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Use of Modified U1snRNAs to Inhibit HIV-1 ReplicationSajic, Rade 31 August 2011 (has links)
The rapid evolutionary rate of HIV-1 has lead to the emergence of multi-drug resistant variants, emphasizing the need for novel inhibitory methods. One such method could be based upon inhibiting viral gene expression through disruption of HIV-1 RNA processing. A means of accomplishing this goal is through use of modified U1snRNA variants that target highly conserved regions of HIV-1 at its terminal exon and prevent 3’ end formation. The modification consists of a 10-nucleotide substitution at the 5’ end complementary to the conserved HIV-1 regions. When modified U1snRNA targeted to HIV-1 were cotransfected with replication deficient HIV-1 proviruses, western blot indicated a specific and significant reduction in the level of viral protein production (p24 and gp120), while U1 constructs that lacked complementary sequences had no effect on HIV-1 protein expression. To further investigate targeted U1snRNA inhibitory effects on HIV-1, efforts are currently underway to determine if this approach has the ability to suppress protein expression in a gene therapeutic model. To date, suppression of viral protein production has reached 50% when tested with a moderately inhibitory U1snRNA. If shown to be effective, such an inhibition would be increased with the use of combinatory modified U1snRNA constructs producing a synergistic effect.
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Use of Modified U1snRNAs to Inhibit HIV-1 ReplicationSajic, Rade 31 August 2011 (has links)
The rapid evolutionary rate of HIV-1 has lead to the emergence of multi-drug resistant variants, emphasizing the need for novel inhibitory methods. One such method could be based upon inhibiting viral gene expression through disruption of HIV-1 RNA processing. A means of accomplishing this goal is through use of modified U1snRNA variants that target highly conserved regions of HIV-1 at its terminal exon and prevent 3’ end formation. The modification consists of a 10-nucleotide substitution at the 5’ end complementary to the conserved HIV-1 regions. When modified U1snRNA targeted to HIV-1 were cotransfected with replication deficient HIV-1 proviruses, western blot indicated a specific and significant reduction in the level of viral protein production (p24 and gp120), while U1 constructs that lacked complementary sequences had no effect on HIV-1 protein expression. To further investigate targeted U1snRNA inhibitory effects on HIV-1, efforts are currently underway to determine if this approach has the ability to suppress protein expression in a gene therapeutic model. To date, suppression of viral protein production has reached 50% when tested with a moderately inhibitory U1snRNA. If shown to be effective, such an inhibition would be increased with the use of combinatory modified U1snRNA constructs producing a synergistic effect.
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The transcriptome of barley chloroplasts revealed by deep sequencingZhelyazkova, Petya 03 January 2013 (has links)
Die gegenwärtige Vorstellung von Genexpression in Plastiden leitet sich von der Analyse weniger, individueller Gene ab und ist deshalb noch relativ lückenhaft. In dieser Arbeit sollte daher differenzierende RNA Sequenzierung- eine neue Methode, die zwischen prozessierten und Primärtranskripten unterscheiden kann, verwendet werden, um ein vollständigeres Bild des Transkriptionsprozesses und der RNA Prozessierung von Hordeum vulgare L. (Gerste) Chloroplasten zu erhalten. Plastidengene in höheren Pflanzen können sowohl von einer plastidenkodierten, bakterienähnlichen RNA-Polymerase (PEP), als auch von einer kernkodierten, phagenähnlichen RNA-Polymerase (NEP), die beide unterschiedliche Promotoren erkennen, abgelesen werden. In dieser Arbeit wurde die Verteilung von Transkriptionsstartstellen innerhalb des Plastidengenoms von grünen (reife Chloroplasten; Transkriptionsaktivität von PEP und NEP) und weißen Plastiden (Transkriptionsaktivität von NEP) der Gerstenmutantenlinie albostrians analysiert. Dies führte zu neuen Erkenntnissen bezüglich polymerasenspezifischer Genexpression in Plastiden. Auf Grundlage neuerer Arbeiten wird angenommen, daß nicht kodierende RNAs (ncRNAs) in Chloroplasten vorkommen. Die bisher verwendeten Methoden waren jedoch nicht geeignet, ncRNAs als Primärtranskripte zu identifizieren, die zumindest in Prokaryoten die häufigste Klasse von ncRNAs darstellen. In dieser Arbeit konnte durch dRNA-seq gezeigt werden, daß auch in Plastiden zahlreiche ncRNAs als Primärtranskripte generiert werden. Die wichtigsten Schritte im Prozess der mRNA Reifung in Plastiden sind 5´und 3´ Endformation und intercistronische Prozessierung. Vor Kurzem wurde gezeigt, daß ein PPR (Pentatricopeptide repeat) Protein zur Bildung der Ende von einigen prozessierten Plastiden mRNAs beiträgt, indem es als Hindernis für Exonukleasen wirkt. Mit dieser Arbeit konnte gezeigt werden, daß dies ein genereller Mechanismus zur Bildung prozessierter mRNA-Enden in Chloroplasten ist. / The current view on plastid gene expression is mainly based on the analysis of a few individual genes, and thus it is lacking in comprehensiveness. Here, a novel differential RNA-seq approach, designed to discriminate between primary and processed transcripts, was used to obtain a deeper insight into the plastid transcription and RNA maturation of mature barley (Hordeum vulgare L.) chloroplasts. Transcription in plastids of higher plants is dependent on two different transcription machineries, a plastid-encoded bacterial-type RNA polymerase (PEP) and a nuclear-encoded phage-type RNA polymerase (NEP), which recognize distinct types of promoters. This study provided a thorough investigation into the distribution of transcription start sites within the plastid genome of green (mature chloroplasts; transcription by both PEP and NEP) and white (PEP-deficient plastids; transcription by NEP) plastids of the barley line albostrians. This analysis led to new insights on polymerase specific gene expression in plastids. Recent studies have suggested that non-coding RNAs (ncRNAs) are common in chloroplasts. However, they did not directly detect ncRNAs generated via transcription, the so far most abundant class of known regulatory ncRNAs in bacteria. Here, dRNA-seq analysis of the transcriptome of barley chloroplasts demonstrated the existence of numerous ncRNA generated via transcription of free-standing genes. Major events in plastid mRNA maturation include 5’ and 3’ processed end formation and intercistronic processing. Recently, a PPR (pentatricopeptide repeat) protein was shown to participate in the generation of several plastid mRNA processed ends by serving as a barrier to exonucleases. This study provided evidence for the global impact of this mechanism on processed termini formation in chloroplasts.
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