromatin remodeling and histone modifying complexes including SWI/SNF subunits and HDACs, suggesting that antisense transcription or resulting RNA transcripts contribute to the creation and maintenance of a promoter-associated chromatin environment. Downstream antisense transcription overlays additional regulatory features, such as transcription factor binding, DNA accessibility, and the downstream edge of promoter-associated CpG islands. These features suggest an important role for antisense transcription in the regulation of gene expression and the maintenance of a promoter-associated chromatin environment. PMID:27487356

  4. Downstream Antisense Transcription Predicts Genomic Features That Define the Specific Chromatin Environment at Mammalian Promoters.

    PubMed

    Lavender, Christopher A; Cannady, Kimberly R; Hoffman, Jackson A; Trotter, Kevin W; Gilchrist, Daniel A; Bennett, Brian D; Burkholder, Adam B; Burd, Craig J; Fargo, David C; Archer, Trevor K

    2016-08-01

    Antisense transcription is a prevalent feature at mammalian promoters. Previous studies have primarily focused on antisense transcription initiating upstream of genes. Here, we characterize promoter-proximal antisense transcription downstream of gene transcription starts sites in human breast cancer cells, investigating the genomic context of downstream antisense transcription. We find extensive correlations between antisense transcription and features associated with the chromatin environment at gene promoters. Antisense transcription downstream of promoters is widespread, with antisense transcription initiation observed within 2 kb of 28% of gene transcription start sites. Antisense transcription initiates between nucleosomes regularly positioned downstream of these promoters. The nucleosomes between gene and downstream antisense transcription start sites carry histone modifications associated with active promoters, such as H3K4me3 and H3K27ac. This region is bound by chromatin remodeling and histone modifying complexes including SWI/SNF subunits and HDACs, suggesting that antisense transcription or resulting RNA transcripts contribute to the creation and maintenance of a promoter-associated chromatin environment. Downstream antisense transcription overlays additional regulatory features, such as transcription factor binding, DNA accessibility, and the downstream edge of promoter-associated CpG islands. These features suggest an important role for antisense transcription in the regulation of gene expression and the maintenance of a promoter-associated chromatin environment. PMID:27487356

  5. Upping the Antisense Ante.

    ERIC Educational Resources Information Center

    Weiss, Rick

    1991-01-01

    Discussed is a designer-drug technology called antisense which blocks messenger RNA's ability to carry information to protein producing sites in the cell. The applications of this drug to AIDS research, cancer therapy, and other diseases are discussed. (KR)

  6. A novel antisense long noncoding RNA within the IGF1R gene locus is imprinted in hematopoietic malignancies.

    PubMed

    Sun, Jingnan; Li, Wei; Sun, Yunpeng; Yu, Dehai; Wen, Xue; Wang, Hong; Cui, Jiuwei; Wang, Guanjun; Hoffman, Andrew R; Hu, Ji-Fan

    2014-09-01

    Dysregulation of the insulin-like growth factor type I receptor (IGF1R) has been implicated in the progression and therapeutic resistance of malignancies. In acute myeloid leukemia (AML) cells, IGF1R is one of the most abundantly phosphorylated receptor tyrosine kinases, promoting cell growth through the PI3K/Akt signaling pathway. However, little is known regarding the molecular mechanisms underlying IGF1R gene dysregulation in cancer. We discovered a novel intragenic long noncoding RNA (lncRNA) within the IGF1R locus, named IRAIN, which is transcribed in an antisense direction from an intronic promoter. The IRAIN lncRNA was expressed exclusively from the paternal allele, with the maternal counterpart being silenced. Using both reverse transcription-associated trap and chromatin conformation capture assays, we demonstrate that this lncRNA interacts with chromatin DNA and is involved in the formation of an intrachromosomal enhancer/promoter loop. Knockdown of IRAIN lncRNA with shRNA abolishes this intrachromosomal interaction. In addition, IRAIN was downregulated both in leukemia cell lines and in blood obtained from high-risk AML patients. These data identify IRAIN as a new imprinted lncRNA that is involved in long-range DNA interactions. PMID:25092925

  7. Control of enzymatic browning in potato (Solanum tuberosum L.) by sense and antisense RNA from tomato polyphenol oxidase.

    PubMed

    Coetzer, C; Corsini, D; Love, S; Pavek, J; Tumer, N

    2001-02-01

    Polyphenol oxidase (PPO) activity of Russet Burbank potato was inhibited by sense and antisense PPO RNAs expressed from a tomato PPO cDNA under the control of the 35S promoter from the cauliflower mosaic virus. Transgenic Russet Burbank potato plants from 37 different lines were grown in the field. PPO activity and the level of enzymatic browning were measured in the tubers harvested from the field. Of the tubers from 28 transgenic lines that were sampled, tubers from 5 lines exhibited reduced browning. The level of PPO activity correlated with the reduction in enzymatic browning in these lines. These results indicate that expression of tomato PPO RNA in sense or antisense orientation inhibits PPO activity and enzymatic browning in the major commercial potato cultivar. Expression of tomato PPO RNA in sense orientation led to the greatest decrease in PPO activity and enzymatic browning, possibly due to cosuppression. These results suggest that expression of closely related heterologous genes can be used to prevent enzymatic browning in a wide variety of food crops without the application of various food additives. PMID:11262007

  8. EGO-1, a C. elegans RdRP, Modulates Gene Expression via Production of mRNA-Templated Short Antisense RNAs

    PubMed Central

    Maniar, Jay M.; Fire, Andrew Z.

    2011-01-01

    SUMMARY Background The development of the germline in Caenorhabditis elegans is a complex process involving the regulation of thousands of genes in a coordinated manner. Several genes required for small RNA biogenesis and function are among those required for the proper organization of the germline. EGO-1 is a putative RNA-directed RNA polymerase (RdRP) that is required for multiple aspects of C. elegans germline development and efficient RNAi of germline-expressed genes. RdRPs have been proposed to act through a variety of mechanisms including the post-transcriptional targeting of specific mRNAs as well as through a direct interaction with chromatin. Despite extensive investigation, the molecular role of EGO-1 has remained enigmatic. Results Here we use high-throughput small RNA and messenger RNA sequencing to investigate EGO-1 function. We found that EGO-1 is required to produce a distinct pool of small RNAs antisense to a number of germline-expressed mRNAs through several developmental stages. These potential mRNA targets fall into distinct classes, including genes required for kinetochore and nuclear pore assembly, histone-modifying activities and centromeric proteins. We also found several RNAi-related genes to be targets of EGO-1. Finally, we show a strong association between the loss of small RNAs and the rise of mRNA levels in ego-1(−) animals. Conclusions Our data support the conclusion that EGO-1 produces triphosphorylated small RNAs derived from mRNA templates and that these small RNAs modulate gene expression through the targeting of their cognate mRNAs. PMID:21396820

  9. ADAR2-Mediated Editing of miR-214 and miR-122 Precursor and Antisense RNA Transcripts in Liver Cancers

    PubMed Central

    Liu, Wan-Hsin; Chen, Chao-Hung; Yeh, Kun-Huei; Li, Chiao-Ling; Wu, Yi-Jinn; Chen, Ding-Shinn; Chen, Pei-Jer; Yeh, Shiou-Hwei

    2013-01-01

    A growing list of microRNAs (miRNAs) show aberrant expression patterns in hepatocellular carcinoma (HCC), but the regulatory mechanisms largely remain unclear. RNA editing catalyzed by members of the adenosine deaminase acting on the RNA (ADAR) family could target the miRNA precursors and affect the biogenesis process. Therefore, we investigate whether RNA editing could be one mechanism contributing to the deregulation of specific miRNAs in HCC. By overexpression of individual ADARs in hepatoma cells, RNA editing on the precursors of 16 miRNAs frequently deregulated in HCC was screened by a sensitive high-resolution melting platform. The results identified RNA precursors of miR-214 and miR-122 as potential targets edited by ADAR2. A subset of HCC showing elevated ADAR2 verified the major editings identified in ARAR2 overexpressed hepatoma cells, either with A-to-I or U-to-C changes. The unusual U-to-C editing at specific residues was demonstrated as being attributed to the A-to-I editing on the RNA transcripts complementary to the pri-miRNAs. The editing event caused a decrease of the RNA transcript complementary to pri-miR-214, which led to the decrease of pri-miR-214 and miR-214 and resulted in the increased protein level of its novel target gene Rab15. In conclusion, the current study discovered ADAR2-mediated editing of the complementary antisense transcripts as a novel mechanism for regulating the biogenesis of specific miRNAs during hepatocarcinogenesis. PMID:24386085

  10. Fas-antisense long noncoding RNA is differentially expressed during maturation of human erythrocytes and confers resistance to Fas-mediated cell death.

    PubMed

    Villamizar, Olga; Chambers, Christopher B; Mo, Yin-Yuan; Torry, Donald S; Hofstrand, Reese; Riberdy, Janice M; Persons, Derek A; Wilber, Andrew

    2016-05-01

    Long noncoding RNAs (lncRNAs) interact with other RNAs, DNA and/or proteins to regulate gene expression during development. Erythropoiesis is one developmental process that is tightly controlled throughout life to ensure accurate red blood cell production and oxygen transport to tissues. Thus, homeostasis is critical and maintained by competitive outcomes of pro- and anti-apoptotic pathways. LncRNAs are expressed during blood development; however, specific functions are largely undefined. Here, a culture model of human erythropoiesis revealed that lncRNA Fas-antisense 1 (Fas-AS1 or Saf) was induced during differentiation through the activity of essential erythroid transcription factors GATA-1 and KLF1. Saf was also negatively regulated by NF-κB, where decreasing NF-κB activity levels tracked with increasing transcription of Saf. Furthermore, Saf over-expression in erythroblasts derived from CD34(+) hematopoietic stem/progenitor cells of healthy donors reduced surface levels of Fas and conferred protection against Fas-mediated cell death signals. These studies reveal a novel lncRNA-regulated mechanism that modulates a critical cell death program during human erythropoiesis. PMID:27067490

  11. A newly discovered member of the fatty acid desaturase gene family: a non-coding, antisense RNA gene to delta5-desaturase.

    PubMed

    Dreesen, Thomas D; Adamson, Aaron W; Tekle, Michael; Tang, Chongren; Cho, Hyekung P; Clarke, Steven D; Gettys, Thomas W

    2006-08-01

    The rate limiting steps in the conversion of 18-carbon unsaturated fatty acids to 20- and 22-carbon products are catalyzed by two desaturase enzymes (Delta5-desaturase and Delta6-desaturase) found within a lipid desaturase gene cluster. Careful examination of this cluster revealed the existence of a conventionally spliced (human) and an intronless (mouse and rat) non-coding RNA gene, reverse Delta5-desaturase, which is transcribed from the opposite strand of the Delta5-desaturase gene. The 654 bp human reverse Delta5-desaturase transcript contains 269 nucleotides that are complementary to exon 1 and intron 1 of the Delta5-desaturase transcript, and the 3'-end of this sequence contains a 143 nucleotide stretch that is 100% complementary to the 5'-end of the Delta5-desaturase. The rat and mouse transcripts are 1355 and 690 bp long and complementary to a portion of the first intron and the entire first exon of their respective Delta5-desaturases. All reverse Delta5-desaturase transcripts contain several stop codons in all frames suggesting that they do not encode a peptide. Reverse Delta5-desaturase RNA was detected in all rat tissues where Delta5-desaturase is expressed, and the transition between fasting and refeeding produced a significant increase in reverse Delta5-desaturase RNA relative to Delta5-desaturase mRNA. Transient expression of reverse Delta5-desaturase in CHO cells stably transformed with Delta5-desaturase produced a modest decrease in Delta5-desaturase mRNA (30%), but lowered Delta5-desaturase enzymatic activity by >70%. More importantly, a diet enriched in fish oil produced a reciprocal increase in reverse Delta5-desaturase mRNA and decrease in Delta5-desaturase mRNA that was accompanied by a 5-6-fold decrease in Delta5-desaturase enzyme activity. These findings support a significant role for reverse Delta5-desaturase as a natural antisense regulator of Delta5-desaturase. PMID:16846730

  12. The reduction in small ribosomal subunit abundance in ethanol-stressed cells of Bacillus subtilis is mediated by a SigB-dependent antisense RNA.

    PubMed

    Mars, Ruben A T; Mendonça, Karoline; Denham, Emma L; van Dijl, Jan Maarten

    2015-10-01

    One of the best-characterized general stress responses in bacteria is the σB-mediated stress response of the Gram-positive soil bacterium Bacillus subtilis. The σB regulon contains approximately 200 protein-encoding genes and 136 putative regulatory RNAs. One of these σB-dependent RNAs, named S1136-S1134, was recently mapped as being transcribed from the S1136 promoter on the opposite strand of the essential rpsD gene, which encodes the ribosomal primary-binding protein S4. Accordingly, S1136-S1134 transcription results in an rpsD-overlapping antisense RNA (asRNA). Upon exposure of B. subtilis to ethanol, the S1136 promoter was found to be induced, while rpsD transcription was downregulated. By quantitative PCR, we show that the activation of transcription from the S1136 promoter is directly responsible for the downregulation of rpsD upon ethanol exposure. We also show that this downregulation of rpsD leads to a reduced level of the small (30S) ribosomal subunit upon ethanol stress. The activation of the S1136 promoter thus represents the first example of antisense transcription-mediated regulation in the general stress response of B. subtilis and implicates the reduction of ribosomal protein abundance as a new aspect in the σB-dependent stress response. We propose that the observed reduction in the level of the small ribosomal subunit, which contains the ribosome-decoding center, may protect B. subtilis cells against misreading and spurious translation of possibly toxic aberrant peptides under conditions of ethanol stress. PMID:26115952

  13. Transgenic male-sterile plant induced by an unedited atp9 gene is restored to fertility by inhibiting its expression with antisense RNA.

    PubMed Central

    Zabaleta, E; Mouras, A; Hernould, M; Suharsono; Araya, A

    1996-01-01

    We have previously shown that the expression of an unedited atp9 chimeric gene correlated with male-sterile phenotype in transgenic tobacco plant. To study the relationship between the expression of chimeric gene and the male-sterile trait, hemizygous and homozygous transgenic tobacco lines expressing the antisense atp9 RNA were constructed. The antisense producing plants were crossed with a homozygous male-sterile line, and the F1 progeny was analyzed. The offspring from crosses between homozygous lines produced only male-fertile plants, suggesting that the expression antisense atp9 RNA abolishes the effect of the unedited chimeric gene. In fact, the plants restored to male fertility showed a dramatic reduction of the unedited atp9 transcript levels, resulting in normal flower development and seed production. These results support our previous observation that the expression of unedited atp9 gene can induce male sterility. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8855343

  14. From Cryptic Toward Canonical Pre-mRNA Splicing in Pompe Disease: a Pipeline for the Development of Antisense Oligonucleotides.

    PubMed

    Bergsma, Atze J; In 't Groen, Stijn Lm; Verheijen, Frans W; van der Ploeg, Ans T; Pijnappel, Wwm Pim

    2016-01-01

    While 9% of human pathogenic variants have an established effect on pre-mRNA splicing, it is suspected that an additional 20% of otherwise classified variants also affect splicing. Aberrant splicing includes disruption of splice sites or regulatory elements, or creation or strengthening of cryptic splice sites. For the majority of variants, it is poorly understood to what extent and how these may affect splicing. We have identified cryptic splicing in an unbiased manner. Three types of cryptic splicing were analyzed in the context of pathogenic variants in the acid α-glucosidase gene causing Pompe disease. These involved newly formed deep intronic or exonic cryptic splice sites, and a natural cryptic splice that was utilized due to weakening of a canonical splice site. Antisense oligonucleotides that targeted the identified cryptic splice sites repressed cryptic splicing at the expense of canonical splicing in all three cases, as shown by reverse-transcriptase-quantitative polymerase chain reaction analysis and by enhancement of acid α-glucosidase enzymatic activity. This argues for a competition model for available splice sites, including intact or weakened canonical sites and natural or newly formed cryptic sites. The pipeline described here can detect cryptic splicing and correct canonical splicing using antisense oligonucleotides to restore the gene defect. PMID:27623443

  15. Cellular Selenoprotein mRNA Tethering via Antisense Interactions with Ebola and HIV-1 mRNAs May Impact Host Selenium Biochemistry.

    PubMed

    Taylor, Ethan Will; Ruzicka, Jan A; Premadasa, Lakmini; Zhao, Lijun

    2016-01-01

    Regulation of protein expression by non-coding RNAs typically involves effects on mRNA degradation and/or ribosomal translation. The possibility of virus-host mRNA-mRNA antisense tethering interactions (ATI) as a gain-of-function strategy, via the capture of functional RNA motifs, has not been hitherto considered. We present evidence that ATIs may be exploited by certain RNA viruses in order to tether the mRNAs of host selenoproteins, potentially exploiting the proximity of a captured host selenocysteine insertion sequence (SECIS) element to enable the expression of virally-encoded selenoprotein modules, via translation of in-frame UGA stop codons as selenocysteine. Computational analysis predicts thermodynamically stable ATIs between several widely expressed mammalian selenoprotein mRNAs (e.g., isoforms of thioredoxin reductase) and specific Ebola virus mRNAs, and HIV-1 mRNA, which we demonstrate via DNA gel shift assays. The probable functional significance of these ATIs is further supported by the observation that, in both viruses, they are located in close proximity to highly conserved in-frame UGA stop codons at the 3' end of open reading frames that encode essential viral proteins (the HIV-1 nef protein and the Ebola nucleoprotein). Significantly, in HIV/AIDS patients, an inverse correlation between serum selenium and mortality has been repeatedly documented, and clinical benefits of selenium in the context of multi-micronutrient supplementation have been demonstrated in several well-controlled clinical trials. Hence, in the light of our findings, the possibility of a similar role for selenium in Ebola pathogenesis and treatment merits serious investigation. PMID:26369818

  16. Cellular Selenoprotein mRNA Tethering via Antisense Interactions with Ebola and HIV-1 mRNAs May Impact Host Selenium Biochemistry

    PubMed Central

    Taylor, Ethan Will; Ruzicka, Jan A.; Premadasa, Lakmini; Zhao, Lijun

    2016-01-01

    Regulation of protein expression by non-coding RNAs typically involves effects on mRNA degradation and/or ribosomal translation. The possibility of virus-host mRNA-mRNA antisense tethering interactions (ATI) as a gain-of-function strategy, via the capture of functional RNA motifs, has not been hitherto considered. We present evidence that ATIs may be exploited by certain RNA viruses in order to tether the mRNAs of host selenoproteins, potentially exploiting the proximity of a captured host selenocysteine insertion sequence (SECIS) element to enable the expression of virally-encoded selenoprotein modules, via translation of in-frame UGA stop codons as selenocysteine. Computational analysis predicts thermodynamically stable ATIs between several widely expressed mammalian selenoprotein mRNAs (e.g., isoforms of thioredoxin reductase) and specific Ebola virus mRNAs, and HIV-1 mRNA, which we demonstrate via DNA gel shift assays. The probable functional significance of these ATIs is further supported by the observation that, in both viruses, they are located in close proximity to highly conserved in-frame UGA stop codons at the 3′ end of open reading frames that encode essential viral proteins (the HIV-1 nef protein and the Ebola nucleoprotein). Significantly, in HIV/AIDS patients, an inverse correlation between serum selenium and mortality has been repeatedly documented, and clinical benefits of selenium in the context of multi-micronutrient supplementation have been demonstrated in several well-controlled clinical trials. Hence, in the light of our findings, the possibility of a similar role for selenium in Ebola pathogenesis and treatment merits serious investigation. PMID:26369818

  17. Antisense RNA Controls LRP1 Sense Transcript Expression Through Interaction With a Chromatin-Associated Protein, HMGB2

    PubMed Central

    Yamanaka, Yasunari; Faghihi, Mohammad Ali; Magistri, Marco; Alvarez-Garcia, Oscar; Lotz, Martin; Wahlestedt, Claes

    2015-01-01

    SUMMARY Long non-coding RNAs (lncRNAs) including natural antisense transcripts (NATs) are expressed more extensively than previously anticipated, and have widespread roles in regulating gene expression. Nevertheless, the molecular mechanisms of action of the majority of NATs remain largely unknown. Here we identify a NAT of Low-density lipoprotein receptor-related protein 1 (Lrp1), referred to as Lrp1-AS, that negatively regulates Lrp1 expression. We show that Lrp1-AS directly binds to High mobility group box 2 (Hmgb2) and inhibits the activity of Hmgb2 to enhance Srebp1a-dependent transcription of Lrp1. Short oligonucleotides targeting Lrp1-AS inhibit the interaction of antisense transcript and Hmgb2 protein, and increase Lrp1 expression by enhancing Hmgb2 activity. qRT-PCR analysis of Alzheimer’s disease brain samples and aged-matched controls revealed upregulation of LRP1-AS and downregulation of LRP1. Our data suggest a new regulatory mechanism whereby a NAT interacts with a ubiquitous chromatin-associated protein to modulate its activity in a locus-specific fashion. PMID:25937287

  18. Gene silencing of HIV chemokine receptors using ribozymes and single-stranded antisense RNA.

    PubMed

    Qureshi, Amer; Zheng, Richard; Parlett, Terry; Shi, Xiaoju; Balaraman, Priyadhashini; Cheloufi, Sihem; Murphy, Brendan; Guntermann, Christine; Eagles, Peter

    2006-03-01

    The chemokine receptors CXCR4 and CCR5 are required for HIV-1 to enter cells, and the progression of HIV-1 infection to AIDS involves a switch in the co-receptor usage of the virus from CCR5 to CXCR4. These receptors therefore make attractive candidates for therapeutic intervention, and we have investigated the silencing of their genes by using ribozymes and single-stranded antisense RNAs. In the present study, we demonstrate using ribozymes that a depletion of CXCR4 and CCR5 mRNAs can be achieved simultaneously in human PBMCs (peripheral blood mononuclear cells), cells commonly used by the virus for infection and replication. Ribozyme activity leads to an inhibition of the cell-surface expression of both CCR5 and CXCR4, resulting in a significant inhibition of HIV-1 replication when PBMCs are challenged with the virus. In addition, we show that small single-stranded antisense RNAs can also be used to silence CCR5 and CXCR4 genes when delivered to PBMCs. This silencing is caused by selective degradation of receptor mRNAs. PMID:16293105

  19. Gene silencing of HIV chemokine receptors using ribozymes and single-stranded antisense RNA

    PubMed Central

    Qureshi, Amer; Zheng, Richard; Parlett, Terry; Shi, Xiaoju; Balaraman, Priyadhashini; Cheloufi, Sihem; Murphy, Brendan; Guntermann, Christine; Eagles, Peter

    2005-01-01

    The chemokine receptors CXCR4 and CCR5 are required for HIV-1 to enter cells, and the progression of HIV-1 infection to AIDS involves a switch in the co-receptor usage of the virus from CCR5 to CXCR4. These receptors therefore make attractive candidates for therapeutic intervention, and we have investigated the silencing of their genes by using ribozymes and single-stranded antisense RNAs. In the present study, we demonstrate using ribozymes that a depletion of CXCR4 and CCR5 mRNAs can be achieved simultaneously in human PBMCs (peripheral blood mononuclear cells), cells commonly used by the virus for infection and replication. Ribozyme activity leads to an inhibition of the cell-surface expression of both CCR5 and CXCR4, resulting in a significant inhibition of HIV-1 replication when PBMCs are challenged with the virus. In addition, we show that small single-stranded antisense RNAs can also be used to silence CCR5 and CXCR4 genes when delivered to PBMCs. This silencing is caused by selective degradation of receptor mRNAs. PMID:16293105

  20. ChiTaRS 2.1--an improved database of the chimeric transcripts and RNA-seq data with novel sense-antisense chimeric RNA transcripts.

    PubMed

    Frenkel-Morgenstern, Milana; Gorohovski, Alessandro; Vucenovic, Dunja; Maestre, Lorena; Valencia, Alfonso

    2015-01-01

    Chimeric RNAs that comprise two or more different transcripts have been identified in many cancers and among the Expressed Sequence Tags (ESTs) isolated from different organisms; they might represent functional proteins and produce different disease phenotypes. The ChiTaRS 2.1 database of chimeric transcripts and RNA-Seq data (http://chitars.bioinfo.cnio.es/) is the second version of the ChiTaRS database and includes improvements in content and functionality. Chimeras from eight organisms have been collated including novel sense-antisense (SAS) chimeras resulting from the slippage of the sense and anti-sense intragenic regions. The new database version collects more than 29,000 chimeric transcripts and indicates the expression and tissue specificity for 333 entries confirmed by RNA-seq reads mapping the chimeric junction sites. User interface allows for rapid and easy analysis of evolutionary conservation of fusions, literature references and experimental data supporting fusions in different organisms. More than 1428 cancer breakpoints have been automatically collected from public databases and manually verified to identify their correct cross-references, genomic sequences and junction sites. As a result, the ChiTaRS 2.1 collection of chimeras from eight organisms and human cancer breakpoints extends our understanding of the evolution of chimeric transcripts in eukaryotes as well as their functional role in carcinogenic processes. PMID:25414346

  1. Reduction of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase Content by Antisense RNA Reduces Photosynthesis in Transgenic Tobacco Plants 1

    PubMed Central

    Hudson, Graham S.; Evans, John R.; von Caemmerer, Susanne; Arvidsson, Yvonne B. C.; Andrews, T. John

    1992-01-01

    A complementary DNA for the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) was cloned from tobacco (Nicotiana tabacum) and fused in the antisense orientation to the cauliflower mosaic virus 35S promoter. This antisense gene was introduced into the tobacco genome, and the resulting transgenic plants were analyzed to assess the effect of the antisense RNA on Rubisco activity and photosynthesis. The mean content of extractable Rubisco activity from the leaves of 10 antisense plants was 18% of the mean level of activity of control plants. The soluble protein content of the leaves of anti-small subunit plants was reduced by the amount equivalent to the reduction in Rubisco. There was little change in phosphoribulokinase activity, electron transport, and chlorophyll content, indicating that the loss of Rubisco did not affect these other components of photosynthesis. However, there was a significant reduction in carbonic anhydrase activity. The rate of CO2 assimilation measured at 1000 micromoles quanta per square meter per second, 350 microbars CO2, and 25°C was reduced by 63% (mean value) in the antisense plants and was limited by Rubisco activity over a wide range of intercellular CO2 partial pressures (pi). In control leaves, Rubisco activity only limited the rate of CO2 assimilation below a pi of 400 microbars. Despite the decrease in photosynthesis, there was no reduction in stomatal conductance in the antisense plants, and the stomata still responded to changes in pi. The unchanged conductance and lower CO2 assimilation resulted in a higher pi, which was reflected in greater carbon isotope discrimination in the leaves of the antisense plants. These results suggest that stomatal function is independent of total leaf Rubisco activity. PMID:16668627

  2. Bioinformatic and functional optimization of antisense phosphorodiamidate morpholino oligomers (PMOs) for therapeutic modulation of RNA splicing in muscle.

    PubMed

    Popplewell, Linda J; Graham, Ian R; Malerba, Alberto; Dickson, George

    2011-01-01

    Duchenne muscular dystrophy (DMD) is caused by mutations that disrupt the reading frame of the human DMD gene. Selective removal of exons flanking an out-of-frame DMD mutation can result in an in-frame mRNA transcript that may be translated into an internally deleted, Becker muscular dystrophy (BMD)-like, but functionally active dystrophin protein with therapeutic activity. Antisense oligonucleotides (AOs) can be designed to bind to complementary sequences in the targeted mRNA and modify pre-mRNA splicing to correct the reading frame of a mutated transcript so that gene expression is restored. AO-induced exon skipping producing functional truncated dystrophin exon has been demonstrated in animal models of DMD both in vitro and in vivo, and in DMD patient cells in vitro in culture, and in DMD muscle explants. More recently, AO-mediated exon skipping has been confirmed in DMD patients in Phase I clinical trials. However, it should be noted that personalized molecular medicine may be necessary, since the various reading frame-disrupting mutations are spread across the DMD gene. The different deletions that cause DMD would require skipping of different exons, which would require the optimization and clinical trial workup of many specific AOs. This chapter describes the methodologies available for the optimization of AOs, and in particular phosphorodiamidate morpholino oligomers (PMOs), for the targeted skipping of specific exons on the DMD gene. PMID:21194027

  3. Estradiol-Induced Transcriptional Regulation of Long Non-Coding RNA, HOTAIR.

    PubMed

    Bhan, Arunoday; Mandal, Subhrangsu S

    2016-01-01

    HOTAIR (HOX antisense intergenic RNA) is a 2.2 kb long non-coding RNA (lncRNA), transcribed from the antisense strand of homeobox C (HOXC) gene locus in chromosome 12. HOTAIR acts as a scaffolding lncRNA. It interacts and guides various chromatin-modifying complexes such as PRC2 (polycomb-repressive complex 2) and LSD1 (lysine-specific demethylase 1) to the target gene promoters leading to their gene silencing. Various studies have demonstrated that HOTAIR overexpression is associated with breast cancer. Recent studies from our laboratory demonstrate that HOTAIR is required for viability of breast cancer cells and is transcriptionally regulated by estradiol (E2) in vitro and in vivo. This chapter describes protocols for analysis of the HOTAIR promoter, cloning, transfection and dual luciferase assays, knockdown of protein synthesis by antisense oligonucleotides, and chromatin immunoprecipitation (ChIP) assay. These protocols are useful for studying the estrogen-mediated transcriptional regulation of lncRNA HOTAIR, as well as other protein coding genes and non-coding RNAs. PMID:26585152

  4. Sense and antisense transcripts of the developmentally regulated murine hsp70.2 gene are expressed in distinct and only partially overlapping areas in the adult brain

    NASA Technical Reports Server (NTRS)

    Murashov, A. K.; Wolgemuth, D. J.

    1996-01-01

    We have examined the spatial pattern of expression of a member of the hsp70 gene family, hsp70.2, in the mouse central nervous system. Surprisingly, RNA blot analysis and in situ hybridization revealed abundant expression of an 'antisense' hsp70.2 transcript in several areas of adult mouse brain. Two different transcripts recognized by sense and antisense riboprobes for the hsp70.2 gene were expressed in distinct and only partially overlapping neuronal populations. RNA blot analysis revealed low levels of the 2.7 kb transcript of hsp70.2 in several areas of the brain, with highest signal in the hippocampus. Abundant expression of a slightly larger (approximately 2.8 kb) 'antisense' transcript was detected in several brain regions, notably in the brainstem, cerebellum, mesencephalic tectum, thalamus, cortex, and hippocampus. In situ hybridization revealed that the sense and antisense transcripts were both predominantly neuronal and localized to the same cell types in the granular layer of the cerebellum, trapezoid nucleus of the superior olivary complex, locus coeruleus and hippocampus. The hsp70.2 antisense transcripts were particularly abundant in the frontal cortex, dentate gyrus, subthalamic nucleus, zona incerta, superior and inferior colliculi, central gray, brainstem, and cerebellar Purkinje cells. Our findings have revealed a distinct cellular and spatial localization of both sense and antisense transcripts, demonstrating a new level of complexity in the function of the heat shock genes.

  5. LncRNA HOTAIR: a master regulator of chromatin dynamics and cancer

    PubMed Central

    Bhan, Arunoday; Mandal, Subhrangsu S.

    2015-01-01

    Non-coding RNAs (ncRNAs) are emerging classes of regulatory RNA that play key roles in various cellular and physiological processes such as in gene regulation, chromatin dynamics, cell differentiation, development etc. NcRNAs are dysregulated in a variety of human disorders including cancers, neurological disorders, and immunological disorders. The mechanisms through which ncRNAs regulate various biological processes and human diseases still remain elusive. HOX antisense intergenic RNA (HOTAIR) is a recently discovered long non-coding RNA (lncRNA) that plays critical role in gene regulation and chromatin dynamics, appears to be misregulated in a variety of cancers. HOTAIR interacts with key epigenetic regulators such as histone methyltransferase PRC2 and histone demethylase LSD1 and regulates gene silencing. Here, we have reviewed recent advancements in understanding the functions and regulation of HOTAIR and its association with cancer and other diseases. PMID:26208723

  6. Using in-cell SHAPE-Seq and simulations to probe structure-function design principles of RNA transcriptional regulators.

    PubMed

    Takahashi, Melissa K; Watters, Kyle E; Gasper, Paul M; Abbott, Timothy R; Carlson, Paul D; Chen, Alan A; Lucks, Julius B

    2016-06-01

    Antisense RNA-mediated transcriptional regulators are powerful tools for controlling gene expression and creating synthetic gene networks. RNA transcriptional repressors derived from natural mechanisms called attenuators are particularly versatile, though their mechanistic complexity has made them difficult to engineer. Here we identify a new structure-function design principle for attenuators that enables the forward engineering of new RNA transcriptional repressors. Using in-cell SHAPE-Seq to characterize the structures of attenuator variants within Escherichia coli, we show that attenuator hairpins that facilitate interaction with antisense RNAs require interior loops for proper function. Molecular dynamics simulations of these attenuator variants suggest these interior loops impart structural flexibility. We further observe hairpin flexibility in the cellular structures of natural RNA mechanisms that use antisense RNA interactions to repress translation, confirming earlier results from in vitro studies. Finally, we design new transcriptional attenuators in silico using an interior loop as a structural requirement and show that they function as desired in vivo. This work establishes interior loops as an important structural element for designing synthetic RNA gene regulators. We anticipate that the coupling of experimental measurement of cellular RNA structure and function with computational modeling will enable rapid discovery of structure-function design principles for a diverse array of natural and synthetic RNA regulators. PMID:27103533

  7. Using in-cell SHAPE-Seq and simulations to probe structure–function design principles of RNA transcriptional regulators

    PubMed Central

    Takahashi, Melissa K.; Watters, Kyle E.; Gasper, Paul M.; Abbott, Timothy R.; Carlson, Paul D.; Chen, Alan A.

    2016-01-01

    Antisense RNA-mediated transcriptional regulators are powerful tools for controlling gene expression and creating synthetic gene networks. RNA transcriptional repressors derived from natural mechanisms called attenuators are particularly versatile, though their mechanistic complexity has made them difficult to engineer. Here we identify a new structure–function design principle for attenuators that enables the forward engineering of new RNA transcriptional repressors. Using in-cell SHAPE-Seq to characterize the structures of attenuator variants within Escherichia coli, we show that attenuator hairpins that facilitate interaction with antisense RNAs require interior loops for proper function. Molecular dynamics simulations of these attenuator variants suggest these interior loops impart structural flexibility. We further observe hairpin flexibility in the cellular structures of natural RNA mechanisms that use antisense RNA interactions to repress translation, confirming earlier results from in vitro studies. Finally, we design new transcriptional attenuators in silico using an interior loop as a structural requirement and show that they function as desired in vivo. This work establishes interior loops as an important structural element for designing synthetic RNA gene regulators. We anticipate that the coupling of experimental measurement of cellular RNA structure and function with computational modeling will enable rapid discovery of structure–function design principles for a diverse array of natural and synthetic RNA regulators. PMID:27103533

  8. Antisense RNA Inhibition of RbcS Gene Expression Reduces Rubisco Level and Photosynthesis in the C4 Plant Flaveria bidentis.

    PubMed

    Furbank, R. T.; Chitty, J. A.; Von Caemmerer, S.; Jenkins, CLD.

    1996-07-01

    The C4 dicot Flaveria bidentis was genetically transformed with an antisense RNA construct targeted to the nuclear-encoded gene for the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco; RbcS). RbcS mRNA levels in leaves of transformants were reduced by as much as 80% compared to wild-type levels, and extractable enzyme activity was reduced by up to 85%. There was no significant effect of transformation with the gene construct on levels of other photosynthetic enzymes. Antisense transformants with reduced Rubisco activity exhibited a stunted phenotype. Rates of photosynthesis were reduced in air at high light and over a range of CO2 concentrations but were unaffected at low light. From these results we conclude that, as is the case in C3 plants, Rubisco activity is a major determinant of photosynthetic flux in C4 plants under high light intensities and air levels of CO2. PMID:12226324

  9. Antisense RNA inactivation of gene expression of a cell-cell adhesion protein (gp64) in the cellular slime mold Polysphondylium pallidum.

    PubMed

    Funamoto, S; Ochiai, H

    1996-05-01

    The gp64 protein of Polysphondylium pallidum has been shown to mediate EDTA-stable cell-cell adhesion. To explore the functional role of gp64, we made an antisense RNA expression construct designed to prevent the gene expression of gp64; the construct was introduced into P. pallidum cells and the transformants were characterised. The antisense RNA-expressing clone L3mc2 which had just been harvested at the growth phase tended to re-form in aggregates smaller in size than did the parental cells in either the presence or absence of 10 mM EDTA. In contrast, 6.5-hour starved L3mc2 cells remained considerably dissociated from each other after 5 minutes gyrating, although aggregation gradually increased by 50% during a further 55 minutes gyrating in the presence of 10 mM EDTA. Correspondingly, L3mc2 lacked specifically the cell-cell adhesion protein, gp64. We therefore conclude that the gp64 protein is involved in forming the EDTA-resistant cell-cell contact. In spite of the absence of gp64, L3mc2 exhibited normal developmental processes, a fact which demonstrates that another cell-cell adhesion system exists in the development of Polysphondylium. This is the first report in which an antisense RNA technique was successfully applied to Polysphondylium. PMID:8743948

  10. An antisense RNA controls synthesis of an SOS-induced toxin evolved from an antitoxin

    PubMed Central

    Kawano, Mitsuoki; Aravind, L; Storz, Gisela

    2007-01-01

    Only few small, regulatory RNAs encoded opposite another gene have been identified in bacteria. Here, we report the characterization of a locus where a small RNA (SymR) is encoded in cis to an SOS-induced gene whose product shows homology to the antitoxin MazE (SymE). Synthesis of the SymE protein is tightly repressed at multiple levels by the LexA repressor, the SymR RNA and the Lon protease. SymE co-purifies with ribosomes and overproduction of the protein leads to cell growth inhibition, decreased protein synthesis and increased RNA degradation. These properties are shared with several RNA endonuclease toxins of the toxin-antitoxin modules, and we show that the SymE protein represents evolution of a toxin from the AbrB fold, whose representatives are typically antitoxins. We suggest that SymE promotion of RNA cleavage may be important for the recycling of RNAs damaged under SOS-inducing conditions. PMID:17462020

  11. Genetic Transformation of Citrus Paradisi with Antisense and untranslatable RNA-dependent RNA Polymerase Genes of Citrus Tristeza Closterovirus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Expression of the RNA-dependent RNA polymerase (RdRp) of Citrus tristeza virus (CTV) was studied in vivo and in vitro using a polyclonal antiserum raised against the recombinant CTV-RdRp protein. Although 56 kDa CTV-RdRp is thought to be expressed by a +1 translational frameshift at the carboxyl te...

  12. Cis-Antisense Transcription Gives Rise to Tunable Genetic Switch Behavior: A Mathematical Modeling Approach

    PubMed Central

    Bordoy, Antoni E.; Chatterjee, Anushree

    2015-01-01

    Antisense transcription has been extensively recognized as a regulatory mechanism for gene expression across all kingdoms of life. Despite the broad importance and extensive experimental determination of cis-antisense transcription, relatively little is known about its role in controlling cellular switching responses. Growing evidence suggests the presence of non-coding cis-antisense RNAs that regulate gene expression via antisense interaction. Recent studies also indicate the role of transcriptional interference in regulating expression of neighboring genes due to traffic of RNA polymerases from adjacent promoter regions. Previous models investigate these mechanisms independently, however, little is understood about how cells utilize coupling of these mechanisms in advantageous ways that could also be used to design novel synthetic genetic devices. Here, we present a mathematical modeling framework for antisense transcription that combines the effects of both transcriptional interference and cis-antisense regulation. We demonstrate the tunability of transcriptional interference through various parameters, and that coupling of transcriptional interference with cis-antisense RNA interaction gives rise to hypersensitive switches in expression of both antisense genes. When implementing additional positive and negative feed-back loops from proteins encoded by these genes, the system response acquires a bistable behavior. Our model shows that combining these multiple-levels of regulation allows fine-tuning of system parameters to give rise to a highly tunable output, ranging from a simple-first order response to biologically complex higher-order response such as tunable bistable switch. We identify important parameters affecting the cellular switch response in order to provide the design principles for tunable gene expression using antisense transcription. This presents an important insight into functional role of antisense transcription and its importance towards

  13. Natural antisense transcripts associated with salinity response in alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Natural antisense transcripts (NATs) are long non-coding RNAs (lncRNAs) complimentary to the messenger (sense) RNA (Wang et al. 2014). Many of them are involved in regulation of their own sense transcripts thus playing pivotal biological roles in all processes of organismal development and responses...

  14. Mechanisms and Regulation of Alternative Pre-mRNA Splicing

    PubMed Central

    Lee, Yeon

    2015-01-01

    Precursor messenger RNA (pre-mRNA) splicing is a critical step in the posttranscriptional regulation of gene expression, providing significant expansion of the functional proteome of eukaryotic organisms with limited gene numbers. Split eukaryotic genes contain intervening sequences or introns disrupting protein-coding exons, and intron removal occurs by repeated assembly of a large and highly dynamic ribonucleoprotein complex termed the spliceosome, which is composed of five small nuclear ribonucleoprotein particles, U1, U2, U4/U6, and U5. Biochemical studies over the past 10 years have allowed the isolation as well as compositional, functional, and structural analysis of splicing complexes at distinct stages along the spliceosome cycle. The average human gene contains eight exons and seven introns, producing an average of three or more alternatively spliced mRNA isoforms. Recent high-throughput sequencing studies indicate that 100% of human genes produce at least two alternative mRNA isoforms. Mechanisms of alternative splicing include RNA–protein interactions of splicing factors with regulatory sites termed silencers or enhancers, RNA–RNA base-pairing interactions, or chromatin-based effects that can change or determine splicing patterns. Disease-causing mutations can often occur in splice sites near intron borders or in exonic or intronic RNA regulatory silencer or enhancer elements, as well as in genes that encode splicing factors. Together, these studies provide mechanistic insights into how spliceosome assembly, dynamics, and catalysis occur; how alternative splicing is regulated and evolves; and how splicing can be disrupted by cis- and trans-acting mutations leading to disease states. These findings make the spliceosome an attractive new target for small-molecule, antisense, and genome-editing therapeutic interventions. PMID:25784052

  15. A cis-regulatory antisense RNA represses translation in Vibrio cholerae through extensive complementarity and proximity to the target locus

    PubMed Central

    Chang, Howard; Replogle, John Michael; Vather, Naomi; Tsao-Wu, Maya; Mistry, Ronak; Liu, Jane M

    2015-01-01

    As with all facultative pathogens, Vibrio cholerae must optimize its cellular processes to adapt to different environments with varying carbon sources and to environmental stresses. More specifically, in order to metabolize mannitol, V. cholerae must regulate the synthesis of MtlA, a mannitol transporter protein produced exclusively in the presence of mannitol. We previously showed that a cis-acting small RNA (sRNA) expressed by V. cholerae, MtlS, appears to post-transcriptionally downregulate the expression of mtlA and is produced in the absence of mannitol. We hypothesized that since it is complementary to the 5′ untranslated region (UTR) of mtlA mRNA, MtlS may affect synthesis of MtlA by forming an mtlA-MtlS complex that blocks translation of the mRNA through occlusion of its ribosome binding site. To test this hypothesis, we used in vitro translation assays in order to examine the role MtlS plays in mtlA regulation and found that MtlS is sufficient to suppress translation of transcripts harboring the 5′ UTR of mtlA. However, in a cellular context, the 5′ UTR of mtlA is not sufficient for targeted repression by endogenous MtlS; additional segments from the coding region of mtlA play a role in the ability of the sRNA to regulate translation of mtlA mRNA. Additionally, proximity of transcription sites between the sRNA and mRNA significantly affects the efficacy of MtlS. PMID:25826566

  16. Genome-wide analysis for discovery of new rice miRNA reveals natural antisense miRNA (nat-miRNAs)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Small RNAs (21-24nt) are involved in gene regulation through translation inhibition, mRNA cleavage, or directing chromatin modifications. In rice, currently ~240 miRNAs have been annotated. We sequenced more than four million small RNAs from rice and identified another 24 miRNA genes. Among these, w...

  17. Staphylococcus aureus RNAIII coordinately represses the synthesis of virulence factors and the transcription regulator Rot by an antisense mechanism

    PubMed Central

    Boisset, Sandrine; Geissmann, Thomas; Huntzinger, Eric; Fechter, Pierre; Bendridi, Nadia; Possedko, Maria; Chevalier, Clément; Helfer, Anne Catherine; Benito, Yvonne; Jacquier, Alain; Gaspin, Christine; Vandenesch, François; Romby, Pascale

    2007-01-01

    RNAIII is the intracellular effector of the quorum-sensing system in Staphylococcus aureus. It is one of the largest regulatory RNAs (514 nucleotides long) that are known to control the expression of a large number of virulence genes. Here, we show that the 3′ domain of RNAIII coordinately represses at the post-transcriptional level, the expression of mRNAs that encode a class of virulence factors that act early in the infection process. We demonstrate that the 3′ domain acts primarily as an antisense RNA and rapidly anneals to these mRNAs, forming long RNA duplexes. The interaction between RNAIII and the mRNAs results in repression of translation initiation and triggers endoribonuclease III hydrolysis. These processes are followed by rapid depletion of the mRNA pool. In addition, we show that RNAIII and its 3′ domain mediate translational repression of rot mRNA through a limited number of base pairings involving two loop–loop interactions. Since Rot is a transcriptional regulatory protein, we proposed that RNAIII indirectly acts on many downstream genes, resulting in the activation of the synthesis of several exoproteins. These data emphasize the multitude of regulatory steps affected by RNAIII and its 3′ domain in establishing a network of S. aureus virulence factors. PMID:17545468

  18. Characterization of the Regulation of CD46 RNA Alternative Splicing.

    PubMed

    Tang, Sze Jing; Luo, Shufang; Ho, Jia Xin Jessie; Ly, Phuong Thao; Goh, Eling; Roca, Xavier

    2016-07-01

    Here we present a detailed analysis of the alternative splicing regulation of human CD46, which generates different isoforms with distinct functions. CD46 is a ubiquitous membrane protein that protects host cells from complement and plays other roles in immunity, autophagy, and cell adhesion. CD46 deficiency causes an autoimmune disorder, and this protein is also involved in pathogen infection and cancer. Before this study, the mechanisms of CD46 alternative splicing remained unexplored even though dysregulation of this process has been associated with autoimmune diseases. We proved that the 5' splice sites of CD46 cassette exons 7 and 8 encoding extracellular domains are defined by noncanonical mechanisms of base pairing to U1 small nuclear RNA. Next we characterized the regulation of CD46 cassette exon 13, whose inclusion or skipping generates different cytoplasmic tails with distinct functions. Using splicing minigenes, we identified multiple exonic and intronic splicing enhancers and silencers that regulate exon 13 inclusion via trans-acting splicing factors like PTBP1 and TIAL1. Interestingly, a common splicing activator such as SRSF1 appears to repress CD46 exon 13 inclusion. We also report that expression of CD46 mRNA isoforms is further regulated by non-sense-mediated mRNA decay and transcription speed. Finally, we successfully manipulated CD46 exon 13 inclusion using antisense oligonucleotides, opening up opportunities for functional studies of the isoforms as well as for therapeutics for autoimmune diseases. This study provides insight into CD46 alternative splicing regulation with implications for its function in the immune system and for genetic disease. PMID:27226545

  19. Programmed fluctuations in sense/antisense transcript ratios drive sexual differentiation in S. pombe.

    PubMed

    Bitton, Danny A; Grallert, Agnes; Scutt, Paul J; Yates, Tim; Li, Yaoyong; Bradford, James R; Hey, Yvonne; Pepper, Stuart D; Hagan, Iain M; Miller, Crispin J

    2011-01-01

    Strand-specific RNA sequencing of S. pombe revealed a highly structured programme of ncRNA expression at over 600 loci. Waves of antisense transcription accompanied sexual differentiation. A substantial proportion of ncRNA arose from mechanisms previously considered to be largely artefactual, including improper 3' termination and bidirectional transcription. Constitutive induction of the entire spk1+, spo4+, dis1+ and spo6+ antisense transcripts from an integrated, ectopic, locus disrupted their respective meiotic functions. This ability of antisense transcripts to disrupt gene function when expressed in trans suggests that cis production at native loci during sexual differentiation may also control gene function. Consistently, insertion of a marker gene adjacent to the dis1+ antisense start site mimicked ectopic antisense expression in reducing the levels of this microtubule regulator and abolishing the microtubule-dependent 'horsetail' stage of meiosis. Antisense production had no impact at any of these loci when the RNA interference (RNAi) machinery was removed. Thus, far from being simply 'genome chatter', this extensive ncRNA landscape constitutes a fundamental component in the controls that drive the complex programme of sexual differentiation in S. pombe. PMID:22186733

  20. Programmed fluctuations in sense/antisense transcript ratios drive sexual differentiation in S. pombe

    PubMed Central

    Bitton, Danny A; Grallert, Agnes; Scutt, Paul J; Yates, Tim; Li, Yaoyong; Bradford, James R; Hey, Yvonne; Pepper, Stuart D; Hagan, Iain M; Miller, Crispin J

    2011-01-01

    Strand-specific RNA sequencing of S. pombe revealed a highly structured programme of ncRNA expression at over 600 loci. Waves of antisense transcription accompanied sexual differentiation. A substantial proportion of ncRNA arose from mechanisms previously considered to be largely artefactual, including improper 3′ termination and bidirectional transcription. Constitutive induction of the entire spk1+, spo4+, dis1+ and spo6+ antisense transcripts from an integrated, ectopic, locus disrupted their respective meiotic functions. This ability of antisense transcripts to disrupt gene function when expressed in trans suggests that cis production at native loci during sexual differentiation may also control gene function. Consistently, insertion of a marker gene adjacent to the dis1+ antisense start site mimicked ectopic antisense expression in reducing the levels of this microtubule regulator and abolishing the microtubule-dependent ‘horsetail' stage of meiosis. Antisense production had no impact at any of these loci when the RNA interference (RNAi) machinery was removed. Thus, far from being simply ‘genome chatter', this extensive ncRNA landscape constitutes a fundamental component in the controls that drive the complex programme of sexual differentiation in S. pombe. PMID:22186733

  1. Targeting the MicroRNA Passenger Strand for Regulating Therapeutic Transgenes.

    PubMed

    Kim, Sung Jin; Lee, Chang Ho; Lee, Seong-Wook

    2015-08-01

    Gene therapy strategies have been developed, which can tissue or disease specifically regulate expression of exogenous transgenes by means of endogenous microRNA (miRNA) activity. However, the use of an endogenous guide strand to regulate an exogenous transgene could affect expression of endogenous miRNA target genes. In this study, we developed a new regulatory system of exogenous transgene expression by targeting the passenger strand. We constructed reporter constructs harboring miRNA-122 guide or passenger target sites with perfect or imperfect complementarity. We observed downregulation of an exogenous transgene harboring the miRNA-122 target sites against either the guide or passenger strand in cells expressing the cognate miRNA or cells stably expressing the miRNA target site. Moreover, the transgene activity as well as the gene expression level increased specifically by intracellular introduction of the antisense RNA against the corresponding strand. Endogenous target gene expression was induced by the transgene construct harboring the miRNA guide strand target sites, but not the passenger strand target sites. Importantly, the therapeutic transgene activity was efficiently regulated by targeting the passenger strand. These results suggested that an approach to passenger strand-regulated expression of therapeutic transgenes could be applied more safely as a therapeutic tool. PMID:26076094

  2. Rational design of point mutation-selective antisense DNA targeted to codon 12 of Ha-ras mRNA in human cells.

    PubMed Central

    Duroux, I; Godard, G; Boidot-Forget, M; Schwab, G; Hélène, C; Saison-Behmoaras, T

    1995-01-01

    Antisense oligodeoxynucleotides targeted to Ha-ras mRNA have been designed to discriminate between the codon 12-mutated oncogene and the normal proto-oncogene. An in vitro assay using two different sources of RNase H (rabbit reticulocyte lysates and nuclear extract from HeLa cells) was used to characterize oligonucleotide binding to normal and mutated Ha-ras mRNA. Short oligonucleotides (12- or 13mers) centered on the mutation had a very high discriminatory efficiency. Longer oligonucleotides (16mers) did not discriminate efficiently between the mutated and the normal mRNA. We have tested the efficacy of dodecanucleotides to induce RNase H cleavage of the full-length mRNA, moving the target sequence from the loop to the stem region which is formed in the vicinity of mutated codon 12. The most selective oligonucleotides were centered on the mutation which is located near the junction between the loop and stem regions even though they were less efficient at inducing RNase H cleavage than those targeted to the loop region. The 12mer antisense oligonucleotide with the highest discriminatory power was selected for cell culture studies. This oligonucleotide inhibited the proliferation of a human cell line which had been transformed with the mutated Ha-ras gene (HBL100ras1) but had no effect on the parental cell line which was transfected with the vector DNA (HBL 100neo) and expressed only the normal Ha-ras gene. Growth inhibition of HBL100ras1 cells was associated with specific ablation of targeted Ha-ras mRNA as shown by RT-PCR. These results show that 'in vitro' evaluation using an RNase H assay allowed us to select an antisense oligonucleotide which elicited a selectivity towards point-mutated Ha-ras mRNA when added at 10 microM concentration to the culture medium of cells expressing wild type and mutated Ha-ras mRNA. Images PMID:7567450

  3. Role of sialosyl Lewis(a) in adhesion of colon cancer cells--the antisense RNA approach.

    PubMed

    Kłopocki, A G; Laskowska, A; Antoniewicz-Papis, J; Duk, M; Lisowska, E; Ugorski, M

    1998-04-01

    To study whether the adhesion of colon cancer cells to E-selectin can be directly affected by changes in the expression level of sialosyl Le(a) antigen we created a specific loss-of-function phenotype. A stable subclone (CX-1.1) with high expression of sialosyl Le(a) structure, obtained from a heterogenous population of colon carcinoma CX-1 cells, was transfected with an expression vector containing a fragment of cDNA for alpha1,3/4-fucosyltransferase in antisense orientation. After transfection, the cell line was isolated which did not express sialosyl Le(a) antigen and lacked the alpha1,3/4-fucosyltransferase activity, despite an unchanged level of mRNA specific for this enzyme. It was found that the specific lack of expression of sialosyl Le(a) carbohydrate structure on the surface of colon cancer cells completely abolished their adhesion to E-selectin. To evaluate which cellular glycoconjugates carry sialosyl Le(a) antigen, glycoproteins as well as glycolipids of CX-1.1 cells were analysed for the expression of this structure. Anti-sialosyl Le(a) antibodies detected multiple glycoprotein bands with apparent molecular masses of 65-280 kDa on western blots, and an intense band representing sialosyl Le(a)-ganglioside on a thin-layer chromatogram. Using O-sialoglycoprotease from Pasteurella haemolytica and an alkaline beta-elimination procedure, it was shown that protein-linked sialosyl Le(a) structures are carried mostly by mucin-type glycoproteins. However, treatment of CX-1.1 cells with O-sialoglycoprotease did not decrease either their binding to E-selectin-expressing Chinese hamster ovary cells, or binding of anti-sialosyl Le(a) antibodies to the cell surface. These results suggested that cleavage of sialomucins uncovered cryptic sialosyl Le(a)-ganglioside, which was inaccessible for the antibody and E-selectin in untreated cells. This hypothesis was confirmed to some extent by the higher accessibility of gangliosides to galactose oxidase on the surface of O

  4. Fine-Tuning of the Fatty Acid Pathway by Synthetic Antisense RNA for Enhanced (2S)-Naringenin Production from l-Tyrosine in Escherichia coli

    PubMed Central

    Wu, Junjun; Yu, Oliver; Du, Guocheng

    2014-01-01

    Malonyl coenzyme A (malonyl-CoA) is an important precursor for the synthesis of natural products, such as polyketides and flavonoids. The majority of this cofactor often is consumed for producing fatty acids and phospholipids, leaving only a small amount of cellular malonyl-CoA available for producing the target compound. The tuning of malonyl-CoA into heterologous pathways yields significant phenotypic effects, such as growth retardation and even cell death. In this study, fine-tuning of the fatty acid pathway in Escherichia coli with antisense RNA (asRNA) to balance the demands on malonyl-CoA for target-product synthesis and cell health was proposed. To establish an efficient asRNA system, the relationship between sequence and function for asRNA was explored. It was demonstrated that the gene-silencing effect of asRNA could be tuned by directing asRNA to different positions in the 5′-UTR (untranslated region) of the target gene. Based on this principle, the activity of asRNA was quantitatively tailored to balance the need for malonyl-CoA in cell growth and the production of the main flavonoid precursor, (2S)-naringenin. Appropriate inhibitory efficiency of the anti-fabB/fabF asRNA improved the production titer by 431% (391 mg/liter). Therefore, the strategy presented in this study provided a useful tool for the fine-tuning of endogenous gene expression in bacteria. PMID:25239896

  5. The Antisense RNA Approach: a New Application for In Vivo Investigation of the Stress Response of Oenococcus oeni, a Wine-Associated Lactic Acid Bacterium

    PubMed Central

    Darsonval, Maud; Msadek, Tarek; Alexandre, Hervé

    2015-01-01

    Oenococcus oeni is a wine-associated lactic acid bacterium mostly responsible for malolactic fermentation in wine. In wine, O. oeni grows in an environment hostile to bacterial growth (low pH, low temperature, and ethanol) that induces stress response mechanisms. To survive, O. oeni is known to set up transitional stress response mechanisms through the synthesis of heat stress proteins (HSPs) encoded by the hsp genes, notably a unique small HSP named Lo18. Despite the availability of the genome sequence, characterization of O. oeni genes is limited, and little is known about the in vivo role of Lo18. Due to the lack of genetic tools for O. oeni, an efficient expression vector in O. oeni is still lacking, and deletion or inactivation of the hsp18 gene is not presently practicable. As an alternative approach, with the goal of understanding the biological function of the O. oeni hsp18 gene in vivo, we have developed an expression vector to produce antisense RNA targeting of hsp18 mRNA. Recombinant strains were exposed to multiple stresses inducing hsp18 gene expression: heat shock and acid shock. We showed that antisense attenuation of hsp18 affects O. oeni survival under stress conditions. These results confirm the involvement of Lo18 in heat and acid tolerance of O. oeni. Results of anisotropy experiments also confirm a membrane-protective role for Lo18, as previous observations had already suggested. This study describes a new, efficient tool to demonstrate the use of antisense technology for modulating gene expression in O. oeni. PMID:26452552

  6. Reduction of coproporphyrinogen oxidase level by antisense RNA synthesis leads to deregulated gene expression of plastid proteins and affects the oxidative defense system.

    PubMed Central

    Kruse, E; Mock, H P; Grimm, B

    1995-01-01

    A full-length cDNA sequence encoding coproporphyrinogen oxidase was inserted in inverse orientation behind a CaMV promoter and transferred to tobacco (Nicotiana tabacum) by standard transformation techniques. Transformants showed reduced coproporphyrinogen oxidase activity and accumulation of photosensitive coproporphyrin(ogen), indicating antisense RNA expression. An inverse correlation was observed between the level of coproporphyrinogen oxidase and transformant phenotype. The latter is characterized by a broad range of growth retardation and necrosis, indicating oxidative leaf damage. Coproporphyrinogen is an apparent chromophore and its excitation finally leads to the production of reactive oxygen. Evidence is presented that indicates a direct correlation between the accumulation of non-metabolized coproporphyrinogen and oxidative damage to cellular structural components. Enzymatic and non-enzymatic antioxidants were investigated. Whereas superoxide dismutase activity increased in transgenic plants, catalase and ascorbate peroxidase activity remained constant. Tocopherol, rather than carotene or zeaxanthin, seemed to be involved in detoxification, indicating the putative localization and allocation of coproporphyrinogen. Expression of coproporphyrinogen oxidase antisense RNA did not significantly influence the level of other enzymes in the chlorophyll metabolic pathway, but deregulated gene expression of nuclear encoded plastid proteins. Accumulation of coproporphyrinogen and/or the resulting effects, such as oxidative stress, impairs a plastid/nuclear signal which may adapt gene expression to the plastid state. Images PMID:7641690

  7. Construction of a host-independent T7 expression system with small RNA regulation.

    PubMed

    Wang, Gang; Li, Qiang; Xu, Dikai; Cui, Mingxin; Sun, Xiao; Xu, Yanyan; Wang, Wenya

    2014-11-10

    It is desirable to build a universal and efficient protein expression system for wild-type prokaryotic strains in biotechnology industry and the outstanding T7 expression system could be a good candidate. However, the current utilization of T7 system depends on the specific DE3 lysogenic hosts, which severely limits its application in wild-type strains. In this study, a host-independent T7 expression system without relying on DE3 lysogenic hosts to provide T7 RNA Polymerase was developed. T7 RNA Polymerase gene (Gene1) and T7 Promoter were successfully integrated into a single plasmid with the regulation of proper antisense RNA to limit T7 RNA Polymerase expression at a non-lethal level. This host-independent T7 expression system realized efficient protein expression in 4 non-DE3 Escherichia coli strains and a wild-type Sinorhizobium strain TH572. PMID:25193711

  8. Targeting Cancer with Antisense Oligomers

    SciTech Connect

    Hnatowich, DJ

    2008-10-28

    With financial assistance from the Department of Energy, we have shown definitively that radiolabeled antisense DNAs and other oligomers will accumulate in target cancer cells in vitro and in vivo by an antisense mechanism. We have also shown that the number of mRNA targets for our antisense oligomers in the cancer cell types that we have investigated so far is sufficient to provide and antisense image and/or radiotherapy of cancer in mice. These studies have been reported in about 10 publications. However our observation over the past several years has shown that radiolabeled antisense oligomers administered intravenously in their native and naked form will accumulate and be retained in target xenografts by an antisense mechanism but will also accumulate at high levels in normal organs such as liver, spleen and kidneys. We have investigated unsuccessfully several commercially available vectors. Thus the use of radiolabeled antisense oligomers for the imaging of cancer must await novel approaches to delivery. This laboratory has therefore pursued two new paths, optical imaging of tumor and Auger radiotherapy. We are developing a novel method of optical imaging tumor using antisense oligomers with a fluorophore is administered while hybridized with a shorter complementary oligomer with an inhibitor. In culture and in tumored mice that the duplex remains intact and thus nonfluorescent until it encounters its target mRNA at which time it dissociates and the antisense oligomer binds along with its fluorophore to the target. Simultaneous with the above, we have also observed, as have others, that antisense oligomers migrate rapidly and quantitatively to the nucleus upon crossing cell membranes. The Auger electron radiotherapy path results from this observation since the nuclear migration properties could be used effectively to bring and to retain in the nucleus an Auger emitting radionuclide such as 111In or 125I bound to the antisense oligomer. Since the object becomes

  9. Hepatotoxicity of high affinity gapmer antisense oligonucleotides is mediated by RNase H1 dependent promiscuous reduction of very long pre-mRNA transcripts.

    PubMed

    Burel, Sebastien A; Hart, Christopher E; Cauntay, Patrick; Hsiao, Jill; Machemer, Todd; Katz, Melanie; Watt, Andy; Bui, Huynh-Hoa; Younis, Husam; Sabripour, Mahyar; Freier, Susan M; Hung, Gene; Dan, Amy; Prakash, T P; Seth, Punit P; Swayze, Eric E; Bennett, C Frank; Crooke, Stanley T; Henry, Scott P

    2016-03-18

    High affinity antisense oligonucleotides (ASOs) containing bicylic modifications (BNA) such as locked nucleic acid (LNA) designed to induce target RNA cleavage have been shown to have enhanced potency along with a higher propensity to cause hepatotoxicity. In order to understand the mechanism of this hepatotoxicity, transcriptional profiles were collected from the livers of mice treated with a panel of highly efficacious hepatotoxic or non-hepatotoxic LNA ASOs. We observed highly selective transcript knockdown in mice treated with non-hepatotoxic LNA ASOs, while the levels of many unintended transcripts were reduced in mice treated with hepatotoxic LNA ASOs. This transcriptional signature was concurrent with on-target RNA reduction and preceded transaminitis. Remarkably, the mRNA transcripts commonly reduced by toxic LNA ASOs were generally not strongly associated with any particular biological process, cellular component or functional group. However, they tended to have much longer pre-mRNA transcripts. We also demonstrate that the off-target RNA knockdown and hepatotoxicity is attenuated by RNase H1 knockdown, and that this effect can be generalized to high affinity modifications beyond LNA. This suggests that for a certain set of ASOs containing high affinity modifications such as LNA, hepatotoxicity can occur as a result of unintended off-target RNase H1 dependent RNA degradation. PMID:26553810

  10. Hepatotoxicity of high affinity gapmer antisense oligonucleotides is mediated by RNase H1 dependent promiscuous reduction of very long pre-mRNA transcripts

    PubMed Central

    Burel, Sebastien A.; Hart, Christopher E.; Cauntay, Patrick; Hsiao, Jill; Machemer, Todd; Katz, Melanie; Watt, Andy; Bui, Huynh-hoa; Younis, Husam; Sabripour, Mahyar; Freier, Susan M.; Hung, Gene; Dan, Amy; Prakash, T.P.; Seth, Punit P.; Swayze, Eric E.; Bennett, C. Frank; Crooke, Stanley T.; Henry, Scott P.

    2016-01-01

    High affinity antisense oligonucleotides (ASOs) containing bicylic modifications (BNA) such as locked nucleic acid (LNA) designed to induce target RNA cleavage have been shown to have enhanced potency along with a higher propensity to cause hepatotoxicity. In order to understand the mechanism of this hepatotoxicity, transcriptional profiles were collected from the livers of mice treated with a panel of highly efficacious hepatotoxic or non-hepatotoxic LNA ASOs. We observed highly selective transcript knockdown in mice treated with non-hepatotoxic LNA ASOs, while the levels of many unintended transcripts were reduced in mice treated with hepatotoxic LNA ASOs. This transcriptional signature was concurrent with on-target RNA reduction and preceded transaminitis. Remarkably, the mRNA transcripts commonly reduced by toxic LNA ASOs were generally not strongly associated with any particular biological process, cellular component or functional group. However, they tended to have much longer pre-mRNA transcripts. We also demonstrate that the off-target RNA knockdown and hepatotoxicity is attenuated by RNase H1 knockdown, and that this effect can be generalized to high affinity modifications beyond LNA. This suggests that for a certain set of ASOs containing high affinity modifications such as LNA, hepatotoxicity can occur as a result of unintended off-target RNase H1 dependent RNA degradation. PMID:26553810

  11. The rates of the major steps in the molecular mechanism of RNase H1-dependent antisense oligonucleotide induced degradation of RNA

    PubMed Central

    Vickers, Timothy A.; Crooke, Stanley T.

    2015-01-01

    Antisense oligonucleotides (ASOs) are most commonly designed to reduce targeted RNA via RNase H1-dependent degradation, however kinetic parameters for ASO-mediated targeting and subsequent cleavage and degradation of RNA in living cells are poorly understood. In this manuscript we use an inducible minigene system to determine the time course of ASO activity in the cell. Estimates of the time required for the ASO to enter and traverse the cell, scan the target mRNA, bind the cognate site, recruit RNase H1 and initiate cleavage, are presented in the context of transcription and mRNA processing rates. Data are also presented which indicate that rates for RNase H1-dependent ASO-mediated degradation of the targeted RNAs are different for nuclear-retained versus RNAs exported to the cytoplasm and that the level of RNase H1 in the cell and cellular compartments is limiting to the rate of ASO activity. In both cellular compartments RNase H1 ASOs essentially double the endogenous rates of clearance of the target RNA. Overexpression of Escherichia coli RNase H1 or the presence of multiple cognate sites each further increase the rate of target RNA degradation. PMID:26384424

  12. Inhibitory effect of spinal mGlu(5) receptor antisense oligonucleotide on the up-regulated expression of spinal G protein associated with chronic morphine treatment.

    PubMed

    Chen, Moxi; Zhang, Xiaoli; Xu, Hao; Ma, Xiaqing; Jiang, Wei; Xu, Tao

    2014-01-15

    Knockdown of spinal metabotropic glutamate 5 (mGlu5) receptor was shown to inhibit the development of intrathecal morphine antinociceptive tolerance. The present work was designed to evaluate the expression of spinal G-protein during morphine tolerance and knockdown of spinal mGlu5 receptor with antisense oligonucleotide (ODN). Rats were treated with saline, morphine, mGlu5 receptor antisense or mismatch ODN intrathecally. Behavioral tests were employed to test the thermal and mechanical pain thresholds. Five days later, rats were scarified and spinal expression of spinal Gαi, Gαo, Gαq and Gβ were detected. Consistent with the previous results, knockdown of spinal mGlu5 receptor could inhibit spinal morphine antinociceptive tolerance in behavioral tests (P<0.05). The mGlu5 receptor antisense ODN produced a significant reduction in mGlu5 receptor protein of about 56.6% compared with the control group (P<0.05). Expression of spinal Gαi, Gαo, Gαq and Gβ were up-regulated while morphine tolerance developed (P<0.05). Antisense ODN of spinal mGlu5 receptor, but not mismatched ODN, reduced the spinal dorsal horn levels of Gαi, Gαo, Gαs, Gαq and Gβ (P<0.05). We conclude that expression of spinal G (αi, αo, αs, αq and β) protein may be up-regulated after chronic morphine treatment which could be attenuated by knockdown of spinal mGlu5 receptor with antisense ODN. PMID:24296320

  13. Long non-coding antisense RNA KRT7-AS is activated in gastric cancers and supports cancer cell progression by increasing KRT7 expression

    PubMed Central

    Huang, Binbin; Song, Jee Hoon; Cheng, Yulan; Abraham, John M.; Ibrahim, Sariat; Sun, Zhenguo; Ke, Xiquan

    2015-01-01

    Alterations in long non-coding RNAs (lncRNAs) are associated with human carcinogenesis. One group of lncRNAs, which are antisense in orientation to coding mRNAs (ASs), have been recently described in cancers but are poorly understood. We sought to identify ASs involved in human gastric cancer (GC) and to elucidate their mechanisms of action in carcinogenesis. We performed massively parallel RNA sequencing in GCs and matched normal tissues, as well as in GC-derived and normal gastric epithelial cell lines. One AS, designated KRT7-AS, was selected due to its marked upregulation and concordant expression with its cognate sense counterpart, KRT7, in GC tissues and cell lines. KRT7-AS formed an RNA-RNA hybrid with KRT7 and controlled KRT7 expression at both the mRNA and the post-transcriptional levels. Moreover, forced overexpression of the KRT7-overlapping region (OL) of KRT7-AS (but not its non-KRT7-overlapping portions) increased keratin 7 protein levels in cells. Finally, forced overexpression of full-length (FL) KRT7-AS or OL KRT7-AS (but not its non-KRT7-overlapping regions) promoted GC cell proliferation and migration. We conclude that lncRNA KRT7-AS promotes GC, at least in part, by increasing KRT7 expression. PMID:26876208

  14. Regulation of Flavivirus RNA synthesis and replication.

    PubMed

    Selisko, Barbara; Wang, Chunling; Harris, Eva; Canard, Bruno

    2014-12-01

    RNA synthesis and replication of the members of the Flavivirus genus (including dengue, West Nile and Japanese encephalitis viruses) is regulated by a wide variety of mechanisms and actors. These include the sequestration of the RNA-dependent RNA polymerase (RdRp) for functions other than RNA synthesis, regulatory interactions with other viral and host proteins within the replication complex (RC), and regulatory elements within the RNA genome itself. In this review, we discuss our current knowledge of the multiple levels at which Flavivirus RNA synthesis is controlled. We aim to bring together two active research fields: the structural and functional biology of individual proteins of the RC and the impressive wealth of knowledge acquired regarding the viral genomic RNA. PMID:25462437

  15. Regulation of Flavivirus RNA synthesis and replication

    PubMed Central

    Selisko, Barbara; Wang, Chunling; Harris, Eva; Canard, Bruno

    2014-01-01

    RNA synthesis and replication of the members of the Flavivirus genus (including dengue, West Nile and Japanese encephalitis viruses) is regulated by a wide variety of mechanisms and actors. These include the sequestration of the RNA-dependent RNA polymerase (RdRp) for functions other than RNA synthesis, regulatory interactions with other viral and host proteins within the replication complex (RC), and regulatory elements within the RNA genome itself. In this review, we discuss our current knowledge of the multiple levels at which Flavivirus RNA synthesis is controlled. We aim to bring together two active research fields: the structural and functional biology of individual proteins of the RC and the impressive wealth of knowledge acquired regarding the viral genomic RNA. PMID:25462437

  16. PNPASE Regulates RNA Import into Mitochondria

    PubMed Central

    Wang, Geng; Chen, Hsiao-Wen; Oktay, Yavuz; Zhang, Jin; Allen, Eric L.; Smith, Geoffrey M.; Fan, Kelly C.; Hong, Jason S.; French, Samuel W.; McCaffery, J. Michael; Lightowlers, Robert N.; Morse, Herbert C.; Koehler, Carla M.; Teitell, Michael A.

    2010-01-01

    SUMMARY RNA import into mammalian mitochondria is considered essential for replication, transcription, and translation of the mitochondrial genome but the pathway(s) and factors that control this import are poorly understood. Previously, we localized polynucleotide phosphorylase (PNPASE), a 3′ → 5′ exoribonuclease and poly-A polymerase, in the mitochondrial intermembrane space, a location lacking resident RNAs. Here, we show a new role for PNPASE in regulating the import of nuclear-encoded RNAs into the mitochondrial matrix. PNPASE reduction impaired mitochondrial RNA processing and polycistronic transcripts accumulated. Augmented import of RNase P, 5S rRNA, and MRP RNAs depended on PNPASE expression and PNPASE–imported RNA interactions were identified. PNPASE RNA processing and import activities were separable and a mitochondrial RNA targeting signal was isolated that enabled RNA import in a PNPASE-dependent manner. Combined, these data strongly support an unanticipated role for PNPASE in mediating the translocation of RNAs into mitochondria. PMID:20691904

  17. Upstream Anti-sense Promoters are Hubs of Transcription Factor Binding and Active Histone Modifications

    PubMed Central

    Scruggs, Benjamin S.; Gilchrist, Daniel A.; Nechaev, Sergei; Muse, Ginger W.; Burkholder, Adam; Fargo, David C.; Adelman, Karen

    2015-01-01

    SUMMARY Anti-sense transcription originating upstream of mammalian protein-coding genes is a well-documented phenomenon, but remarkably little is known about the regulation or function of anti-sense promoters and the non-coding RNAs they generate. Here we define at nucleotide resolution the divergent transcription start sites (TSSs) near mouse mRNA genes. We find that coupled sense and anti-sense TSSs precisely define the boundaries of a nucleosome-depleted region (NDR) that is highly enriched in transcription factor (TF) motifs. Notably, as the distance between sense and anti-sense TSSs increases, so does the size of the NDR, the level of signal-dependent TF binding and gene activation. We further discover a group of anti-sense TSSs in macrophages with an enhancer-like chromatin signature. Interestingly, this signature identifies divergent promoters that are activated during immune challenge. We propose that anti-sense promoters serve as platforms for TF binding and establishment of active chromatin to further regulate or enhance sense-strand mRNA expression. PMID:26028540

  18. MicroRNA: Mechanism of Gene Regulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MicroRNA (miR) are a class of small RNAs that regulate gene expression by inhibiting translation of protein encoding transcripts through activation of a specific cellular pathway. The small RNA classified as miR are short sequences of 18-26 nucleotide long, encoded by nuclear genes with distinctive...

  19. RNA polymerase and the regulation of transcription

    SciTech Connect

    Reznikoff, W.S.; Gross, C.A.; Burgess, R.R.; Record, M.T.; Dahlberg, J.E.; Wickens, M.P.

    1987-01-01

    This book consists of eight sections, each containing several papers. The section titles are: RNA Polymerases; Transcription Initiation - Bacterial; Regulation of Bacterial Transcription Initiation; Stable RNA Synthesis in Eukaryotes: Chromatin Structure; Promoters; Enhancers; and the Global Control of Eukaryotic Transcription; Specific Eukaryotic Transcription Factors; Termination of Transcription; and Short Communications.

  20. Regulation of Cell Death by Transfer RNA

    PubMed Central

    2013-01-01

    Abstract Significance: Both transfer RNA (tRNA) and cytochrome c are essential molecules for the survival of cells. tRNA decodes mRNA codons into amino-acid-building blocks in protein in all organisms, whereas cytochrome c functions in the electron transport chain that powers ATP synthesis in mitochondrion-containing eukaryotes. Additionally, in vertebrates, cytochrome c that is released from mitochondria is a potent inducer of apoptosis, activating apoptotic proteins (caspases) in the cytoplasm to dismantle cells. A better understanding of both tRNA and cytochrome c is essential for an insight into the regulation of cell life and death. Recent Advances: A recent study showed that the mitochondrion-released cytochrome c can be removed from the cell-death pathway by tRNA molecules. The direct binding of cytochrome c by tRNA provides a mechanism for tRNA to regulate cell death, beyond its role in gene expression. Critical Issues: The nature of the tRNA–cytochrome c binding interaction remains unknown. The questions of how this interaction affects tRNA function, cellular metabolism, and apoptotic sensitivity are unanswered. Future Directions: Investigations into the critical issues raised above will improve the understanding of tRNA in the fundamental processes of cell death and metabolism. Such knowledge will inform therapies in cell death-related diseases. Antioxid. Redox Signal. 19, 583–594. PMID:23350625

  1. MicroRNA-30b-Mediated Regulation of Catalase Expression in Human ARPE-19 Cells

    PubMed Central

    Haque, Rashidul; Chun, Eugene; Howell, Jennifer C.; Sengupta, Trisha; Chen, Dan; Kim, Hana

    2012-01-01

    Background Oxidative injury to retinal pigment epithelium (RPE) and retinal photoreceptors has been linked to a number of retinal diseases, including age-related macular degeneration (AMD). Reactive oxygen species (ROS)-mediated gene expression has been extensively studied at transcriptional levels. Also, the post-transcriptional control of gene expression at the level of translational regulation has been recently reported. However, the microRNA (miRNA/miR)-mediated post-transcriptional regulation in human RPE cells has not been thoroughly looked at. Increasing evidence points to a potential role of miRNAs in diverse physiological processes. Methodology/Principal Findings We demonstrated for the first time in a human retinal pigment epithelial cell line (ARPE-19) that the post-transcriptional control of gene expression via miRNA modulation regulates human catalase, an important and potent component of cell's antioxidant defensive network, which detoxifies hydrogen peroxide (H2O2) radicals. Exposure to several stress-inducing agents including H2O2 has been reported to alter miRNA expression profile. Here, we demonstrated that a sublethal dose of H2O2 (200 µM) up-regulated the expression of miR-30b, a member of the miR-30 family, which inhibited the expression of endogenous catalase both at the transcript and protein levels. However, antisense (antagomirs) of miR-30b was not only found to suppress the miR-30b mimics-mediated inhibitions, but also to dramatically increase the expression of catalase even under an oxidant environment. Conclusions/Significance We propose that a microRNA antisense approach could enhance cytoprotective mechanisms against oxidative stress by increasing the antioxidant defense system. PMID:22880027

  2. MicroRNA-221 and -222 Regulate Radiation Sensitivity by Targeting the PTEN Pathway

    SciTech Connect

    Zhang Chunzhi; Kang Chunsheng; Wang Ping; Cao Yongzhen; Lv Zhonghong; Yu Shizhu; Wang Guangxiu; Zhang Anling; Jia Zhifan; Han Lei; Yang Chunying; Ishiyama, Hiromichi; Teh, Bin S.; Xu Bo; Pu Peiyu

    2011-05-01

    Purpose: MicroRNAs (miRNAs) are noncoding RNAs inhibiting expression of numerous target genes by posttranscriptional regulation. miRNA-221 and miRNA-222 (miRNA-221/-222) expression is elevated in radioresistant tumor cell lines; however, it is not known whether and how miRNAs control cellular responses to ionizing irradiation. Methods and Materials: We used bioinformatic analyses, luciferase reporter assay, and genetic knockdown and biochemical assays to characterize the regulation pathways of miRNA-221/-222 in response to radiation treatment. Results: We identified the PTEN gene as a target of miRNA-221/-222. Furthermore, we found that knocking down miRNA-221/-222 by antisense oligonucleotides upregulated PTEN expression. Upregulated PTEN expression suppressed AKT activity and increased radiation-induced apoptosis, resulting in enhancement of radiosensitivity in tumor cells. Conclusions: miRNA-221/-222 control radiation sensitivity by regulating the PTEN/AKT pathway and can be explored as novel targets for radiosensitization.

  3. Long Non-coding RNA BGas Regulates the Cystic Fibrosis Transmembrane Conductance Regulator.

    PubMed

    Saayman, Sheena M; Ackley, Amanda; Burdach, Jon; Clemson, Matthew; Gruenert, Dieter C; Tachikawa, Kiyoshi; Chivukula, Pad; Weinberg, Marc S; Morris, Kevin V

    2016-08-01

    Cystic fibrosis (CF) is a life-shortening genetic disease. The root cause of CF is heritable recessive mutations that affect the cystic fibrosis transmembrance conductance regulator (CFTR) gene and the subsequent expression and activity of encoded ion channels at the cell surface. We show that CFTR is regulated transcriptionally by the actions of a novel long noncoding RNA (lncRNA), designated as BGas, that emanates from intron 11 of the CFTR gene and is expressed in the antisense orientation relative to the protein coding sense strand. We find that BGas functions in concert with several proteins including HMGA1, HMGB1, and WIBG to modulate the local chromatin and DNA architecture of intron 11 of the CFTR gene and thereby affects transcription. Suppression of BGas or its associated proteins results in a gain of both CFTR expression and chloride ion function. The observations described here highlight a previously underappreciated mechanism of transcriptional control and suggest that BGas may serve as a therapeutic target for specifically activating expression of CFTR. PMID:27434588

  4. Antisense down-regulation of the strawberry β-galactosidase gene FaβGal4 increases cell wall galactose levels and reduces fruit softening

    PubMed Central

    Paniagua, Candelas; Blanco-Portales, Rosario; Barceló-Muñoz, Marta; García-Gago, Juan A.; Waldron, Keith W.; Quesada, Miguel A.; Muñoz-Blanco, Juan; Mercado, José A.

    2016-01-01

    Strawberry softening is characterized by an increase in the solubilization and depolymerization of pectins from cell walls. Galactose release from pectin side chains by β-galactosidase enzymes has been proposed as one reason for the increase in soluble pectins. A putative β-galactosidase gene, FaβGal4, has been identified using a custom-made oligonucleotide-based strawberry microarray platform. FaβGal4 was expressed mainly in the receptacle during fruit ripening, and was positively regulated by abscisic acid and negatively regulated by auxins. To ascertain the role of FaβGal4 in strawberry softening, transgenic plants containing an antisense sequence of this gene under the control of the CaMV35S promoter were generated. Phenotypic analyses were carried out in transgenic plants during three consecutive growing seasons, using non-transformed plants as control. Two out of nine independent transgenic lines yielded fruits that were 30% firmer than control at the ripe stage. FaβGal4 mRNA levels were reduced by 70% in ripe fruits from these selected transgenic lines, but they also showed significant silencing of FaβGal1, although the genes did not share significant similarity. These two transgenic lines also showed an increase in pectin covalently bound to the cell wall, extracted using Na2CO3. The amount of galactose in cell walls from transgenic fruits was 30% higher than in control; notably, the galactose increase was larger in the 1 M KOH fraction, which is enriched in hemicellulose. These results suggest that FaβGal4 participates in the solubilization of covalently bound pectins during ripening, reducing strawberry fruit firmness. PMID:26585222

  5. Antisense down-regulation of the strawberry β-galactosidase gene FaβGal4 increases cell wall galactose levels and reduces fruit softening.

    PubMed

    Paniagua, Candelas; Blanco-Portales, Rosario; Barceló-Muñoz, Marta; García-Gago, Juan A; Waldron, Keith W; Quesada, Miguel A; Muñoz-Blanco, Juan; Mercado, José A

    2016-02-01

    Strawberry softening is characterized by an increase in the solubilization and depolymerization of pectins from cell walls. Galactose release from pectin side chains by β-galactosidase enzymes has been proposed as one reason for the increase in soluble pectins. A putative β-galactosidase gene, FaβGal4, has been identified using a custom-made oligonucleotide-based strawberry microarray platform. FaβGal4 was expressed mainly in the receptacle during fruit ripening, and was positively regulated by abscisic acid and negatively regulated by auxins. To ascertain the role of FaβGal4 in strawberry softening, transgenic plants containing an antisense sequence of this gene under the control of the CaMV35S promoter were generated. Phenotypic analyses were carried out in transgenic plants during three consecutive growing seasons, using non-transformed plants as control. Two out of nine independent transgenic lines yielded fruits that were 30% firmer than control at the ripe stage. FaβGal4 mRNA levels were reduced by 70% in ripe fruits from these selected transgenic lines, but they also showed significant silencing of FaβGal1, although the genes did not share significant similarity. These two transgenic lines also showed an increase in pectin covalently bound to the cell wall, extracted using Na2CO3. The amount of galactose in cell walls from transgenic fruits was 30% higher than in control; notably, the galactose increase was larger in the 1 M KOH fraction, which is enriched in hemicellulose. These results suggest that FaβGal4 participates in the solubilization of covalently bound pectins during ripening, reducing strawberry fruit firmness. PMID:26585222

  6. Posttranscriptional gene regulation by long noncoding RNA.

    PubMed

    Yoon, Je-Hyun; Abdelmohsen, Kotb; Gorospe, Myriam

    2013-10-01

    Eukaryotic cells transcribe a vast number of noncoding RNA species. Among them, long noncoding RNAs (lncRNAs) have been widely implicated in the regulation of gene transcription. However, examples of posttranscriptional gene regulation by lncRNAs are emerging. Through extended base-pairing, lncRNAs can stabilize or promote the translation of target mRNAs, while partial base-pairing facilitates mRNA decay or inhibits target mRNA translation. In the absence of complementarity, lncRNAs can suppress precursor mRNA splicing and translation by acting as decoys of RNA-binding proteins or microRNAs and can compete for microRNA-mediated inhibition leading to increased expression of the mRNA. Through these regulatory mechanisms, lncRNAs can elicit differentiation, proliferation, and cytoprotective programs, underscoring the rising recognition of lncRNA roles in human disease. In this review, we summarize the mechanisms of posttranscriptional gene regulation by lncRNAs identified until now. PMID:23178169

  7. RNA-guided transcriptional regulation

    DOEpatents

    Church, George M.; Mali, Prashant G.; Esvelt, Kevin M.

    2016-02-23

    Methods of modulating expression of a target nucleic acid in a cell are provided including introducing into the cell a first foreign nucleic acid encoding one or more RNAs complementary to DNA, wherein the DNA includes the target nucleic acid, introducing into the cell a second foreign nucleic acid encoding a nuclease-null Cas9 protein that binds to the DNA and is guided by the one or more RNAs, introducing into the cell a third foreign nucleic acid encoding a transcriptional regulator protein or domain, wherein the one or more RNAs, the nuclease-null Cas9 protein, and the transcriptional regulator protein or domain are expressed, wherein the one or more RNAs, the nuclease-null Cas9 protein and the transcriptional regulator protein or domain co-localize to the DNA and wherein the transcriptional regulator protein or domain regulates expression of the target nucleic acid.

  8. The Role of Transcription Factors at Antisense-Expressing Gene Pairs in Yeast

    PubMed Central

    Mostovoy, Yulia; Thiemicke, Alexander; Hsu, Tiffany Y.; Brem, Rachel B.

    2016-01-01

    Genes encoded close to one another on the chromosome are often coexpressed, by a mechanism and regulatory logic that remain poorly understood. We surveyed the yeast genome for tandem gene pairs oriented tail-to-head at which expression antisense to the upstream gene was conserved across species. The intergenic region at most such tandem pairs is a bidirectional promoter, shared by the downstream gene mRNA and the upstream antisense transcript. Genomic analyses of these intergenic loci revealed distinctive patterns of transcription factor regulation. Mutation of a given transcription factor verified its role as a regulator in trans of tandem gene pair loci, including the proximally initiating upstream antisense transcript and downstream mRNA and the distally initiating upstream mRNA. To investigate cis-regulatory activity at such a locus, we focused on the stress-induced NAD(P)H dehydratase YKL151C and its downstream neighbor, the metabolic enzyme GPM1. Previous work has implicated the region between these genes in regulation of GPM1 expression; our mutation experiments established its function in rich medium as a repressor in cis of the distally initiating YKL151C sense RNA, and an activator of the proximally initiating YKL151C antisense RNA. Wild-type expression of all three transcripts required the transcription factor Gcr2. Thus, at this locus, the intergenic region serves as a focal point of regulatory input, driving antisense expression and mediating the coordinated regulation of YKL151C and GPM1. Together, our findings implicate transcription factors in the joint control of neighboring genes specialized to opposing conditions and the antisense transcripts expressed between them. PMID:27190003

  9. Long non-coding RNA HOTAIR regulates cyclin J via inhibition of microRNA-205 expression in bladder cancer

    PubMed Central

    Sun, X; Du, P; Yuan, W; Du, Z; Yu, M; Yu, X; Hu, T

    2015-01-01

    The level of microRNA-205 (miR-205) is commonly deregulated in a number of cancers. Through the screening of the microRNA expression profile in bladder cancer tissue and cell lines, we found that expression of miR-205 was significantly suppressed. In addition, the levels of miR-205 expression had a negative correlation with the degree of bladder cancer malignancy. However, the biological functions of miR-205 remained unclear. In this study, we have demonstrated that miR-205 had a role in the inhibition of proliferation, migration and invasion of bladder cancer cells. Moreover, we have identified cyclin J (CCNJ) gene, which is involved in cell cycle regulation, as a novel target for miR-205. Furthermore, a long non-coding RNA HOTAIR (HOX transcript antisense RNA) was observed to participate in the silencing of miR-205 in bladder cancer cells by breaking the balance of histone modification between H3K4me3 (histone H3 at lysine 4 methylation) and H3K27me3 on miR-205 promoter. This study elucidates an important role that miR-205 had in the regulation of proliferation, migration and invasion of bladder cancer cells, suggesting a potential therapeutic target for combating bladder cancer. PMID:26469956

  10. Identification and characterization of high affinity antisense PNAs for the human unr (upstream of N-ras) mRNA which is uniquely overexpressed in MCF-7 breast cancer cells.

    PubMed

    Fang, Huafeng; Yue, Xuan; Li, Xiaoxu; Taylor, John-Stephen

    2005-01-01

    We have recently shown that an MCF-7 tumor can be imaged in a mouse by PET with 64Cu-labeled Peptide nucleic acids (PNAs) tethered to the permeation peptide Lys4 that recognize the uniquely overexpressed and very abundant upstream of N-ras or N-ras related gene (unr mRNA) expressed in these cells. Herein we describe how the high affinity antisense PNAs to the unr mRNA were identified and characterized. First, antisense binding sites on the unr mRNA were mapped by an reverse transcriptase random oligonucleotide library (RT-ROL) method that we have improved, and by a serial analysis of antisense binding sites (SAABS) method that we have developed which is similar to another recently described method. The relative binding affinities of oligodeoxynucleotides (ODNs) complementary to the antisense binding sites were then qualitatively ranked by a new Dynabead-based dot blot assay. Dissociation constants for a subset of the ODNs were determined by a new Dynabead-based solution assay and were found to be 300 pM for the best binders in 1 M salt. PNAs corresponding to the ODNs with the highest affinities were synthesized with an N-terminal CysTyr and C-terminal Lys4 sequence. Dissociation constants of these hybrid PNAs were determined by the Dynabead-based solution assay to be about 10 pM for the highest affinity binders. PMID:16314303

  11. Tracking the down-regulation of folate receptor-α in cancer cells through target specific delivery of quantum dots coupled with antisense oligonucleotide and targeted peptide.

    PubMed

    Zhang, Ming-Zhen; Yu, Yong; Yu, Rong-Na; Wan, Min; Zhang, Rong-Ying; Zhao, Yuan-Di

    2013-12-20

    Based on the multivalent binding capability of streptavidin (SA) to biotin, a multifunctional quantum dot probe (QD-(AS-ODN+p160)) coupled with antisense oligonucleotide (AS-ODN) and peptide p160 is designed for real-time tracking of targeted delivery of AS-ODN and regulation of folate receptor-α (hFR-α) in MCF-7 breast cancer cells. Fluorescence spectra, capillary electrophoresis (CE) and dynamic light scattering (DLS) are used to characterize the conjugation of AS-ODN and p160 with quantum dots (QDs), DLS results confirm the well stability of the probe in aqueous media. Confocal imaging and quantitative flow cytometry show that QD-(AS-ODN+p160) is able to specifically target human breast cancer MCF-7 cells. Low temperature and ATP depletion treatments reveal the cellular uptake of QD-(AS-ODN+p160) is energy-dependent, and the effects of inhibition agents and co-localization imaging further confirm the endocytic pathway is mainly receptor-mediated. Transmission electron microscopy (TEM) shows the intracellular delivery and endosomal escape of QD probe along with incubation time extended. Two transfection concentrations of QD probe (10 nM and 50 nM) below half inhibitory concentration (IC50 ) value are chosen according to MTT assay. Real-time PCR shows at these two concentration cases the relative mRNA expression levels of hFR-α reduce to 72.5 ± 3.9% and 17.6 ± 1.0%, respectively. However, western blot and quantitative ELISA analysis show the expression level of hFR-α protein has a significant decrease only at 50 nM, indicating that gene silence is concentration-dependent. These results demonstrate that the QD-(AS-ODN+p160) probe not only achieves gene silence in a cell-specific manner but also achieves real-time tracking during AS-ODN intracellular delivery. PMID:23828664

  12. Synthesis, Improved Antisense Activity and Structural Rationale for the Divergent RNA Affinities of 3;#8242;-Fluoro Hexitol Nucleic Acid (FHNA and Ara-FHNA) Modified Oligonucleotides

    SciTech Connect

    Egli, Martin; Pallan, Pradeep S.; Allerson, Charles R.; Prakash, Thazha P.; Berdeja, Andres; Yu, Jinghua; Lee, Sam; Watt, Andrew; Gaus, Hans; Bhat, Balkrishen; Swayze, Eric E.; Seth, Punit P.

    2012-03-16

    The synthesis, biophysical, structural, and biological properties of both isomers of 3'-fluoro hexitol nucleic acid (FHNA and Ara-FHNA) modified oligonucleotides are reported. Synthesis of the FHNA and Ara-FHNA thymine phosphoramidites was efficiently accomplished starting from known sugar precursors. Optimal RNA affinities were observed with a 3'-fluorine atom and nucleobase in a trans-diaxial orientation. The Ara-FHNA analog with an equatorial fluorine was found to be destabilizing. However, the magnitude of destabilization was sequence-dependent. Thus, the loss of stability is sharply reduced when Ara-FHNA residues were inserted at pyrimidine-purine (Py-Pu) steps compared to placement within a stretch of pyrimidines (Py-Py). Crystal structures of A-type DNA duplexes modified with either monomer provide a rationalization for the opposing stability effects and point to a steric origin of the destabilization caused by the Ara-FHNA analog. The sequence dependent effect can be explained by the formation of an internucleotide C-F {hor_ellipsis} H-C pseudo hydrogen bond between F3' of Ara-FHNA and C8-H of the nucleobase from the 3'-adjacent adenosine that is absent at Py-Py steps. In animal experiments, FHNA-modified antisense oligonucleotides formulated in saline showed a potent downregulation of gene expression in liver tissue without producing hepatotoxicity. Our data establish FHNA as a useful modification for antisense therapeutics and also confirm the stabilizing influence of F(Py) {hor_ellipsis} H-C(Pu) pseudo hydrogen bonds in nucleic acid structures.

  13. Antisense versus proopiomelanocortin mRNA reduces vascular risk in a murine model of type-2 diabetes following stress exposure in early post-natal life.

    PubMed

    Loizzo, Alberto; Spampinato, Santi M; Fortuna, Andrea; Vella, Stefano; Fabi, Fulvia; Del Basso, Paola; Campana, Gabriele; Loizzo, Stefano

    2015-02-01

    Mechanisms of vascular complications in type-2 diabetes patients and animal models are matter of debate. We previously demonstrated that a double-stress model applied to male mice during nursing period produces enduring hyperfunction of endogenous opioid and adrenocorticotropin (ACTH)-corticosteroid systems, accompanied by type-2 diabetes-like alterations in adult animals. Administration of the opioid receptor antagonist naloxone, or of an antisense oligodeoxynucleotide versus proopiomelanocortin mRNA, capable to block the pro-opiomelanocortin-derived peptides β-endorphin and ACTH, selectively prevent these alterations. Here, we investigated alterations produced by our stress model on aorta endothelium-dependent relaxation and contractile responses. Mice, stressed during nursing period, showed in the adulthood hormonal and metabolic type-2 diabetes-like alterations, including hyperglycemia, increased body weight and increased plasma ACTH and corticosterone levels. Ex vivo isolated aorta rings, gathered from stressed mice, were less sensitive to noradrenaline-induced contractions versus controls. This effect was blocked by nitric-oxide synthase-inhibitor l-N(G)-nitroarginine added to bath organ solution. Aorta rings relaxation caused by acetylcholine was enhanced in stressed mice versus controls, but following treatment with the nitric-oxide donor sodium nitroprusside, concentration-relaxation curves in aorta from stressed groups were similar to controls. Therefore, vascular response alterations to physiologic-pharmacologic stimuli were apparently due to nitric-oxide hyperfunction-dependent mechanisms. Aorta functional alterations, and plasma stress hormones enhancement, were prevented in mice stressed and treated with antisense oligodeoxinucleotide, addressed to reduce ACTH- and corticosteroid-mediated hyperfunction. This study demonstrates the key role of ACTH-corticosteroid axis hyperfunction for the triggering of vascular conditions in male adult rodents

  14. Synthesis, improved antisense activity and structural rationale for the divergent RNA affinities of 3'-fluoro hexitol nucleic acid (FHNA and Ara-FHNA) modified oligonucleotides.

    PubMed

    Egli, Martin; Pallan, Pradeep S; Allerson, Charles R; Prakash, Thazha P; Berdeja, Andres; Yu, Jinghua; Lee, Sam; Watt, Andrew; Gaus, Hans; Bhat, Balkrishen; Swayze, Eric E; Seth, Punit P

    2011-10-19

    The synthesis, biophysical, structural, and biological properties of both isomers of 3'-fluoro hexitol nucleic acid (FHNA and Ara-FHNA) modified oligonucleotides are reported. Synthesis of the FHNA and Ara-FHNA thymine phosphoramidites was efficiently accomplished starting from known sugar precursors. Optimal RNA affinities were observed with a 3'-fluorine atom and nucleobase in a trans-diaxial orientation. The Ara-FHNA analog with an equatorial fluorine was found to be destabilizing. However, the magnitude of destabilization was sequence-dependent. Thus, the loss of stability is sharply reduced when Ara-FHNA residues were inserted at pyrimidine-purine (Py-Pu) steps compared to placement within a stretch of pyrimidines (Py-Py). Crystal structures of A-type DNA duplexes modified with either monomer provide a rationalization for the opposing stability effects and point to a steric origin of the destabilization caused by the Ara-FHNA analog. The sequence dependent effect can be explained by the formation of an internucleotide C-F···H-C pseudo hydrogen bond between F3' of Ara-FHNA and C8-H of the nucleobase from the 3'-adjacent adenosine that is absent at Py-Py steps. In animal experiments, FHNA-modified antisense oligonucleotides formulated in saline showed a potent downregulation of gene expression in liver tissue without producing hepatotoxicity. Our data establish FHNA as a useful modification for antisense therapeutics and also confirm the stabilizing influence of F(Py)···H-C(Pu) pseudo hydrogen bonds in nucleic acid structures. PMID:21919455

  15. Regulation of Pluripotency by RNA Binding Proteins

    PubMed Central

    Ye, Julia; Blelloch, Robert

    2015-01-01

    Establishment, maintenance, and exit from pluripotency require precise coordination of a cell’s molecular machinery. Substantial headway has been made in deciphering many aspects of this elaborate system, particularly with respect to epigenetics, transcription, and noncoding RNAs. Less attention has been paid to posttranscriptional regulatory processes such as alternative splicing, RNA processing and modification, nuclear export, regulation of transcript stability, and translation. Here, we introduce the RNA binding proteins that enable the posttranscriptional regulation of gene expression, summarizing current and ongoing research on their roles at different regulatory points and discussing how they help script the fate of pluripotent stem cells. PMID:25192462

  16. Estrogen Regulation of MicroRNA Expression

    PubMed Central

    Klinge, Carolyn M

    2009-01-01

    Women outlive men, but life expectancy is not influenced by hormone replacement (estrogen + progestin) therapy. Estrogens appear to protect brain, cardiovascular tissues, and bone from aging. Estrogens regulate genes directly through binding to estrogen receptors alpha and beta (ERα and ERβ) that are ligand-activated transcription factors and indirectly by activating plasma membrane-associated ER which, in turns, activates intracellular signaling cascades leading to altered gene expression. MicroRNAs (miRNAs) are short (19-25 nucleotides), naturally-occurring, non-coding RNA molecules that base-pair with the 3’ untranslated region of target mRNAs. This interaction either blocks translation of the mRNA or targets the mRNA transcript to be degraded. The human genome contains ~ 700-1,200 miRNAs. Aberrant patterns of miRNA expression are implicated in human diseases including breast cancer. Recent studies have identified miRNAs regulated by estrogens in human breast cancer cells, human endometrial stromal and myometrial smooth muscle cells, rat mammary gland, and mouse uterus. The decline of estradiol levels in postmenopausal women has been implicated in various age-associated disorders. The role of estrogen-regulated miRNA expression, the target genes of these miRNAs, and the role of miRNAs in aging has yet to be explored. PMID:19881910

  17. The role of ClC-3 in volume-activated chloride currents and volume regulation in bovine epithelial cells demonstrated by antisense inhibition

    PubMed Central

    Wang, Liwei; Chen, Lixin; Jacob, Tim J C

    2000-01-01

    A chloride current with mild outward rectification was induced in the native bovine non-pigmented ciliary epithelial (NPCE) cells by a 23 % hypotonic solution. The current showed no or little inactivation at depolarized steps. ATP blocked 88 and 61 % of the outward and inward components of the volume-activated chloride current (ICl,vol) with an IC50 of 5.3 and 9.6 mm, respectively. The volume-activated chloride current was decreased and the activation of the current was delayed by inhibiting endogenous ClC-3 expression using a ClC-3 antisense oligonucleotide. The inhibition of the current as a function of antisense concentration was asymptotic with a maximum about 60 %. The remaining current was probably not derived from ClC-3 and was inhibited by ATP. ClC-3 expression in the bovine NPCE cells was verified by immunofluorescence studies. ClC-3 immunofluorescence was distributed throughout the cells but with the predominant location within the nucleus. The expression of ClC-3 protein was diminished by the ClC-3 antisense oligonucleotide with the greatest diminution occurring in the nuclear region. The size of the volume-activated chloride current was positively correlated with the ClC-3 immunofluorescence level. Regulatory volume decrease of the NPCE cells was reduced by ClC-3 antisense oligonucleotide. We conclude that endogenous ClC-3 is associated with the volume-activated chloride current and is involved in cell volume regulation, but that it can only contribute towards a proportion of the current in NPCE cells. The nuclear predominance of ClC-3 immunofluorescence in NPCE cells, the absence of basal activity of chloride current and the marked pharmacological differences between IClC-3 and ICl,vol argue against ClC-3 being the only, or even the main, volume-activated chloride channel in NPCE cells. PMID:10747184

  18. The 5′-tail of antisense RNAII of pMV158 plays a critical role in binding to the target mRNA and in translation inhibition of repB

    PubMed Central

    López-Aguilar, Celeste; Romero-López, Cristina; Espinosa, Manuel; Berzal-Herranz, Alfredo; del Solar, Gloria

    2015-01-01

    Rolling-circle replication of streptococcal plasmid pMV158 is controlled by the concerted action of two trans-acting elements, namely transcriptional repressor CopG and antisense RNAII, which inhibit expression of the repB gene encoding the replication initiator protein. The pMV158-encoded antisense RNAII exerts its activity of replication control by inhibiting translation of the essential repB gene. RNAII is the smallest and simplest among the characterized antisense RNAs involved in control of plasmid replication. Structure analysis of RNAII revealed that it folds into an 8-bp-long stem containing a 1-nt bulge and closed by a 6-nt apical loop. This hairpin is flanked by a 17-nt-long single-stranded 5′-tail and an 8-nt-long 3′-terminal U-rich stretch. Here, the 3′ and 5′ regions of the 5′-tail of RNAII are shown to play a critical role in the binding to the target mRNA and in the inhibition of repB translation, respectively. In contrast, the apical loop of the single hairpin of RNAII plays a rather secondary role and the upper stem region hardly contributes to the binding or inhibition processes. The entire 5′-tail is required for efficient inhibition of repB translation, though only the 8-nt-long region adjacent to the hairpin seems to be essential for rapid binding to the mRNA. These results show that a “kissing” interaction involving base-pairing between complementary hairpin loops in RNAII and mRNA is not critical for efficient RNA/RNA binding or repB translation inhibition. A singular binding mechanism is envisaged whereby initial pairing between complementary single-stranded regions in the antisense and sense RNAs progresses upwards into the corresponding hairpin stems to form the intermolecular duplex. PMID:26175752

  19. Exploring RNA polymerase regulation by NMR spectroscopy

    PubMed Central

    Drögemüller, Johanna; Strauß, Martin; Schweimer, Kristian; Wöhrl, Birgitta M.; Knauer, Stefan H.; Rösch, Paul

    2015-01-01

    RNA synthesis is a central process in all organisms, with RNA polymerase (RNAP) as the key enzyme. Multisubunit RNAPs are evolutionary related and are tightly regulated by a multitude of transcription factors. Although Escherichia coli RNAP has been studied extensively, only little information is available about its dynamics and transient interactions. This information, however, are crucial for the complete understanding of transcription regulation in atomic detail. To study RNAP by NMR spectroscopy we developed a highly efficient procedure for the assembly of active RNAP from separately expressed subunits that allows specific labeling of the individual constituents. We recorded [1H,13C] correlation spectra of isoleucine, leucine, and valine methyl groups of complete RNAP and the separately labeled β’ subunit within reconstituted RNAP. We further produced all RNAP subunits individually, established experiments to determine which RNAP subunit a certain regulator binds to, and identified the β subunit to bind NusE. PMID:26043358

  20. Reversible RNA adenosine methylation in biological regulation

    PubMed Central

    Jia, Guifang; Fu, Ye; He, Chuan

    2012-01-01

    N6-methyladenosine (m6A) is a ubiquitous modification in messenger RNA (mRNA) and other RNAs across most eukaryotes. For many years, however, the exact functions of m6A were not clearly understood. The discovery that the fat mass and obesity associated protein (FTO) is an m6A demethylase indicates that this modification is reversible and dynamically regulated, suggesting it has regulatory roles. In addition, it has been shown that m6A affects cell fate decisions in yeast and plant development. Recent affinity-based m6A profiling in mouse and human cells further showed that this modification is a widespread mark in coding and non-coding RNA transcripts and is likely dynamically regulated throughout developmental processes. Therefore, reversible RNA methylation, analogous to reversible DNA and histone modifications, may affect gene expression and cell fate decisions by modulating multiple RNA-related cellular pathways, which potentially provides rapid responses to various cellular and environmental signals, including energy and nutrient availability in mammals. PMID:23218460

  1. Downregulation of yidC in Escherichia coli by Antisense RNA Expression Results in Sensitization to Antibacterial Essential Oils Eugenol and Carvacrol

    PubMed Central

    Patil, Supriya Deepak; Sharma, Rajnikant; Srivastava, Santosh; Navani, Naveen Kumar; Pathania, Ranjana

    2013-01-01

    Background The rising drug resistance in pathogenic bacteria and inefficiency of current antibiotics to meet clinical requirements has augmented the need to establish new and innovative approaches for antibacterial drug discovery involving identification of novel antibacterial targets and inhibitors. Being obligatory for bacterial growth, essential gene products are considered vital as drug targets. The bacterial protein YidC is highly conserved among pathogens and is essential for membrane protein insertion due to which it holds immense potential as a promising target for antibacterial therapy. Methods/Principal Findings The aim of this study was to explore the feasibility and efficacy of expressed antisense-mediated gene silencing for specific downregulation of yidC in Escherichia coli. We induced RNA silencing of yidC which resulted in impaired growth of the host cells. This was followed by a search for antibacterial compounds sensitizing the YidC depleted cells as they may act as inhibitors of the essential protein or its products. The present findings affirm that reduction of YidC synthesis results in bacterial growth retardation, which warrants the use of this enzyme as a viable target in search of novel antibacterial agents. Moreover, yidC antisense expression in E. coli resulted in sensitization to antibacterial essential oils eugenol and carvacrol. Fractional Inhibitory Concentration Indices (FICIs) point towards high level of synergy between yidC silencing and eugenol/carvacrol treatment. Finally, as there are no known YidC inhibitors, the RNA silencing approach applied in this study put forward rapid means to screen novel potential YidC inhibitors. Conclusions/Significance The present results suggest that YidC is a promising candidate target for screening antibacterial agents. High level of synergy reported here between yidC silencing and eugenol/carvacrol treatment is indicative of a potential antibacterial therapy. This is the first report indicating

  2. Regulation of functional KCNQ1OT1 lncRNA by β-catenin

    PubMed Central

    Sunamura, Naohiro; Ohira, Takahito; Kataoka, Miki; Inaoka, Daigo; Tanabe, Hideyuki; Nakayama, Yuji; Oshimura, Mitsuo; Kugoh, Hiroyuki

    2016-01-01

    Long noncoding RNAs (lncRNAs) have been implicated in many biological processes through epigenetic mechanisms. We previously reported that KCNQ1OT1, an imprinted antisense lncRNA in the human KCNQ1 locus on chromosome 11p15.5, is involved in cis-limited silencing within an imprinted KCNQ1 cluster. Furthermore, aberration of KCNQ1OT1 transcription was observed with a high frequency in colorectal cancers. However, the molecular mechanism of the transcriptional regulation and the functional role of KCNQ1OT1 in colorectal cancer remain unclear. Here, we show that the KCNQ1OT1 transcriptional level was significantly increased in human colorectal cancer cells in which β-catenin was excessively accumulated in the nucleus. Additionally, overexpression of β-catenin resulted in an increase in KCNQ1OT1 lncRNA-coated territory. On the other hand, knockdown of β-catenin resulted in significant decrease of KCNQ1OT1 lncRNA-coated territory and an increase in the mRNA expression of the SLC22A18 and PHLDA2 genes that are regulated by KCNQ1OT1. We showed that β-catenin can promote KCNQ1OT1 transcription through direct binding to the KCNQ1OT1 promoter. Our evidence indicates that β-catenin signaling may contribute to development of colorectal cancer by functioning as a novel lncRNA regulatory factor via direct targeting of KCNQ1OT1. PMID:26868975

  3. [Suppression of replication of swine parvoviral antisense RNA against the NS PPV gene in swine thyroid gland cells].

    PubMed

    Voskresenskaia, E P; Miroshnichenko, O I; Ponamareva, T I; Savich, O M; Tikhonenko, T I

    1993-01-01

    The possibility of suppression of porcine parvovirus (PPV) reproduction in the culture of thyroid gland cells of a swine that contain the integrated genes for asRNA against the nonstructural proteins of the virus has been studied. 10 cell lines with the asRNA genes have been obtained. The line with the maximal number of integrated gene copies was used to inflict with the parvovirus. The expression of asRNA in this cell line was shown to lead to 95% suppression of PPV replication as compared with the control cell line. PMID:8510680

  4. Reduction of Uroporphyrinogen Decarboxylase by Antisense RNA Expression Affects Activities of Other Enzymes Involved in Tetrapyrrole Biosynthesis and Leads to Light-Dependent Necrosis.

    PubMed Central

    Mock, H. P.; Grimm, B.

    1997-01-01

    We introduced a full-length cDNA sequence encoding tobacco (Nicotiana tabacum) uroporphyrinogen III decarboxylase (UROD; EC 4.1.1.37) in reverse orientation under the control of a cauliflower mosaic virus 35S promoter derivative into the tobacco genome to study the effects of deregulated UROD expression on tetrapyrrole biosynthesis. Transformants with reduced UROD activity were characterized by stunted plant growth and necrotic leaf lesions. Antisense RNA expression caused reduced UROD protein levels and reduced activity to 45% of wild type, which was correlated with the accumulation of uroporphyrin(ogen) and with the intensity of necrotic damage. Chlorophyll levels were only slightly reduced (up to 15%), indicating that the plants sustained cellular damage from accumulating photosensitive porphyrins rather than from chlorophyll deficiency. A 16-h light/8-h dark regime at high-light intensity stimulates the formation of leaf necrosis compared with a low-light or a 6-h high-light treatment. Transgenic plants grown at high light also showed inactivation of 5-aminolevulinate dehydratase and porphobilinogen deaminase, whereas the activity of coproporphyrinogen oxidase and the 5-aminolevulinate synthesizing capacity were not altered. We conclude that photooxidation of accumulating uroporphyrin(ogen) leads to the generation of oxygen species, which destabilizes other enzymes in the porphyrin metabolic pathway. This porphyrin-induced necrosis resembles the induction of cell death observed during pathogenesis and air pollution. PMID:12223662

  5. Repetitive elements regulate circular RNA biogenesis

    PubMed Central

    Wilusz, Jeremy E

    2015-01-01

    It was long assumed that eukaryotic precursor mRNAs (pre-mRNAs) are almost always spliced to generate a linear mRNA that is subsequently translated to produce a protein. However, it is now clear that thousands of protein-coding genes can be non-canonically spliced to produce circular noncoding RNAs, some of which are expressed at much higher levels than their associated linear mRNAs. How then does the splicing machinery decide whether to generate a linear mRNA or a circular RNA? Recent work has revealed that intronic repetitive elements, including sequences derived from transposons, are critical regulators of this decision. In most cases, circular RNA biogenesis appears to be initiated when complementary sequences from 2 different introns base pair to one another. This brings the splice sites from the intervening exon(s) into close proximity and facilitates the backsplicing event that generates the circular RNA. As many pre-mRNAs contain multiple intronic repeats, distinct circular transcripts can be produced depending on which repeats base pair to one another. Intronic repeats are thus critical regulatory sequences that control the functional output of their host genes, and potentially cause the functions of protein-coding genes to be highly divergent across species. PMID:26442181

  6. Subgenomic mRNA regulation by a distal RNA element in a (+)-strand RNA virus.

    PubMed Central

    Zhang, G; Slowinski, V; White, K A

    1999-01-01

    Subgenomic (sg) mRNAs are synthesized by (+)-strand RNA viruses to allow for efficient translation of products encoded 3' in their genomes. This strategy also provides a means for regulating the expression of such products via modulation of sg mRNA accumulation. We have studied the mechanism by which sg mRNAs levels are controlled in tomato bushy stunt virus, a small (+)-strand RNA virus which synthesizes two sg mRNAs during infections. Neither the viral capsid nor movement proteins were found to play any significant role in modulating the accumulation levels of either sg mRNA. Deletion analysis did, however, identify a 12-nt-long RNA sequence located approximately 1,000 nt upstream from the site of initiation of sg mRNA2 synthesis that was required specifically for accumulation of sg mRNA2. Further analysis revealed a potential base-pairing interaction between this sequence and a sequence located just 5' to the site of initiation for sg mRNA2 synthesis. Mutant genomes in which this interaction was either disrupted or maintained were analyzed and the results indicated a positive correlation between the predicted stability of the base-pairing interaction and the efficiency of sg mRNA2 accumulation. The functional significance of the long-distance interaction was further supported by phylogenetic sequence analysis which revealed conservation of base-pairing interactions of similar stability and relative position in the genomes of different tombusviruses. It is proposed that the upstream sequence represents a cis-acting RNA element which facilitates sg mRNA accumulation by promoting efficient synthesis of sg mRNA2 via a long-distance RNA-RNA interaction. PMID:10199571

  7. Regulating the Regulators: microRNA and Asthma

    PubMed Central

    2011-01-01

    One obstacle to developing an effective therapeutic strategy to treat or prevent asthma is that the fundamental causes of asthma are not totally understood. Asthma is thought to be a chronic TH2 immune-mediated inflammatory disease. Epigenetic changes are recognized to play a role in the initiation and maintenance of a TH2 response. MicroRNAs (miRNAs) are key epigenetic regulators of gene expression, and their expression is highly regulated, therefore, deregulation of miRNAs may play an important role in the pathogenesis of asthma. Profiling circulating miRNA might provide the highest specificity and sensitivity to diagnose asthma; similarly, correcting potential defects in the miRNA regulation network may lead to new therapeutic modalities to treat this disease. PMID:23282474

  8. Comparative Characterization of Hepatic Distribution and mRNA Reduction of Antisense Oligonucleotides Conjugated with Triantennary N-Acetyl Galactosamine and Lipophilic Ligands Targeting Apolipoprotein B.

    PubMed

    Watanabe, Ayahisa; Nakajima, Mado; Kasuya, Takeshi; Onishi, Reina; Kitade, Naohisa; Mayumi, Kei; Ikehara, Tatsuya; Kugimiya, Akira

    2016-05-01

    TriantennaryN-acetyl galactosamine (GalNAc, GN3) and lipophilic ligands such as cholesterol andα-tocopherol conjugations dramatically improve the distribution and efficacy of second-generation antisense oligonucleotides (ASOs) in the whole liver. To characterize ligands for delivery to liver cells based on pharmacokinetics and efficacy, we used a locked nucleic acid gapmer of ASO targeting apolipoprotein B as a model compound and evaluated the amount of ASO and apolipoprotein B mRNA in the whole liver, hepatocytes, and nonparenchymal (NP) cells as well as plasma total cholesterol after administration of ASO conjugated with these ligands to mice. Compared with unconjugated ASO, GN3 conjugation increased the amount (7-fold) and efficacy (more than 10-fold) of ASO in hepatocytes only and showed higher efficacy than the increased rate of the amount of ASO. On the other hand, lipophilic ligand conjugations led to increased delivery (3- to 5-fold) and efficacy (5-fold) of ASO to both hepatocytes and NP cells. GN3 and lipophilic ligand conjugations increased the area under the curve of ASOs and the pharmacodynamic duration but did not change the half-life in hepatocytes and NP cells compared with unconjugated ASO. In the liver, the phosphodiester bond between ASO and these ligands was promptly cleaved to liberate unconjugated ASO. These ligand conjugations reduced plasma total cholesterol compared with unconjugated ASO, although these ASOs were well tolerated with no elevation in plasma transaminases. These findings could facilitate ligand selection tailored to liver cells expressed in disease-related genes and could contribute to the discovery and development of RNA interference-based therapy. PMID:26907624

  9. APeg3: regulation of Peg3 through an evolutionarily conserved ncRNA

    PubMed Central

    Frey, Wesley D.

    2014-01-01

    Mammalian APeg3 is an antisense gene that is localized within the 3′-untranslated region of the imprinted gene, Peg3. APeg3 is expressed only in the vasopressinergic neurons of the hypothalamus, thus is predicted to play significant roles in this specific area of the brain. In the current study, we investigate the functions of APeg3 with comparative genomics and cell line-based functional approaches. The transcribed region of APeg3 displays high levels of sequence conservation among placental mammals, but without any obvious open reading frame, suggesting that APeg3 may have been selected as a ncRNA gene during eutherian evolution. This has been further supported by the detection of a conserved local RNA secondary structure within APeg3. RNA secondary structure analyses indicate a single conserved hairpin-loop structure towards the 5′ end of the transcript. The results from cell line-based transfection experiments demonstrate that APeg3 has the potential to down-regulate the transcription and protein levels of Peg3. The observed down-regulation by APeg3 is also somewhat orientation-independent. Overall, these results suggest that APeg3 has evolved as a ncRNA gene and controls the function of its sense gene Peg3 within specific neuronal cells. PMID:24582979

  10. Directional gene expression and antisense transcripts in sexual and asexual stages of Plasmodium falciparum

    PubMed Central

    2011-01-01

    Background It has been shown that nearly a quarter of the initial predicted gene models in the Plasmodium falciparum genome contain errors. Although there have been efforts to obtain complete cDNA sequences to correct the errors, the coverage of cDNA sequences on the predicted genes is still incomplete, and many gene models for those expressed in sexual or mosquito stages have not been validated. Antisense transcripts have widely been reported in P. falciparum; however, the extent and pattern of antisense transcripts in different developmental stages remain largely unknown. Results We have sequenced seven bidirectional libraries from ring, early and late trophozoite, schizont, gametocyte II, gametocyte V, and ookinete, and four strand-specific libraries from late trophozoite, schizont, gametocyte II, and gametocyte V of the 3D7 parasites. Alignment of the cDNA sequences to the 3D7 reference genome revealed stage-specific antisense transcripts and novel intron-exon splicing junctions. Sequencing of strand-specific cDNA libraries suggested that more genes are expressed in one direction in gametocyte than in schizont. Alternatively spliced genes, antisense transcripts, and stage-specific expressed genes were also characterized. Conclusions It is necessary to continue to sequence cDNA from different developmental stages, particularly those of non-erythrocytic stages. The presence of antisense transcripts in some gametocyte and ookinete genes suggests that these antisense RNA may play an important role in gene expression regulation and parasite development. Future gene expression studies should make use of directional cDNA libraries. Antisense transcripts may partly explain the observed discrepancy between levels of mRNA and protein expression. PMID:22129310

  11. Synthesis and antisense properties of fluoro cyclohexenyl nucleic acid (F-CeNA), a nuclease stable mimic of 2'-fluoro RNA.

    PubMed

    Seth, Punit P; Yu, Jinghua; Jazayeri, Ali; Pallan, Pradeep S; Allerson, Charles R; Østergaard, Michael E; Liu, Fengwu; Herdewijn, Piet; Egli, Martin; Swayze, Eric E

    2012-06-01

    -CeNA gapmer ASO showed similar RNA affinity but significantly improved activity compared to that of a sequence matched MOE ASO, thus establishing F-CeNA as a useful modification for antisense applications. PMID:22591005

  12. Antisense-mediated exon inclusion

    PubMed Central

    Hua, Yimin; Krainer, Adrian R

    2012-01-01

    Exon skipping induced by gene mutations is a common mechanism responsible for many genetic diseases. A practical approach to correct the aberrant splicing of defective genes is to use antisense oligonucleotides (ASOs). The recognition of splice sites and the regulation of splicing involve multiple positive or negative cis-acting elements and trans-acting factors. Base-pairing of ASOs to a negative element in a targeted pre-mRNA blocks the binding of splicing repressors to this cis-element and/or disrupts an unfavorable secondary structure; as a result, the ASO restores exon inclusion. For example, we have recently shown that appropriate 2’-O-(2-methoxyethyl) (MOE) phosphorothioate-modified ASOs can efficiently correct survival motor neuron 2 (SMN2) exon 7 splicing in a cell-free splicing assay, in cultured human cells—including patient fibroblasts—and in both peripheral tissues and the CNS of SMA mouse models. These ASOs are promising drug leads for SMA therapy. PMID:22454070

  13. Antisense inhibition of myoD expression in regenerating rat soleus muscle is followed by an increase in the mRNA levels of myoD, myf-5 and myogenin and by a retarded regeneration.

    PubMed

    Zádor, Erno; Bottka, Sándor; Wuytack, Frank

    2002-06-12

    It has been reported that muscles of myoD-/- mice present a lower potential to regenerate, but there are no reports on the effect of acute interference with myoD expression limited in space and time to only a particular regenerating muscle. Here we relied on antisense inhibition of this factor. Four different oligos were tested. The suppression of regeneration indices (the expression of desmin, the formation of myotubes and the initiation of endplates) was the most pronounced, with the oligomer targeting a region encompassing the translation start site of myoD. A mixed backbone phosphorothioate-phosphate diester oligo (200 microl at 20 microM) was still detectable in the muscles 1 h after its administration and reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that the level of the targeted 5' end of the myoD mRNA was selectively decreased. The level of myoD protein was also lowered. Four hours after the antisense treatment, when the oligos were no longer detectable, the myoD mRNA level was restored and 24 h later it exceeded controls together with that of myf-5 and myogenin. After 4 weeks, the antisense-treated soleus muscles were similar to the control-treated and the untreated regenerated soleus with respect to fiber types and motor endplates, however, they contained smaller fibers which reflected the asynchronity of regeneration. This shows that successfully targeted simple antisense oligonucleotides can be used as selective tools for inhibition of individual factors in studying the process of muscle regeneration. PMID:12063168

  14. MDM4 regulation by the let-7 miRNA family in the DNA damage response of glioma cells.

    PubMed

    Xie, Chen; Chen, Wei; Zhang, Mengdie; Cai, Qiuxian; Xu, Weiyi; Li, Xiaodi; Jiang, Songshan

    2015-07-01

    Despite extensive investigation into the role of let-7 miRNAs in pathological tumor processes, their involvement in the DNA damage response remains unclear. Here we show that most let-7 family members down-regulate MDM4 expression via binding to MDM4 mRNA at a conserved DNA sequence. Expression of exogenous let-7 miRNA mimics decreased MDM4 protein but not mRNA levels. Several DNA damage reagents increased let-7 expression, thereby decreasing MDM4 protein levels in glioma cells. Inhibition of endogenous let-7 with antisense RNAs rescued MDM4 protein levels with or without MG132, a proteasome-dependent degradation inhibitor. An MDM4 mutation identified in a glioma patient was associated with loss of the putative MDM4 target site. Therefore, let-7 binding to MDM4 is implicated in the DNA damage response. PMID:26028311

  15. Development of Antisense Drugs for Dyslipidemia.

    PubMed

    Yamamoto, Tsuyoshi; Wada, Fumito; Harada-Shiba, Mariko

    2016-09-01

    Abnormal elevation of low-density lipoprotein (LDL) and triglyceride-rich lipoproteins in plasma as well as dysfunction of anti-atherogenic high-density lipoprotein (HDL) have both been recognized as essential components of the pathogenesis of atherosclerosis and are classified as dyslipidemia. This review describes the arc of development of antisense oligonucleotides for the treatment of dyslipidemia. Chemically-armed antisense candidates can act on various kinds of transcripts, including mRNA and miRNA, via several different endogenous antisense mechanisms, and have exhibited potent systemic anti-dyslipidemic effects. Here, we present specific cutting-edge technologies have recently been brought into antisense strategies, and describe how they have improved the potency of antisense drugs in regard to pharmacokinetics and pharmacodynamics. In addition, we discuss perspectives for the use of armed antisense oligonucleotides as new clinical options for dyslipidemia, in the light of outcomes of recent clinical trials and safety concerns indicated by several clinical and preclinical studies. PMID:27466159

  16. Unmasking Upstream Gene Expression Regulators with miRNA-corrected mRNA Data

    PubMed Central

    Bollmann, Stephanie; Bu, Dengpan; Wang, Jiaqi; Bionaz, Massimo

    2015-01-01

    Expressed micro-RNA (miRNA) affects messenger RNA (mRNA) abundance, hindering the accuracy of upstream regulator analysis. Our objective was to provide an algorithm to correct such bias. Large mRNA and miRNA analyses were performed on RNA extracted from bovine liver and mammary tissue. Using four levels of target scores from TargetScan (all miRNA:mRNA target gene pairs or only the top 25%, 50%, or 75%). Using four levels of target scores from TargetScan (all miRNA:mRNA target gene pairs or only the top 25%, 50%, or 75%) and four levels of the magnitude of miRNA effect (ME) on mRNA expression (30%, 50%, 75%, and 83% mRNA reduction), we generated 17 different datasets (including the original dataset). For each dataset, we performed upstream regulator analysis using two bioinformatics tools. We detected an increased effect on the upstream regulator analysis with larger miRNA:mRNA pair bins and higher ME. The miRNA correction allowed identification of several upstream regulators not present in the analysis of the original dataset. Thus, the proposed algorithm improved the prediction of upstream regulators. PMID:27279737

  17. Undetected antisense tRNAs in mitochondrial genomes?

    PubMed Central

    2010-01-01

    Background The hypothesis that both mitochondrial (mt) complementary DNA strands of tRNA genes code for tRNAs (sense-antisense coding) is explored. This could explain why mt tRNA mutations are 6.5 times more frequently pathogenic than in other mt sequences. Antisense tRNA expression is plausible because tRNA punctuation signals mt sense RNA maturation: both sense and antisense tRNAs form secondary structures potentially signalling processing. Sense RNA maturation processes by default 11 antisense tRNAs neighbouring sense genes. If antisense tRNAs are expressed, processed antisense tRNAs should have adapted more for translational activity than unprocessed ones. Four tRNA properties are examined: antisense tRNA 5' and 3' end processing by sense RNA maturation and its accuracy, cloverleaf stability and misacylation potential. Results Processed antisense tRNAs align better with standard tRNA sequences with the same cognate than unprocessed antisense tRNAs, suggesting less misacylations. Misacylation increases with cloverleaf fragility and processing inaccuracy. Cloverleaf fragility, misacylation and processing accuracy of antisense tRNAs decrease with genome-wide usage of their predicted cognate amino acid. Conclusions These properties correlate as if they adaptively coevolved for translational activity by some antisense tRNAs, and to avoid such activity by other antisense tRNAs. Analyses also suggest previously unsuspected particularities of aminoacylation specificity in mt tRNAs: combinations of competition between tRNAs on tRNA synthetases with competition between tRNA synthetases on tRNAs determine specificities of tRNA amino acylations. The latter analyses show that alignment methods used to detect tRNA cognates yield relatively robust results, even when they apparently fail to detect the tRNA's cognate amino acid and indicate high misacylation potential. Reviewers This article was reviewed by Dr Juergen Brosius, Dr Anthony M Poole and Dr Andrei S Rodin (nominated

  18. Morpholino antisense oligo inhibits trans-splicing of pre-inositol 1,4,5-trisphosphate receptor mRNA of Trypanosoma cruzi and suppresses parasite growth and infectivity.

    PubMed

    Hashimoto, Muneaki; Nara, Takeshi; Mita, Toshihiro; Mikoshiba, Katsuhiko

    2016-06-01

    Morpholino antisense oligos (MAOs) are used to investigate physiological gene function by inhibiting gene translation or construction of specific alternative splicing variants by blocking cis-splicing. MAOs are attractive drug candidates for viral- and bacterial-infectious disease therapy because of properties such as in vivo stability and specificity to target genes. Recently, we showed that phosphorothioate antisense oligos against Trypanosoma cruzi inositol 1,4,5-trisphosphate receptor (TcIP3R) mRNA inhibit the parasite host cell infection. In the present study, we identified the spliced leader (SL) acceptor of pre-TcIP3R mRNA and synthesized MAO, which inhibited trans-splicing of the transcript (MAO-1). MAO-1 was found to inhibit the addition of SL-RNA to pre-TcIP3R mRNA by real-time RT-PCR analysis. Treatment of the parasites with MAO-1 significantly impaired the growth and infectivity into host cells. These results indicate that MAO-1 is a potential novel drug for Chagas disease and that MAOs inhibiting trans-splicing can be used to investigate the physiology of trypanosomal genes leading to the development of novel drugs. PMID:26680159

  19. MicroRNA-9 and MicroRNA-326 Regulate Human Dopamine D2 Receptor Expression, and the MicroRNA-mediated Expression Regulation Is Altered by a Genetic Variant*

    PubMed Central

    Shi, Sandra; Leites, Catherine; He, Deli; Schwartz, Daniel; Moy, Winton; Shi, Jianxin; Duan, Jubao

    2014-01-01

    The human dopamine receptor D2 (DRD2) has been implicated in the pathophysiology of schizophrenia and other neuropsychiatric disorders. Most antipsychotic drugs influence dopaminergic transmission through blocking dopamine receptors, primarily DRD2. We report here the post-transcriptional regulation of DRD2 expression by two brain-expressed microRNAs (miRs), miR-326 and miR-9, in an ex vivo mode, and show the relevance of miR-mediated DRD2 expression regulation in human dopaminergic neurons and in developing human brains. Both miRs targeted the 3′-UTR (untranslated region) of DRD2 in NT2 (neuron-committed teratocarcinoma, which endogenously expresses DRD2) and CHO (Chinese hamster ovary) cell lines, decreasing luciferase activity measured by a luciferase reporter gene assay. miR-326 overexpression reduced DRD2 mRNA and DRD2 receptor synthesis. Both antisense miR-326 and antisense miR-9 increased DRD2 protein abundance, suggesting an endogenous repression of DRD2 expression by both miRs. Furthermore, a genetic variant (rs1130354) within the DRD2 3′-UTR miR-targeting site interferes with miR-326-mediated repression of DRD2 expression. Finally, co-expression analysis identified an inverse correlation of DRD2 expression with both miR-326 and miR-9 in differentiating dopaminergic neurons derived from human induced pluripotent stem cells (iPSCs) and in developing human brain regions implicated in schizophrenia. Our study provides empirical evidence suggesting that miR-326 and miR-9 may regulate dopaminergic signaling, and miR-326 and miR-9 may be considered as potential drug targets for the treatment of disorders involving abnormal DRD2 function, such as schizophrenia. PMID:24675081

  20. Cloning of human Ca2+ homoeostasis endoplasmic reticulum protein (CHERP): regulated expression of antisense cDNA depletes CHERP, inhibits intracellular Ca2+ mobilization and decreases cell proliferation.

    PubMed Central

    Laplante, J M; O'Rourke, F; Lu, X; Fein, A; Olsen, A; Feinstein, M B

    2000-01-01

    A monoclonal antibody which blocks InsP(3)-induced Ca(2+) release from isolated endoplasmic reticulum was used to isolate a novel 4.0 kb cDNA from a human erythroleukaemia (HEL) cell cDNA expression library. A corresponding mRNA transcript of approx. 4.2 kb was present in all human cell lines and tissues examined, but cardiac and skeletal muscle had an additional transcript of 6.4 kb. The identification in GenBank(R) of homologous expressed sequence tags from many tissues and organisms suggests that the gene is ubiquitously expressed in higher eukaryotes. The gene was mapped to human chromosome 19p13.1. The cDNA predicts a 100 kDa protein, designated Ca(2+) homoeostasis endoplasmic reticulum protein (CHERP), with two putative transmembrane domains, multiple consensus phosphorylation sites, a polyglutamine tract of 12 repeats and regions of imperfect tryptophan and histadine octa- and nona-peptide repeats. In vitro translation of the full-length cDNA produced proteins of M(r) 128000 and 100000, corresponding to protein bands detected by Western blotting of many cell types. CHERP was co-localized in HEL cells with the InsP(3) receptor by two-colour immunofluorescence. Transfection of HEL cells with antisense cDNA led to an 80% decline in CHERP within 5 days of antisense induction, with markedly decreased intracellular Ca(2+) mobilization by thrombin, decreased DNA synthesis and growth arrest, indicating that the protein has an important function in Ca(2+) homoeostasis, growth and proliferation. PMID:10794731

  1. Voltage-gated calcium channel and antisense oligonucleotides thereto

    NASA Technical Reports Server (NTRS)

    Hruska, Keith A. (Inventor); Friedman, Peter A. (Inventor); Barry, Elizabeth L. R. (Inventor); Duncan, Randall L. (Inventor)

    1998-01-01

    An antisense oligonucleotide of 10 to 35 nucleotides in length that can hybridize with a region of the .alpha..sub.1 subunit of the SA-Cat channel gene DNA or mRNA is provided, together with pharmaceutical compositions containing and methods utilizing such antisense oligonucleotide.

  2. Antisense oligonucleotides as therapeutics for malignant diseases.

    PubMed

    Ho, P T; Parkinson, D R

    1997-04-01

    The continued progress in our understanding of the biology of neoplasia and in the identification, cloning, and sequencing of genes critical to tumor cell function permits the exploitation of this information to develop specific agents that may directly modulate the function of these genes or their protein products. Antisense oligonucleotides are being investigated as a potential therapeutic modality that takes direct advantage of molecular sequencing. The antisense approach uses short oligonucleotides designed to hybridize to a target mRNA transcript through Watson-Crick base pairing. The formation of this oligonucleotide: RNA heteroduplex results in mRNA inactivation and consequent inhibition of synthesis of the protein product. A fundamental attraction of the antisense approach is that this method potentially may be applied to any gene product, in theory, for the treatment of malignant and non-malignant diseases. However, this simple and attractive model has proven to be much more complex in practice. A number of important challenges in the preclinical development of antisense oligonucleotides have been identified, including stability, sequence length, cellular uptake, target sequence selection, appropriate negative controls, oligonucleotide: protein interactions, and cost of manufacture. Although the biological activity of an oligonucleotide against its molecular target is theoretically sequence-dependent, the animal pharmacokinetics and toxicology of phosphorothioate analogues directed against vastly disparate gene products appear relatively non-sequence-specific. In oncology, a number of clinical trials have been initiated with antisense oligonucleotides directed against molecular targets including: p53; bcl-2; raf kinase; protein kinase C-alpha; c-myb. The experience gained from these early clinical trials will be applicable to the next generation of antisense agents in development. These may include molecules with novel backbones or other structural

  3. Identification of alternative splicing regulators by RNA interference in Drosophila

    PubMed Central

    Park, Jung W.; Parisky, Katherine; Celotto, Alicia M.; Reenan, Robert A.; Graveley, Brenton R.

    2004-01-01

    Alternative splicing is thought to be regulated by nonspliceosomal RNA binding proteins that modulate the association of core components of the spliceosome with the pre-mRNA. Although the majority of metazoan genes encode pre-mRNAs that are alternatively spliced, remarkably few splicing regulators are currently known. Here, we used RNA interference to examine the role of >70% of the Drosophila RNA-binding proteins in regulating alternative splicing. We identified 47 proteins as splicing regulators, 26 of which have not previously been implicated in alternative splicing. Many of the regulators we identified are nonspliceosomal RNA-binding proteins. However, our screen unexpectedly revealed that altering the concentration of certain core components of the spliceosome specifically modulates alternative splicing. These results significantly expand the number of known splicing regulators and reveal an extraordinary richness in the mechanisms that regulate alternative splicing. PMID:15492211

  4. Exon-centric regulation of ATM expression is population-dependent and amenable to antisense modification by pseudoexon targeting

    PubMed Central

    Kralovicova, Jana; Knut, Marcin; Cross, Nicholas C. P.; Vorechovsky, Igor

    2016-01-01

    ATM is an important cancer susceptibility gene that encodes a critical apical kinase of the DNA damage response (DDR) pathway. We show that a key nonsense-mediated RNA decay switch exon (NSE) in ATM is repressed by U2AF, PUF60 and hnRNPA1. The NSE activation was haplotype-specific and was most promoted by cytosine at rs609621 in the NSE 3′ splice-site (3′ss), which is predominant in high cancer risk populations. NSE levels were deregulated in leukemias and were influenced by the identity of U2AF35 residue 34. We also identify splice-switching oligonucleotides (SSOs) that exploit competition of adjacent pseudoexons to modulate NSE levels. The U2AF-regulated exon usage in the ATM signalling pathway was centred on the MRN/ATM-CHEK2-CDC25-cdc2/cyclin-B axis and preferentially involved transcripts implicated in cancer-associated gene fusions and chromosomal translocations. These results reveal important links between 3′ss control and ATM-dependent responses to double-strand DNA breaks, demonstrate functional plasticity of intronic variants and illustrate versatility of intronic SSOs that target pseudo-3′ss to modify gene expression. PMID:26732650

  5. Antisense approaches in prostate cancer.

    PubMed

    Chi, Kim N; Gleave, Martin E

    2004-06-01

    Patients with hormone refractory prostate cancer have limited treatment options and new therapies are urgently needed. Advances in the understanding of the molecular mechanisms implicated in prostate cancer progression have identified many potential therapeutic gene targets that are involved in apoptosis, growth factors, cell signalling and the androgen receptor (AR). Antisense oligonucleotides are short sequences of synthetic modified DNA that are designed to be complimentary to a selected gene's mRNA and thereby specifically inhibit expression of that gene. The antisense approach continues to hold promise as a therapeutic modality to target genes involved in cancer progression, especially those in which the gene products are not amenable to small molecule inhibition or antibodies. The current status and future direction of a number of antisense oligonucleotides targeting several genes, including BCL-2, BCL-XL, clusterin, the inhibitors of apoptosis (IAP) family, MDM2, protein kinase C-alpha, c-raf, insulin-like growth factor binding proteins and the AR, that have potential clinical use in prostate cancer are reviewed. PMID:15174974

  6. Antisense Therapy in Neurology

    PubMed Central

    Lee, Joshua J.A.; Yokota, Toshifumi

    2013-01-01

    Antisense therapy is an approach to fighting diseases using short DNA-like molecules called antisense oligonucleotides. Recently, antisense therapy has emerged as an exciting and promising strategy for the treatment of various neurodegenerative and neuromuscular disorders. Previous and ongoing pre-clinical and clinical trials have provided encouraging early results. Spinal muscular atrophy (SMA), Huntington’s disease (HD), amyotrophic lateral sclerosis (ALS), Duchenne muscular dystrophy (DMD), Fukuyama congenital muscular dystrophy (FCMD), dysferlinopathy (including limb-girdle muscular dystrophy 2B; LGMD2B, Miyoshi myopathy; MM, and distal myopathy with anterior tibial onset; DMAT), and myotonic dystrophy (DM) are all reported to be promising targets for antisense therapy. This paper focuses on the current progress of antisense therapies in neurology. PMID:25562650

  7. Protein-coding cis-natural antisense transcripts have high and broad expression in Arabidopsis.

    PubMed

    Zhan, Shuhua; Lukens, Lewis

    2013-04-01

    Pairs of genes within eukaryotic genomes are often located on opposite DNA strands such that transcription generates cis-natural sense antisense transcripts (cis-NATs). This orientation of genes has been associated with the biogenesis of splice variants and natural antisense small RNAs. Here, in an analysis of currently available data, we report that within Arabidopsis (Arabidopsis thaliana), protein-coding cis-NATs are also characterized by high abundance, high coexpression, and broad expression. Our results suggest that a permissive chromatin environment may have led to the proximity of these genes. Compared with other genes, cis-NAT-encoding genes have enriched low-nucleosome-density regions, high levels of histone H3 lysine-9 acetylation, and low levels of H3 lysine-27 trimethylation. Promoters associated with broadly expressed genes are preferentially found in the 5' regulatory sequences of cis-NAT-encoding genes. Our results further suggest that natural antisense small RNA production from cis-NATs is limited. Small RNAs sequenced from natural antisense small RNA biogenesis mutants including dcl1, dcl2, dcl3, and rdr6 map to cis-NATs as frequently as small RNAs sequenced from wild-type plants. Future work will investigate if the positive transcriptional regulation of overlapping protein-coding genes contributes to the prevalence of these genes within other eukaryotic genomes. PMID:23457227

  8. New methods as alternative or corrective measures for the pitfalls and artifacts of reverse transcription and polymerase chain reactions (RT-PCR) in cloning chimeric or antisense-accompanied RNA

    PubMed Central

    Yuan, Chengfu; Liu, Yongming; Yang, Min; Liao, D. Joshua

    2013-01-01

    We established new methods for cloning cDNA ends that start with reverse transcription (RT) and soon proceed with the synthesis of the second cDNA strand, avoiding manipulations of fragile RNA. Our 3′-end cloning method does not involve poly-dT primers and polymerase chain reactions (PCR), is low in efficiency but high in fidelity and can clone those RNAs without a poly-A tail. We also established a cDNA protection assay to supersede RNA protection assay. The protected cDNA can be amplified, cloned and sequenced, enhancing sensitivity and fidelity. We report that RT product using gene-specific primer (GSP) cannot be gene- or strand-specific because RNA sample contains endogenous random primers (ERP). The gene-specificity may be improved by adding a linker sequence at the 5′-end of the GSP to prime RT and using the linker as a primer in the ensuing PCR. The strand-specificity may be improved by using strand-specific DNA oligos in our protection assay. The CDK4 mRNA and TSPAN31 mRNA are transcribed from the opposite DNA strands and overlap at their 3′ ends. Using this relationship as a model, we found that the overlapped sequence might serve as a primer with its antisense as the template to create a wrong-template extension in RT or PCR. We infer that two unrelated RNAs or cDNAs overlapping at the 5′- or 3′-end might create a spurious chimera in this way, and many chimeras with a homologous sequence may be such artifacts. The ERP and overlapping antisense together set complex pitfalls, which one should be aware of. PMID:23618925

  9. NAMPT regulates senescence, proliferation, and migration of endothelial progenitor cells through the SIRT1 AS lncRNA/miR-22/SIRT1 pathway.

    PubMed

    Ming, Guang-Feng; Wu, Kai; Hu, Kai; Chen, Yao; Xiao, Jian

    2016-09-23

    The importance of endothelial progenitor cells (EPCs) in cardiovascular diseases has been demonstrated by numerous studies. Previous studies have shown that Nicotinamide phosphoribosyltransferase (NAMPT) plays a role in EPC development by regulating Sirtuin 1 (SIRT1), but the specific mechanism has not yet been elucidated. After stimulating EPCs with NAMPT, expression of SIRT1 and SIRT1 antisense long non-coding RNA (AS lncRNA) was upregulated. Upon transfection of an SIRT1 AS lncRNA overexpression vector into EPCs, SIRT1 expression was upregulated. Upon transfection of a small interfering RNA (siRNA) that targets SIRT1 AS lncRNA along with NAMPT, SIRT1 AS lncRNA was downregulated and NAMPT-induced SIRT1 expression was reduced. We used software analyses and a dual-luciferase reporter assay to demonstrate that microRNA (miR)-22 regulated SIRT1 and SIRT1 AS lncRNA. Our data suggest that SIRT1 AS lncRNA relieves miR-22-induced SIRT1 downregulation by competitively sponging miR-22. By measuring EPC senescence, proliferation, and migration, we found that NAMPT inhibited EPC senescence through an SIRT1 AS lncRNA/miR-22/SIRT1 pathway and promoted EPC proliferation and migration. These findings provide a new theoretical basis for the prevention and treatment of atherosclerosis (AS) and other cardiovascular diseases. PMID:27569277

  10. SUMOylation of TARBP2 regulates miRNA/siRNA efficiency.

    PubMed

    Chen, Cheng; Zhu, Changhong; Huang, Jian; Zhao, Xian; Deng, Rong; Zhang, Hailong; Dou, Jinzhuo; Chen, Qin; Xu, Ming; Yuan, Haihua; Wang, Yanli; Yu, Jianxiu

    2015-01-01

    Small RNA-induced gene silencing is essential for post-transcriptional regulation of gene expression; however, it remains unclear how miRNA/siRNA efficiency is regulated. Here we show that TARBP2 is SUMOylated at K52, which can be enhanced by its phosphorylation. This modification can stabilize TARBP2 via repressing its K(48)-linked ubiquitination. We find that TARBP2 SUMOylation does not influence the overall production of mature miRNAs, but it regulates miRNA/siRNA efficiency. SUMOylated TARBP2 recruits Ago2 to constitute the RNA-induced silencing complex (RISC)-loading complex (RLC), and simultaneously promotes more pre-miRNAs to load into the RLC. Consequently, Ago2 is stabilized and miRNAs/siRNAs bound by TARBP2/Dicer is effectively transferred to Ago2. Thus, these processes lead to the formation of the effective RISC for RNA interference (RNAi). Collectively, our data suggest that SUMOylation of TARBP2 is required for regulating miRNA/siRNA efficiency, which is a general mechanism of miRNA/siRNA regulation. PMID:26582366

  11. SUMOylation of TARBP2 regulates miRNA/siRNA efficiency

    PubMed Central

    Chen, Cheng; Zhu, Changhong; Huang, Jian; Zhao, Xian; Deng, Rong; Zhang, Hailong; Dou, Jinzhuo; Chen, Qin; Xu, Ming; Yuan, Haihua; Wang, Yanli; Yu, Jianxiu

    2015-01-01

    Small RNA-induced gene silencing is essential for post-transcriptional regulation of gene expression; however, it remains unclear how miRNA/siRNA efficiency is regulated. Here we show that TARBP2 is SUMOylated at K52, which can be enhanced by its phosphorylation. This modification can stabilize TARBP2 via repressing its K48-linked ubiquitination. We find that TARBP2 SUMOylation does not influence the overall production of mature miRNAs, but it regulates miRNA/siRNA efficiency. SUMOylated TARBP2 recruits Ago2 to constitute the RNA-induced silencing complex (RISC)-loading complex (RLC), and simultaneously promotes more pre-miRNAs to load into the RLC. Consequently, Ago2 is stabilized and miRNAs/siRNAs bound by TARBP2/Dicer is effectively transferred to Ago2. Thus, these processes lead to the formation of the effective RISC for RNA interference (RNAi). Collectively, our data suggest that SUMOylation of TARBP2 is required for regulating miRNA/siRNA efficiency, which is a general mechanism of miRNA/siRNA regulation. PMID:26582366

  12. Identifying miRNA/mRNA negative regulation pairs in colorectal cancer

    PubMed Central

    Zhou, Xile; Xu, Xiangming; Wang, Jinhai; Lin, Jianjiang; Chen, Wenbin

    2015-01-01

    Although considerable progress has been made in the molecular biology of Colorectal cancer (CRC), novel approaches are still required to uncover the detailed molecular mechanism of CRC. We aim to explore the potential negatively regulated miRNA-mRNA pairs and investigate their regulatory roles so as to elaborate the potential roles of the critical proteins in the signaling pathways enriched by the differential target genes of negatively regulated miRNA in CRC. Firstly, the differential miRNA-mRNA pairs were selected, followed by pairs of miRNA and their target genes. The obtained relationships were subjected to do functional enrichment analysis and those enriched in CRC pathways were chose to further construct a protein interaction network. Finally, we analyzed the regulatory roles of these relationships and constructed a regulatory network of negatively regulated miRNA and mRNA relationships. A total of 372 pairs of miRNA-mRNA were found and 108 target genes of miRNA were obtained. Three miRNAs including hsa-mir-23b, hsa-mir-365-1 and hsa-mir-365-2 showed significant influence on prognosis of CRC patients. To conclude, the miRNA/mRNA deregulations pairs identified in this study have high potentials to be further applied in diagnosis and treatment of CRC. PMID:26269151

  13. Antisense oligonucleotides bound in the polysaccharide complex and the enhanced antisense effect due to the low hydrolysis.

    PubMed

    Mizu, Masami; Koumoto, Kazuya; Anada, Takahisa; Sakurai, Kazuo; Shinkai, Seiji

    2004-07-01

    Schizophyllan is a beta-(1-->3)-D-glucan and can form a novel complex with some single-chains of DNAs. As the preceding paper revealed, the polynucleotide bound in the complex is more stable to nuclease-mediated hydrolysis than the polynucleotide itself (i.e., naked polynucleotide). This paper examined possibility to apply this complex to an antisense DNA carrier, using an in vitro (cell-free) transcription/translation assay. In this assay, we used a plasmid DNA coding a green fluorescence protein (GFP) and an antisense DNA designed to hybridize the ribosome-binding site in the GFP-coded mRNA. When the antisense DNA was administered as the complex, a lower GFP expression efficiency (or higher antisense effect) is observed over naked DNA. This is because the antisense DNA in the complex is protected from the attack of deoxyribonuclease. When exonuclease I, which specifically hydrolyzes single DNA chains, was present in the GEP assay system, the antisense effect was not changed for the complex while being weakened in the naked antisense DNA system. These results imply that the exonuclease I cannot hydrolyze the antisense DNA in the complex, while it can hydrolyze naked DNA to reduce its antisense effect. PMID:14967546

  14. Circular RNA Expression: Its Potential Regulation and Function

    PubMed Central

    Salzman, Julia

    2016-01-01

    In 2012, a new feature of eukaryotic gene expression emerged: ubiquitous expression of circular RNA (circRNA) from genes traditionally thought to express messenger or linear noncoding (nc)RNA only. CircRNAs are covalently closed, circular RNA molecules that typically comprise exonic sequences and are spliced at canonical splice sites. This feature of gene expression was first recognized in humans and mouse, but it quickly emerged that it was common across essentially all eukaryotes studied by molecular biologists. CircRNA abundance, and even which alternatively spliced circRNA isoforms are expressed, varies by cell type and can exceed the abundance of the traditional linear mRNA or ncRNA transcript. CircRNAs are enriched in the brain and increase in abundance during fetal development. Together, these features raise fundamental questions regarding the regulation of circRNA in cis and in trans, and its function. PMID:27050930

  15. Circular RNA Expression: Its Potential Regulation and Function.

    PubMed

    Salzman, Julia

    2016-05-01

    In 2012, a new feature of eukaryotic gene expression emerged: ubiquitous expression of circular RNA (circRNA) from genes traditionally thought to express messenger or linear noncoding (nc)RNA only. CircRNAs are covalently closed, circular RNA molecules that typically comprise exonic sequences and are spliced at canonical splice sites. This feature of gene expression was first recognized in humans and mouse, but it quickly emerged that it was common across essentially all eukaryotes studied by molecular biologists. CircRNA abundance, and even which alternatively spliced circRNA isoforms are expressed, varies by cell type and can exceed the abundance of the traditional linear mRNA or ncRNA transcript. CircRNAs are enriched in the brain and increase in abundance during fetal development. Together, these features raise fundamental questions regarding the regulation of circRNA in cis and in trans, and its function. PMID:27050930

  16. Drosha Regulates Gene Expression Independently of RNA Cleavage Function

    PubMed Central

    Gromak, Natalia; Dienstbier, Martin; Macias, Sara; Plass, Mireya; Eyras, Eduardo; Cáceres, Javier F.; Proudfoot, Nicholas J.

    2013-01-01

    Summary Drosha is the main RNase III-like enzyme involved in the process of microRNA (miRNA) biogenesis in the nucleus. Using whole-genome ChIP-on-chip analysis, we demonstrate that, in addition to miRNA sequences, Drosha specifically binds promoter-proximal regions of many human genes in a transcription-dependent manner. This binding is not associated with miRNA production or RNA cleavage. Drosha knockdown in HeLa cells downregulated nascent gene transcription, resulting in a reduction of polyadenylated mRNA produced from these gene regions. Furthermore, we show that this function of Drosha is dependent on its N-terminal protein-interaction domain, which associates with the RNA-binding protein CBP80 and RNA Polymerase II. Consequently, we uncover a previously unsuspected RNA cleavage-independent function of Drosha in the regulation of human gene expression. PMID:24360955

  17. LncRNA Khps1 Regulates Expression of the Proto-oncogene SPHK1 via Triplex-Mediated Changes in Chromatin Structure.

    PubMed

    Postepska-Igielska, Anna; Giwojna, Alena; Gasri-Plotnitsky, Lital; Schmitt, Nina; Dold, Annabelle; Ginsberg, Doron; Grummt, Ingrid

    2015-11-19

    Although thousands of long noncoding RNAs (lncRNAs) have been discovered, very little is known about their mode of action. Here we functionally characterize an E2F1-regulated lncRNA named Khps1, which is transcribed in antisense orientation to the proto-oncogene SPHK1. Khps1 activates SPHK1 expression by recruiting the histone acetyltransferase p300/CBP to the SPHK1 promoter, which leads to local changes of the chromatin structure that ensures E2F1 binding and enhances transcription. Mechanistically, this is achieved by direct association of Khps1 with a homopurine stretch upstream of the transcription start site of SPHK1, which forms a DNA-RNA triplex that anchors the lncRNA and associated effector proteins to the gene promoter. The results reveal an lncRNA- and E2F1-driven regulatory loop in which E2F1-dependent induction of antisense RNA leads to changes in chromatin structure, facilitating E2F1-dependent expression of SPHK1 and restriction of E2F1-induced apoptosis. PMID:26590717

  18. Does everything now make (anti)sense?

    PubMed

    Timmons, J A; Good, L

    2006-12-01

    The data generated by the FANTOM (Functional Annotation of Mouse) consortium, Compugen and Affymetrix have collectively provided evidence that most of the mammalian genomes are actively transcribed. The emergence of an antisense RNA world brings new practical complexities to the study and detection of gene expression. However, we also need to address the fundamental questions regarding the functional importance of these molecules. In this brief paper, we focus on non-coding natural antisense transcription, as it appears to be a potentially powerful mechanism for extending the complexity of the protein coding genome, which is currently unable to explain inter-species diversification. PMID:17073772

  19. A Universal Positive-Negative Selection System for Gene Targeting in Plants Combining an Antibiotic Resistance Gene and Its Antisense RNA.

    PubMed

    Nishizawa-Yokoi, Ayako; Nonaka, Satoko; Osakabe, Keishi; Saika, Hiroaki; Toki, Seiichi

    2015-09-01

    Gene targeting (GT) is a useful technology for accurate genome engineering in plants. A reproducible approach based on a positive-negative selection system using hygromycin resistance and the diphtheria toxin A subunit gene as positive and negative selection markers, respectively, is now available. However, to date, this selection system has been applied exclusively in rice (Oryza sativa). To establish a universally applicable positive-negative GT system in plants, we designed a selection system using a combination of neomycin phosphotransferaseII (nptII) and an antisense nptII construct. The concomitant transcription of both sense and antisense nptII suppresses significantly the level of expression of the sense nptII gene, and transgenic calli and plants become sensitive to the antibiotic geneticin. In addition, we were able to utilize the sense nptII gene as a positive selection marker and the antisense nptII construct as a negative selection marker for knockout of the endogenous rice genes Waxy and 33-kD globulin through GT, although negative selection with this system is relatively less efficient compared with diphtheria toxin A subunit. The approach developed here, with some additional improvements, could be applied as a universal selection system for the enrichment of GT cells in several plant species. PMID:26143254

  20. Intragenic pausing and anti-sense transcription within the murine c-myc locus.

    PubMed Central

    Nepveu, A; Marcu, K B

    1986-01-01

    We present a detailed analysis of strand-specific transcription in different regions of the murine c-myc locus. In normal and transformed cell lines, RNA polymerase II directed transcription occurs in the sense and anti-sense direction. Three noncontiguous regions show a high level of transcription in the anti-sense orientation: upstream of the first exon, within the first intron and in the 3' part of the gene (intron 2 and exon 3). In a cell line carrying a c-myc amplification (54c12), anti-sense transcription is not uniformly increased throughout the locus and is differentially affected by inhibition of protein synthesis. These results suggest that anti-sense transcription in various parts of the locus is independently regulated. In the sense orientation, transcriptional activity is higher in the first exon than in the rest of the gene indicating that transcription pauses near the 3' end of the first exon. The extent of this intragenic pausing varies among different cell lines and is most severe in cells with a c-myc amplification. Transcription initiation and pausing are both negatively regulated by labile proteins. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. PMID:3024965

  1. The Pokeweed Leaf mRNA Transcriptome and Its Regulation by Jasmonic Acid

    PubMed Central

    Neller, Kira C. M.; Klenov, Alexander; Hudak, Katalin A.

    2016-01-01

    The American pokeweed plant, Phytolacca americana, is recognized for synthesizing pokeweed antiviral protein (PAP), a ribosome inactivating protein (RIP) that inhibits the replication of several plant and animal viruses. The plant is also a heavy metal accumulator with applications in soil remediation. However, little is known about pokeweed stress responses, as large-scale sequencing projects have not been performed for this species. Here, we sequenced the mRNA transcriptome of pokeweed in the presence and absence of jasmonic acid (JA), a hormone mediating plant defense. Trinity-based de novo assembly of mRNA from leaf tissue and BLASTx homology searches against public sequence databases resulted in the annotation of 59 096 transcripts. Differential expression analysis identified JA-responsive genes that may be involved in defense against pathogen infection and herbivory. We confirmed the existence of several PAP isoforms and cloned a potentially novel isoform of PAP. Expression analysis indicated that PAP isoforms are differentially responsive to JA, perhaps indicating specialized roles within the plant. Finally, we identified 52 305 natural antisense transcript pairs, four of which comprised PAP isoforms, suggesting a novel form of RIP gene regulation. This transcriptome-wide study of a Phytolaccaceae family member provides a source of new genes that may be involved in stress tolerance in this plant. The sequences generated in our study have been deposited in the SRA database under project # SRP069141. PMID:27014307

  2. Is the Efficiency of RNA Silencing Evolutionarily Regulated?

    PubMed Central

    Ui-Tei, Kumiko

    2016-01-01

    Small interfering RNAs (siRNAs) and microRNAs (miRNAs) regulate gene expression in a sequence-specific manner. Genes with partial complementarity to siRNA/miRNA sequences in their 3′-untranslated regions (UTRs) are suppressed by a mechanism referred to as the siRNA off-target effect or miRNA-mediated RNA silencing. However, the determinants of such RNA silencing efficiency are poorly understood. Previously, I and co-workers reported that the efficiency of RNA silencing is strongly correlated with the thermodynamic stability of base pairing in the duplex formed within an siRNA/miRNA and between the seed region and its target mRNA. In this review, I first summarize our previous studies that identified the thermodynamic parameter to estimate the silencing efficiency using the calculated base pairing stability: siRNAs downregulate the expression of off-target genes depending on the stability of binding between the siRNA seed region (nucleotides 2–8) and off-target mRNAs, and miRNAs downregulate target mRNA expression depending on the stability of the duplex formed between the 5′ terminus of the miRNA and its target mRNA. I further discuss the possibility that such thermodynamic features of silencing efficiency may have arisen during evolution with increasing body temperature in various organisms. PMID:27187367

  3. Is the Efficiency of RNA Silencing Evolutionarily Regulated?

    PubMed

    Ui-Tei, Kumiko

    2016-01-01

    Small interfering RNAs (siRNAs) and microRNAs (miRNAs) regulate gene expression in a sequence-specific manner. Genes with partial complementarity to siRNA/miRNA sequences in their 3'-untranslated regions (UTRs) are suppressed by a mechanism referred to as the siRNA off-target effect or miRNA-mediated RNA silencing. However, the determinants of such RNA silencing efficiency are poorly understood. Previously, I and co-workers reported that the efficiency of RNA silencing is strongly correlated with the thermodynamic stability of base pairing in the duplex formed within an siRNA/miRNA and between the seed region and its target mRNA. In this review, I first summarize our previous studies that identified the thermodynamic parameter to estimate the silencing efficiency using the calculated base pairing stability: siRNAs downregulate the expression of off-target genes depending on the stability of binding between the siRNA seed region (nucleotides 2-8) and off-target mRNAs, and miRNAs downregulate target mRNA expression depending on the stability of the duplex formed between the 5' terminus of the miRNA and its target mRNA. I further discuss the possibility that such thermodynamic features of silencing efficiency may have arisen during evolution with increasing body temperature in various organisms. PMID:27187367

  4. Transcriptional regulation of human small nuclear RNA genes

    PubMed Central

    Jawdekar, Gauri W.; Henry, R. William

    2009-01-01

    The products of human snRNA genes have been frequently described as performing housekeeping functions and their synthesis refractory to regulation. However, recent studies have emphasized that snRNA and other related non-coding RNA molecules control multiple facets of the central dogma, and their regulated expression is critical to cellular homeostasis during normal growth and in response to stress. Human snRNA genes contain compact and yet powerful promoters that are recognized by increasingly well-characterized transcription factors, thus providing a premier model system to study gene regulation. This review summarizes many recent advances deciphering the mechanism by which the transcription of human snRNA and related genes are regulated. PMID:18442490

  5. Alternate rRNA secondary structures as regulators of translation.

    PubMed

    Feng, Shu; Li, Heng; Zhao, Jing; Pervushin, Konstantin; Lowenhaupt, Ky; Schwartz, Thomas U; Dröge, Peter

    2011-02-01

    Structural dynamics of large molecular assemblies are intricately linked to function. For ribosomes, macromolecular changes occur especially during mRNA translation and involve participation of ribosomal RNA. Without suitable probes specific to RNA secondary structure, however, elucidation of more subtle dynamic ribosome structure-function relationships, especially in vivo, remains challenging. Here we report that the Z-DNA- and Z-RNA-binding domain Zα, derived from the human RNA editing enzyme ADAR1-L, binds with high stability to specific rRNA segments of Escherichia coli and human ribosomes. Zα impaired in Z-RNA recognition does not associate with ribosomes. Notably, Zα(ADAR1)-ribosome interaction blocks translation in vitro and in vivo, with substantial physiological consequences. Our study shows that ribosomes can be targeted by a protein that specifically recognizes an alternate rRNA secondary structure, and suggests a new mechanism of translational regulation on the ribosome. PMID:21217697

  6. N(6)-methyladenosine-dependent RNA structural switches regulate RNA-protein interactions.

    PubMed

    Liu, Nian; Dai, Qing; Zheng, Guanqun; He, Chuan; Parisien, Marc; Pan, Tao

    2015-02-26

    RNA-binding proteins control many aspects of cellular biology through binding single-stranded RNA binding motifs (RBMs). However, RBMs can be buried within their local RNA structures, thus inhibiting RNA-protein interactions. N(6)-methyladenosine (m(6)A), the most abundant and dynamic internal modification in eukaryotic messenger RNA, can be selectively recognized by the YTHDF2 protein to affect the stability of cytoplasmic mRNAs, but how m(6)A achieves its wide-ranging physiological role needs further exploration. Here we show in human cells that m(6)A controls the RNA-structure-dependent accessibility of RBMs to affect RNA-protein interactions for biological regulation; we term this mechanism 'the m(6)A-switch'. We found that m(6)A alters the local structure in mRNA and long non-coding RNA (lncRNA) to facilitate binding of heterogeneous nuclear ribonucleoprotein C (HNRNPC), an abundant nuclear RNA-binding protein responsible for pre-mRNA processing. Combining photoactivatable-ribonucleoside-enhanced crosslinking and immunoprecipitation (PAR-CLIP) and anti-m(6)A immunoprecipitation (MeRIP) approaches enabled us to identify 39,060 m(6)A-switches among HNRNPC-binding sites; and global m(6)A reduction decreased HNRNPC binding at 2,798 high-confidence m(6)A-switches. We determined that these m(6)A-switch-regulated HNRNPC-binding activities affect the abundance as well as alternative splicing of target mRNAs, demonstrating the regulatory role of m(6)A-switches on gene expression and RNA maturation. Our results illustrate how RNA-binding proteins gain regulated access to their RBMs through m(6)A-dependent RNA structural remodelling, and provide a new direction for investigating RNA-modification-coded cellular biology. PMID:25719671

  7. Consequences of antisense down-regulation of a lignification-specific peroxidase on leaf and vascular tissue in tobacco lines demonstrating enhanced enzymic saccharification.

    PubMed

    Kavousi, Bahram; Daudi, Arsalan; Cook, Charis M; Joseleau, Jean-Paul; Ruel, Katia; Devoto, Alessandra; Bolwell, G Paul; Blee, Kristopher A

    2010-04-01

    Tobacco plants expressing an antisense construct for a cationic peroxidase, which down-regulated lignin content at the presumed level of polymerisation, have been further analysed. T(1) plants were derived from a large-scale screen of T(0) mutant lines, previously published, which identified lines demonstrating consistent lignin down-regulation. Of these, line 1074 which had the most robust changes in lignin distribution through several generations was shown to have accompanying down-regulation of transcription of most lignin biosynthesis genes, except cinnamoyl-CoA reductase. The consistent 20% reduction in lignin was not accompanied by significant gross changes in vascular polysaccharide content and composition, despite a modest up-regulation of transcripts of genes involved in cellulose and hemicellulose synthesis. Morphologically, 1074 plants have under-developed xylem with both fibers and vessels having thin cell walls and limited secondary wall thickening with an abnormal S2 layer. However, they were not compromised in overall growth. Nevertheless, these and other lines showed improved potential industrial utility through a threefold increase in enzymic saccharification efficiency compared with wild-type (wt). Therefore, they were profiled for further un-intended effects of transgenesis that might compromise their value for industrial or biofuel processes. Other phenotypic changes included increased leaf thickness and bifurcation at the tip of the leaf. wt-Plants had smaller chloroplasts and higher stomatal numbers than mutants. Transgenic lines also showed a variable leaf pigment distribution with light-green areas that contained measurably less chlorophyll a, b, and carotenoids. Changes in epidermal pavement cells of mutant lines were also observed after exposure to various chemicals, while wt leaves retained their structural integrity. Despite these changes, the mutant plants grew and were viable indicating that lignification patterns can be manipulated

  8. The requirement of c-Jun N-terminal kinase 2 in regulation of hypoxia-inducing factor-1α mRNA stability.

    PubMed

    Zhang, Dongyun; Li, Jingxia; Zhang, Min; Gao, Guangxun; Zuo, Zhenghong; Yu, Yonghui; Zhu, Linda; Gao, Jimin; Huang, Chuanshu

    2012-10-01

    The mRNA of hif-1α is considered as being constitutively and ubiquitously expressed, regardless of the level of oxygen tension. However many recent reports have showed that hif-1α mRNA could be regulated by natural antisense transcripts, potential microRNAs, and low O(2). In this study, it was found that a deficiency of JNK2 expression reduced HIF-1α protein induction in response to nickel treatment resulting from the impaired expression of hif-1α mRNA. Both the promoter luciferase assay and mRNA degradation assay clearly showed that depletion of JNK2 affected stability of hif-1α mRNA, rather than regulated its transcription. In addition, nucleolin, a classic histone chaperone, was demonstrated to physically bind to hif-1α mRNA and maintain its stability. Further investigation indicated that JNK2 regulated nucleolin expression and might in turn stabilize hif-1α mRNA. Collectively, we provided one more piece of evidence for the oncogenic role of JNK2 and nucleolin in regulating the cancer microenvironments by controlling HIF-1α expression. PMID:22910906

  9. Long non-coding RNA ANRIL is up-regulated in bladder cancer and regulates bladder cancer cell proliferation and apoptosis through the intrinsic pathway.

    PubMed

    Zhu, Hongxue; Li, Xuechao; Song, Yarong; Zhang, Peng; Xiao, Yajun; Xing, Yifei

    2015-11-13

    Antisense non-coding RNA in the INK4 locus (ANRIL) is a member of long non-coding RNAs and has been reported to be dysregulated in several human cancers. However, the role of ANRIL in bladder cancer remains unclear. This present study aimed to investigate whether and how ANRIL involved in bladder cancer. Our results showed up-regulation of ANRIL in bladder cancer tissues versus the corresponding adjacent non-tumor tissues. To explore the specific mechanisms, ANRIL was silenced by small interfering RNA or short hairpin RNA transfection in human bladder cancer T24 and EJ cells. Knockdown of ANRIL repressed cell proliferation and increased cell apoptosis, along with decreased expression of Bcl-2 and increased expressions of Bax, cytoplasmic cytochrome c and Smac and cleaved caspase-9, caspase-3 and PARP. However, no change of cleaved caspase-8 level was observed. Furthermore, in vivo experiment confirmed that knockdown of ANRIL inhibited tumorigenic ability of EJ cells in nude mice. Meanwhile, in accordance with in vitro study, knockdown of ANRIL inhibited expression of Bcl-2 and up-regulated expressions of Bax and cleaved caspase-9, but did not affect cleaved caspase-8 level. In conclusion, we first report that ANRIL possibly serves as an oncogene in bladder cancer and regulates bladder cancer cell proliferation and apoptosis through the intrinsic apoptosis pathway. PMID:26449463

  10. Fast Prediction of RNA-RNA Interaction

    NASA Astrophysics Data System (ADS)

    Salari, Raheleh; Backofen, Rolf; Sahinalp, S. Cenk

    Regulatory antisense RNAs are a class of ncRNAs that regulate gene expression by prohibiting the translation of an mRNA by establishing stable interactions with a target sequence. There is great demand for efficient computational methods to predict the specific interaction between an ncRNA and its target mRNA(s). There are a number of algorithms in the literature which can predict a variety of such interactions - unfortunately at a very high computational cost. Although some existing target prediction approaches are much faster, they are specialized for interactions with a single binding site.

  11. Functions and Regulation of RNA Editing by ADAR Deaminases

    PubMed Central

    Nishikura, Kazuko

    2010-01-01

    One type of RNA editing converts adenosines to inosines (A→I editing) in double-stranded RNA (dsRNA) substrates. A→I RNA editing is mediated by adenosine deaminase acting on RNA (ADAR) enzymes. A→I RNA editing of protein-coding sequences of a limited number of mammalian genes results in recoding and subsequent alterations of their functions. However, A→I RNA editing most frequently targets repetitive RNA sequences located within introns and 5′ and 3′ untranslated regions (UTRs). Although the biological significance of noncoding RNA editing remains largely unknown, several possibilities, including its role in the control of endogenous short interfering RNAs (esiRNAs), have been proposed. Furthermore, recent studies have revealed that the biogenesis and functions of certain microRNAs (miRNAs) are regulated by the editing of their precursors. Here, I review the recent findings that indicate new functions for A→I editing in the regulation of noncoding RNAs and for interactions between RNA editing and RNA interference mechanisms. PMID:20192758

  12. Small RNA-mediated chromatin silencing directed to the 3' region of the Arabidopsis gene encoding the developmental regulator, FLC.

    PubMed

    Swiezewski, Szymon; Crevillen, Pedro; Liu, Fuquan; Ecker, Joseph R; Jerzmanowski, Andrzej; Dean, Caroline

    2007-02-27

    Small RNA-mediated chromatin silencing is well characterized for repeated sequences and transposons, but its role in regulating single-copy endogenous genes is unclear. We have identified two small RNAs (30 and 24 nucleotides) corresponding to the reverse strand 3' to the canonical poly(A) site of FLOWERING LOCUS C (FLC), an Arabidopsis gene encoding a repressor of flowering. Genome searches suggest that these RNAs originate from the FLC locus in a genomic region lacking repeats. The 24-nt small RNA, which is most abundant in developing fruits, is absent in mutants defective in RNA polymerase IVa, RNA-DEPENDENT RNA POLYMERASE 2, and DICER-LIKE 3, components required for RNAi-mediated chromatin silencing. The corresponding genomic region shows histone 3 lysine 9 dimethylation, which was reduced in a dcl2,3,4 triple mutant. Investigations into the origins of the small RNAs revealed a polymerase IVa-dependent spliced, antisense transcript covering the 3' FLC region. Mutation of this genomic region by T-DNA insertion led to FLC misexpression and delayed flowering, suggesting that RNAi-mediated chromatin modification is an important component of endogenous pathways that function to suppress FLC expression. PMID:17360694

  13. MicroRNA regulation of lymphocyte tolerance and autoimmunity

    PubMed Central

    Simpson, Laura J.; Ansel, K. Mark

    2015-01-01

    Understanding the cell-intrinsic cues that permit self-reactivity in lymphocytes, and therefore autoimmunity, requires an understanding of the transcriptional and posttranscriptional regulation of gene expression in these cells. In this Review, we address seminal and recent research on microRNA (miRNA) regulation of central and peripheral tolerance. Human and mouse studies demonstrate that the PI3K pathway is a critical point of miRNA regulation of immune cell development and function that affects the development of autoimmunity. We also discuss how miRNA expression profiling in human autoimmune diseases has inspired mechanistic studies of miRNA function in the pathogenesis of multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus, type 1 diabetes, and asthma. PMID:26030228

  14. Sense-, antisense- and RNAi-4CL1 regulate soluble phenolic acids, cell wall components and growth in transgenic Populus tomentosa Carr.

    PubMed

    Tian, Xiaoming; Xie, Jin; Zhao, Yanling; Lu, Hai; Liu, Shichang; Qu, Long; Li, Jianmei; Gai, Ying; Jiang, Xiangning

    2013-04-01

    Regulation of lignin biosynthesis affects plant growth and wood properties. Transgenic downregulation of 4-coumarate:coenzyme A ligase (4CL, EC 6.2.1.12) may reduce lignin content in cell walls, which could improve the qualities of pulp in papermaking and increase the efficiency of bioenergy applications. To determine the effects of Ptc4CL1 on lignin biosynthesis and plant growth, Populus tomentosa Carr. was transformed using sense-, antisense-, and RNAi-4CL1 genes. The growth properties, gene expression, enzyme activity, lignin content and composition and content of soluble phenolic acids were investigated in 1-year-old field-grown transgenic poplar trees. Transgenic up- and down-regulation of 4CL1 altered lignin content and composition in transgenic poplars, but there were no negative effects on the growth of transgenic plants. In addition, the severe changes in auxin observed in transgenic lines led to significantly enhanced growth performance. Furthermore, lignin content was tightly correlated with the alteration of 4CL1 enzymatic activity, which was correlated with 4CL1 gene expression. A significant increase in S units in lignin with a slight increase in sinapic acid was observed in 4CL1 down-regulated transgenic poplars. These results suggest that 4CL1 is a traffic control gene in monolignol biosynthesis and confirm that 4CL1 activity has been implicated with sinapoyl activation. Finally, our data demonstrate that there is cross-correlation among 4CL1 gene expression, 4CL1 enzyme activity, soluble phenolic acid, lignin monomer biosynthesis, and lignin content. PMID:23434928

  15. Theoretical studies on sRNA-mediated regulation in bacteria

    NASA Astrophysics Data System (ADS)

    Chang, Xiao-Xue; Xu, Liu-Fang; Shi, Hua-Lin

    2015-12-01

    Small RNA(sRNA)-mediated post-transcriptional regulation differs from protein-mediated regulation. Through base-pairing, sRNA can regulate the target mRNA in a catalytic or stoichiometric manner. Some theoretical models were built for comparison of the protein-mediated and sRNA-mediated modes in the steady-state behaviors and noise properties. Many experiments demonstrated that a single sRNA can regulate several mRNAs, which causes crosstalk between the targets. Here, we focus on some models in which two target mRNAs are silenced by the same sRNA to discuss their crosstalk features. Additionally, the sequence-function relationship of sRNA and its role in the kinetic process of base-pairing have been highlighted in model building. Project supported by the National Basic Research Program of China (Grant No. 2013CB834100), the National Natural Science Foundation of China (Grant Nos. 11121403 and 11274320), the Open Project Program of State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, China (Grant No. Y4KF171CJ1), the National Natural Science Foundation for Young Scholar of China (Grant No. 11304115), and the China Postdoctoral Science Foundation (Grant No. 2013M541282).

  16. Transferrin Receptor-Targeted Lipid Nanoparticles for Delivery of an Antisense Oligodeoxyribonucleotide against Bcl-2

    PubMed Central

    Yang, Xiaojuan; Koh, Chee Guan; Liu, Shujun; Pan, Xiaogang; Santhanam, Ramasamy; Yu, Bo; Peng, Yong; Pang, Jiuxia; Golan, Sharon; Talmon, Yeshayahu; Jin, Yan; Muthusamy, Natarajan; Byrd, John C.; Chan, Kenneth K.; Lee, L. James; Marcucci, Guido; Lee, Robert J.

    2013-01-01

    Antisense oligonucleotide G3139-mediated down-regulation of Bcl-2 is a potential strategy for overcoming chemoresistance in leukemia. However, the limited efficacy shown in recent clinical trials calls attention to the need for further development of novel and more efficient delivery systems. In order to address this issue, transferrin receptor (TfR)-targeted, protamine-containing lipid nanoparticles (Tf-LNs) were synthesized as delivery vehicles for G3139. The LNs were produced by an ethanol dilution method and lipid-conjugated Tf ligand was then incorporated by a post-insertion method. The resulting Tf-LNs had a mean particle diameter of ~ 90 nm and G3139 loading efficiency of 90.4%. Antisense delivery efficiency of Tf-LNs was evaluated in K562, MV4-11 and Raji leukemia cell lines. The results showed that Tf-LNs were more effective than non-targeted LNs and free G3139 (p <0.05) in decreasing Bcl-2 expression (by up to 62% at the mRNA level in K562 cells) and in inducing caspase-dependent apoptosis. In addition, Bcl-2 down-regulation and apoptosis induced by Tf-LN G3139 were shown to be blocked by excess free Tf and thus were TfR-dependent. Cell lines with higher TfR expression also showed greater Bcl-2 down-regulation. Furthermore, upregulation of TfR expression in leukemia cells by iron chelator deferoxamine resulted in a further increase in antisense effect (up to 79% Bcl-2 reduction in K562 at the mRNA level) and in caspase-dependent apoptosis (by ~ 3-fold) by Tf-LN. Tf-LN mediated delivery combined with TfR up-regulation by deferoxamine appears to be a potentially promising strategy for enhancing the delivery efficiency and therapeutic efficacy of antisense oligonucleotides. PMID:19183107

  17. RNA exosome regulated long non-coding RNA transcription controls super-enhancer activity

    PubMed Central

    Pefanis, Evangelos; Wang, Jiguang; Rothschild, Gerson; Lim, Junghyun; Kazadi, David; Sun, Jianbo; Federation, Alexander; Chao, Jaime; Elliott, Oliver; Liu, Zhi-Ping; Economides, Aris N.; Bradner, James E.; Rabadan, Raul; Basu, Uttiya

    2015-01-01

    We have ablated the cellular RNA degradation machinery in differentiated B cells and pluripotent embryonic stem (ES) cells by conditional mutagenesis of core (Exosc3) and nuclear RNase (Exosc10) components of RNA exosome and identified a vast number of long non-coding RNAs (lncRNAs) and enhancer RNAs (eRNAs) with emergent functionality. Unexpectedly, eRNA-expressing regions accumulate R-loop structures upon RNA exosome ablation, thus demonstrating the role of RNA exosome in resolving deleterious DNA/RNA hybrids arising from active enhancers. We have uncovered a distal divergent eRNA-expressing element (lncRNA-CSR) engaged in long-range DNA interactions and regulating IgH 3’ regulatory region super-enhancer function. CRISPRCas9 mediated ablation of lncRNA-CSR transcription decreases its chromosomal looping-mediated association with the IgH 3’regulatory region super-enhancer and leads to decreased class switch recombination efficiency. We propose that the RNA exosome protects divergently transcribed lncRNA expressing enhancers, by resolving deleterious transcription-coupled secondary DNA structures, while also regulating long-range super-enhancer chromosomal interactions important for cellular function. PMID:25957685

  18. RNA exosome-regulated long non-coding RNA transcription controls super-enhancer activity.

    PubMed

    Pefanis, Evangelos; Wang, Jiguang; Rothschild, Gerson; Lim, Junghyun; Kazadi, David; Sun, Jianbo; Federation, Alexander; Chao, Jaime; Elliott, Oliver; Liu, Zhi-Ping; Economides, Aris N; Bradner, James E; Rabadan, Raul; Basu, Uttiya

    2015-05-01

    We have ablated the cellular RNA degradation machinery in differentiated B cells and pluripotent embryonic stem cells (ESCs) by conditional mutagenesis of core (Exosc3) and nuclear RNase (Exosc10) components of RNA exosome and identified a vast number of long non-coding RNAs (lncRNAs) and enhancer RNAs (eRNAs) with emergent functionality. Unexpectedly, eRNA-expressing regions accumulate R-loop structures upon RNA exosome ablation, thus demonstrating the role of RNA exosome in resolving deleterious DNA/RNA hybrids arising from active enhancers. We have uncovered a distal divergent eRNA-expressing element (lncRNA-CSR) engaged in long-range DNA interactions and regulating IgH 3' regulatory region super-enhancer function. CRISPR-Cas9-mediated ablation of lncRNA-CSR transcription decreases its chromosomal looping-mediated association with the IgH 3' regulatory region super-enhancer and leads to decreased class switch recombination efficiency. We propose that the RNA exosome protects divergently transcribed lncRNA expressing enhancers by resolving deleterious transcription-coupled secondary DNA structures, while also regulating long-range super-enhancer chromosomal interactions important for cellular function. PMID:25957685

  19. Epigenetic and microRNA regulation during osteoarthritis development

    PubMed Central

    Chen, Di; Shen, Jie; Hui, Tianqian

    2015-01-01

    Osteoarthritis (OA) is a common degenerative joint disease, the pathological mechanism of which is currently unknown. Genetic alteration is one of the key contributing factors for OA pathology. Recent evidence suggests that epigenetic and microRNA regulation of critical genes may contribute to OA development. In this article, we review the epigenetic and microRNA regulations of genes related to OA development. Potential therapeutic strategies may be developed on the basis of novel findings.

  20. Antisense Down-Regulation of the FaPG1 Gene Reveals an Unexpected Central Role for Polygalacturonase in Strawberry Fruit Softening1[W

    PubMed Central

    Quesada, Miguel A.; Blanco-Portales, Rosario; Posé, Sara; García-Gago, Juan A.; Jiménez-Bermúdez, Silvia; Muñoz-Serrano, Andrés; Caballero, José L.; Pliego-Alfaro, Fernando; Mercado, José A.; Muñoz-Blanco, Juan

    2009-01-01

    The strawberry (Fragaria × ananassa ‘Chandler’) fruit undergoes a fast softening during ripening. Polygalacturonase (PG) activity is low during this process, but two ripening-related PG genes, FaPG1 and FaPG2, have been cloned. Both genes were up-regulated during fruit ripening and were also negatively regulated by auxin. To further assess the role of FaPG1 on strawberry softening, transgenic plants containing an antisense sequence of this gene under the control of the 35S promoter (APG lines) were obtained. Sixteen out of 30 independent transgenic lines showed fruit yields similar to those of the control. Several quality parameters were measured in ripe fruits from these 16 lines. Fruit weight was slightly reduced in four lines, and most of them showed an increase in soluble solid content. Half of these lines yielded fruits significantly firmer than did the control. Four APG lines were selected, their ripened fruits being on average 163% firmer than the control. The postharvest softening of APG fruits was also diminished. Ripened fruits from the four selected lines showed a 90% to 95% decrease in FaPG1 transcript abundance, whereas the level of FaPG2 was not significantly altered. Total PG activity was reduced in three of these lines when compared with control fruits. Cell wall extracts from APG fruits showed a reduction in pectin solubilization and an increase in pectins covalently bound to the cell wall. A comparative transcriptomic analysis of gene expression between the ripened receptacle of the control and those of the APG fruits (comprising 1,250 receptacle expressed sequence tags) did not show any statistically significant change. These results indicate that FaPG1 plays a central role in strawberry softening. PMID:19395408

  1. RNA-RNA interactions in gene regulation: the coding and noncoding players.

    PubMed

    Guil, Sonia; Esteller, Manel

    2015-05-01

    The past few years have witnessed an exciting increase in the richness and complexity of RNA-mediated regulatory circuitries, including new types of RNA-RNA interaction that underlie key steps in gene expression control in an organized and probably hierarchic system to dictate final protein output. Both small (especially miRNAs) and long coding (lc) and noncoding (nc) RNAs contain structural domains that can sense and bind other RNAs via complementary base pairing. The versatility of the interaction confers multiple roles to RNA-RNA hybrids, from control of RNA biogenesis to competition for common targets. Here, we focus on the emerging evidence around RNA networks and their impact on gene expression regulation in light of recent breakthroughs around the crosstalk between coding RNAs and ncRNAs. PMID:25818326

  2. MicroRNA-27b Regulates Mitochondria Biogenesis in Myocytes

    PubMed Central

    Zhang, Shunhua; Du, Jingjing; Bai, Lin; Zhang, Yi; Jiang, Yanzhi; Li, Xuewei; Wang, Jinyong; Zhu, Li

    2016-01-01

    MicroRNAs (miRNAs) are small, non-coding RNAs that affect the post-transcriptional regulation of various biological pathways. To date, it is not fully understood how miRNAs regulate mitochondrial biogenesis. This study aimed at the identification of the role of miRNA-27b in mitochondria biogenesis. The mitochondria content in C2C12 cells was significantly increased during myogenic differentiation and accompanied by a marked decrease of miRNA-27b expression. Furthermore, the expression of the predicted target gene of miRNA-27b, forkhead box j3 (Foxj3), was also increased during myogenic differentiation. Luciferase activity assays confirmed that miRNA-27b directly targets the 3’-untranslated region (3’-UTR) of Foxj3. Overexpression of miRNA-27b provoked a decrease of mitochondria content and diminished expression of related mitochondrial genes and Foxj3 both at mRNA and protein levels. The expression levels of downstream genes of Foxj3, such as Mef2c, PGC1α, NRF1 and mtTFA, were also decreased in C2C12 cells upon overexpression of miRNA-27b. These results suggested that miRNA-27b may affect mitochondria biogenesis by down-regulation of Foxj3 during myocyte differentiation. PMID:26849429

  3. tRNA modifications regulate translation during cellular stress

    PubMed Central

    Gu, Chen; Begley, Thomas J.; Dedon, Peter C.

    2014-01-01

    The regulation of gene expression in response to stress is an essential cellular protection mechanism. Recent advances in tRNA modification analysis and genome-based codon bias analytics have facilitated studies that lead to a novel model for translational control, with translation elongation dynamically regulated during stress responses. Stress-induced increases in specific anticodon wobble bases are required for the optimal translation of stress response transcripts that are significantly biased in the use of degenerate codons keyed to these modified tRNA bases. These findings led us to introduce the notion of tRNA modification tunable transcripts (MoTTs – transcripts whose translation is regulated by tRNA modifications), which are identifiable using genome-wide codon counting algorithms. In support of this general model of translational control of stress response, studies making use of detailed measures of translation, tRNA methyltransferase mutants, and computational and mass spectrometry approaches reveal that stress reprograms tRNA modifications to translationally regulate MoTTs linked to arginine and leucine codons, which helps cells survive insults by damaging agents. These studies highlight how tRNA methyltransferase activities and MoTTs are key components of the cellular stress response. PMID:25304425

  4. Patterns and regulation of ribosomal RNA transcription in Borrelia burgdorferi

    PubMed Central

    2011-01-01

    Background Borrelia burgdorferi contains one 16S and two tandem sets of 23S-5S ribosomal (r) RNA genes whose patterns of transcription and regulation are unknown but are likely to be critical for survival and persistence in its hosts. Results RT-PCR of B. burgdorferi N40 and B31 revealed three rRNA region transcripts: 16S rRNA-alanine transfer RNA (tRNAAla); tRNAIle; and both sets of 23S-5S rRNA. At 34°C, there were no differences in growth rate or in accumulation of total protein, DNA and RNA in B31 cultured in Barbour-Stoenner-Kelly (BSK)-H whether rabbit serum was present or not. At 23°C, B31 grew more slowly in serum-containing BSK-H than at 34°C. DNA per cell was higher in cells in exponential as compared to stationary phase at either temperature; protein per cell was similar at both temperatures in both phases. Similar amounts of rRNA were produced in exponential phase at both temperatures, and rRNA was down-regulated in stationary phase at either temperature. Interestingly, a relBbu deletion mutant unable to generate (p)ppGpp did not down-regulate rRNA at transition to stationary phase in serum-containing BSK-H at 34°C, similar to the relaxed phenotype of E. coli relA mutants. Conclusions We conclude that rRNA transcription in B. burgdorferi is complex and regulated both by growth phase and by the stringent response but not by temperature-modulated growth rate. PMID:21251259

  5. A long non-coding RNA, APOA4-AS, regulates APOA4 expression depending on HuR in mice.

    PubMed

    Qin, Wangshu; Li, Xinzhi; Xie, Liwei; Li, Sha; Liu, Jianan; Jia, Linna; Dong, Xue; Ren, Xiaomeng; Xiao, Junjie; Yang, Changqing; Zhou, Yifa; Chen, Zheng

    2016-07-27

    Long non-coding RNAs (lncRNAs) have been shown to be critical biomarkers or therapeutic targets for human diseases. However, only a small number of lncRNAs were screened and characterized. Here, we identified 15 lncRNAs, which are associated with fatty liver disease. Among them, APOA4-AS is shown to be a concordant regulator of Apolipoprotein A-IV (APOA4) expression. APOA4-AS has a similar expression pattern with APOA4 gene. The expressions of APOA4-AS and APOA4 are both abnormally elevated in the liver of ob/ob mice and patients with fatty liver disease. Knockdown of APOA4-AS reduces APOA4 expression both in vitro and in vivo and leads to decreased levels of plasma triglyceride and total cholesterol in ob/ob mice. Mechanistically, APOA4-AS directly interacts with mRNA stabilizing protein HuR and stabilizes APOA4 mRNA. Deletion of HuR dramatically reduces both APOA4-AS and APOA4 transcripts. This study uncovers an anti-sense lncRNA (APOA4-AS), which is co-expressed with APOA4, and concordantly and specifically regulates APOA4 expression both in vitro and in vivo with the involvement of HuR. PMID:27131369

  6. Selection of antisense oligodeoxynucleotides against glutathione S-transferase Mu.

    PubMed Central

    't Hoen, Peter A C; Out, Ruud; Commandeur, Jan N M; Vermeulen, Nico P E; van Batenburg, F H D; Manoharan, Muthiah; van Berkel, Theo J C; Biessen, Erik A L; Bijsterbosch, Martin K

    2002-01-01

    The aim of the present study was to identify functional antisense oligodeoxynucleotides (ODNs) against the rat glutathione S-transferase Mu (GSTM) isoforms, GSTM1 and GSTM2. These antisense ODNs would enable the study of the physiological consequences of GSTM deficiency. Because it has been suggested that the effectiveness of antisense ODNs is dependent on the secondary mRNA structures of their target sites, we made mRNA secondary structure predictions with two software packages, Mfold and STAR. The two programs produced only marginally similar structures, which can probably be attributed to differences in the algorithms used. The effectiveness of a set of 18 antisense ODNs was evaluated with a cell-free transcription/translation assay, and their activity was correlated with the predicted secondary RNA structures. Four phosphodiester ODNs specific for GSTM1, two ODNs specific for GSTM2, and four ODNs targeted at both GSTM isoforms were found to be potent, sequence-specific, and RNase H-dependent inhibitors of protein expression. The IC50 value of the most potent ODN was approximately 100 nM. Antisense ODNs targeted against regions that were predicted by STAR to be predominantly single stranded were more potent than antisense ODNs against double-stranded regions. Such a correlation was not found for the Mfold prediction. Our data suggest that simulation of the local folding of RNA facilitates the discovery of potent antisense sequences. In conclusion, we selected several promising antisense sequences, which, when synthesized as biologically stable oligonucleotides, can be applied for study of the physiological impact of reduced GSTM expression. PMID:12515389

  7. Single cell analysis of RNA-mediated histone H3.3 recruitment to a cytomegalovirus promoter-regulated transcription site.

    PubMed

    Newhart, Alyshia; Rafalska-Metcalf, Ilona U; Yang, Tian; Joo, Lucy M; Powers, Sara Lawrence; Kossenkov, Andrew V; Lopez-Jones, Melissa; Singer, Robert H; Showe, Louise C; Skordalakes, Emmanuel; Janicki, Susan M

    2013-07-01

    Unlike the core histones, which are incorporated into nucleosomes concomitant with DNA replication, histone H3.3 is synthesized throughout the cell cycle and utilized for replication-independent (RI) chromatin assembly. The RI incorporation of H3.3 into nucleosomes is highly conserved and occurs at both euchromatin and heterochromatin. However, neither the mechanism of H3.3 recruitment nor its essential function is well understood. Several different chaperones regulate H3.3 assembly at distinct sites. The H3.3 chaperone, Daxx, and the chromatin-remodeling factor, ATRX, are required for H3.3 incorporation and heterochromatic silencing at telomeres, pericentromeres, and the cytomegalovirus (CMV) promoter. By evaluating H3.3 dynamics at a CMV promoter-regulated transcription site in a genetic background in which RI chromatin assembly is blocked, we have been able to decipher the regulatory events upstream of RI nucleosomal deposition. We find that at the activated transcription site, H3.3 accumulates with sense and antisense RNA, suggesting that it is recruited through an RNA-mediated mechanism. Sense and antisense transcription also increases after H3.3 knockdown, suggesting that the RNA signal is amplified when chromatin assembly is blocked and attenuated by nucleosomal deposition. Additionally, we find that H3.3 is still recruited after Daxx knockdown, supporting a chaperone-independent recruitment mechanism. Sequences in the H3.3 N-terminal tail and αN helix mediate both its recruitment to RNA at the activated transcription site and its interaction with double-stranded RNA in vitro. Interestingly, the H3.3 gain-of-function pediatric glioblastoma mutations, G34R and K27M, differentially affect H3.3 affinity in these assays, suggesting that disruption of an RNA-mediated regulatory event could drive malignant transformation. PMID:23689370

  8. TRIM-NHL proteins take on miRNA regulation.

    PubMed

    Loedige, Inga; Filipowicz, Witold

    2009-03-01

    The TRIM-NHL family of proteins is conserved among metazoans and has been shown to regulate cell proliferation and development. In this issue, Hammell et al. (2009) and Schwamborn et al. (2009) identify two members of this protein family, NHL-2 in worms and TRIM32 in mice, as positive regulators of microRNA function. PMID:19269362

  9. Differential regulation of plastid mRNA stability. Progress report

    SciTech Connect

    Stern, D.B.

    1993-09-01

    Our goal is to identify cis-acting sequences and transacting factors that function in plastid mRNA maturation, stabilization, and/or decay through an in vitro and in vivo analysis of mRNA:protein interactions. Our previous results emphasized the study of 3{prime}end inverted repeat sequences (IRs) that serve both as mRNA processing elements and stability determinants, and associate with plastid proteins that potentially play enzymatic, structural and/or regulatory roles. We seek to define, by single base and internal deletion mutagenesis, the sequence and structural requirements for protein binding to the 3{prime} IRs of petD and psbA mRNAs; to purify RNA-binding proteins that demonstrate gene- or sequence-specific binding, or that are implicated in RNA stabilization or decay; and to investigate the native form of mRNA in the plastid, by attempting to purify ribonucleoprotein (RNP) particles from organelles. Our view of mRNA decay is that it is regulated by three interactive components: RNA structure, ribonucleases and RNA-binding proteins. We have used mutagenesis to study the role of RNA structure in regulating RNA decay rates, and to identify protein binding and endonuclease recognition sites. We have identified at least three endonuclease activities; one that cleaves psbA RNA; and two whose cleavage patterns with petD 3{prime} IR-RNA has been studied (endoC1 and endoC2). Additionally, we have continued to analyze the properties of the major RNA processing exoribonuclease. We have concentrated our efforts on three RNA-binding proteins. A 100 kd protein with properties suggestive of a mammalian RNP component has been purified. A protein of 55 kd that may also be an endonuclease has been partially purified. We have studied the interaction of a 29 kd protein with the petD stem/loop, and its role in RNA processing. Recently, we have used a novel gel shift/SDS-PAGE technique to identify new RNA-binding proteins.

  10. mRNA modifications: Dynamic regulators of gene expression?

    PubMed Central

    Hoernes, Thomas Philipp; Hüttenhofer, Alexander; Erlacher, Matthias David

    2016-01-01

    ABSTRACT The expression of a gene is a tightly regulated process and is exerted by a myriad of different mechanisms. Recently, RNA modifications located in coding sequences of mRNAs, have been identified as potential regulators of gene expression. N6-methyladenosine (m6A), 5-methylcytosine (m5C), pseudouridine (Ψ) and N1-methyladenosine (m1A) have been found within open reading frames of mRNAs. The presence of these mRNA modifications has been implicated to modulate the fate of an mRNA, ranging from maturation to its translation and even degradation. However, many aspects concerning the biological functions of mRNA modifications remain elusive. Recently, systematic in vitro studies allowed a first glimpse of the direct interplay of mRNA modifications and the efficiency and fidelity of ribosomal translation. It thereby became evident that the effects of mRNA modifications were, astonishingly versatile, depending on the type, position or sequence context. The incorporation of a single modification could either prematurely terminate protein synthesis, reduce the peptide yield or alter the amino acid sequence identity. These results implicate that mRNA modifications are a powerful mechanism to post-transcriptionally regulate gene expression. PMID:27351916