Alternative conformations of the ColE1 replication primer modulate its interaction with RNA I

Wong, Edwin M.; Polisky, Barry

doi:10.1016/0092-8674(85)90292-2

Cited by 49 publications

(33 citation statements)

References 15 publications

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“…Importantly, in both cases, mutating the splice sites of the upstream introns abolishes their enhancing effect, indicating that their splicing per se is important. It has been proposed that the presence or absence of upstream introns can confer different secondary transcript structures, potentially influencing the efficiency of the splicing reaction (Tomizawa and Itoh 1981;Wong and Polisky 1985;Watakabe et al 1989;Clouet d'Orval et al 1991). In light of our results, we favor the hypothesis that deposition of the EJC at adjacent splice junctions could explain the positive influence of upstream introns.…”

Section: A Novel Function For the Pre-ejc And Splicing Factor Rnps1supporting

confidence: 60%

The exon junction complex controls transposable element activity by ensuring faithful splicing of the piwi transcript

et al. 2014

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The exon junction complex (EJC) is a highly conserved ribonucleoprotein complex that binds RNAs during splicing and remains associated with them following export to the cytoplasm. While the role of this complex in mRNA localization, translation, and degradation has been well characterized, its mechanism of action in splicing a subset of Drosophila and human transcripts remains to be elucidated. Here, we describe a novel function for the EJC and its splicing subunit, RnpS1, in preventing transposon accumulation in both Drosophila germline and surrounding somatic follicle cells. This function is mediated specifically through the control of piwi transcript splicing, where, in the absence of RnpS1, the fourth intron of piwi is retained. This intron contains a weak polypyrimidine tract that is sufficient to confer dependence on RnpS1. Finally, we demonstrate that RnpS1-dependent removal of this intron requires splicing of the flanking introns, suggesting a model in which the EJC facilitates the splicing of weak introns following its initial deposition at adjacent exon junctions. These data demonstrate a novel role for the EJC in regulating piwi intron excision and provide a mechanism for its function during splicing.

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Section: A Novel Function For the Pre-ejc And Splicing Factor Rnps1supporting

confidence: 60%

The exon junction complex controls transposable element activity by ensuring faithful splicing of the piwi transcript

et al. 2014

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“…Processing of RNA-II by RNase H to form a functional primer for initiation of ColEl replication in vitro is inhibited by the binding of RNA-I to its target in RNA-II (34,35). Recently, in vitro transcription experiments have shown that there is a structural rearrangement of ColEl preprimer RNA during the early stages of its synthesis (15,44). The binding of RNA-I to RNA-II may prevent the formation of a secondary structure required for initiation of replication (15), which may be similar to the mechanism proposed for the interaction of RNA-E with the repAl mRNA in the case of IncFII plasmid NR1 (28).…”

Section: Resultsmentioning

confidence: 99%

Transcriptional pausing in a region important for plasmid NR1 replication control

1987

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The results of in vitro single-round transcription experiments indicated that RNA polymerase pauses during transcription of the leader region that precedes the repAl gene of IncFII plasmid NR1. Transcription initiated at either of the two transcription promoter sites of the repAl gene, which encodes the essential replication initiation protein of NR1, was observed to pause in this region. Pausing was specifically enhanced by addition of NusA protein, an Escherichia coli transcription accessory factor. Northern blot RNA-DNA hybridization analysis of repAl mRNA synthesized in vivo revealed RNA species that had lengths equivalent to those of the in vitro-paused intermediates. The steady-state rate of in vivo repAl mRNA transcription downstream from the pause sites (measured by quantitative hybridization of pulse-labeled RNA to DNA probes complementary to different segments of repAl mRNA) was not appreciably affected, which suggests that the pause sites do not promote premature termination of transcription. The pause sites were located between the target sequence within the leader region of the mRNA that interacts with a 91-base countertranscript and the beginning of the repAl coding sequence. Because the countertranscript is an inhibitor of translation of repAl mRNA, transcriptional pausing in this region may be an important feature of the regulation of RepAl synthesis, which is the mechanism by which plasmid NR1 controls its replication.

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“…This effect could result either from the presence of a functional intron or from structural differences between the primary transcripts. For example, the presence or absence of upstream introns could confer different secondary structures to the transcripts (Tomizawa and Itoh 1981;Wong and Polisky 1985) and, thus, regulate splicing (Watakabe et al 1989;Clouet d'Orval et al 1991;Domenjoud et al 1991). Alternatively, it has been observed in other genes that specific sequence elements, distinct from the splice sites, can increase the efficiency of splicing of a nearby intron (Watakabe et al 1993, Xu et al 1993.…”

Section: Discussionmentioning

confidence: 99%

In vivo cooperation between introns during pre-mRNA processing.

Neel¹,

Weil²,

Giansante³

et al. 1993

Genes Dev.

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In higher eukaryotes the large number of introns present in most genes implies that the pre-mRNA processing machinery should be efficient and accurate. Although this could be achieved at the level of each intron, an attractive alternative would be that interactions between introns improve the performance of this machinery. In this study we tested this hypothesis by comparing the processing of transcripts of the tumor necrosis factor I~ gene, which differ only by their number of introns. We took advantage of the ordered splicing of the three introns present in this gene to design constructs that should generate, as primary transcripts, molecules that are normally produced by splicing. We established that the apparent splicing rate of intron 3 is increased 2.5-and 3.5-fold by the presence of one or two other introns on the primary transcript, respectively. Similarly, the apparent splicing rate of intron 2 is increased by the presence of intron 1. As these effects involve the splice sites of the upstream intron, these observations support the existence of cooperative interactions between introns during pre-mRNA processing.[Key Words: Pre-mRNA processing; splicing; cooperation between introns; tumor necrosis factor 6]

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Alternative conformations of the ColE1 replication primer modulate its interaction with RNA I

Cited by 49 publications

References 15 publications

The exon junction complex controls transposable element activity by ensuring faithful splicing of the piwi transcript

The exon junction complex controls transposable element activity by ensuring faithful splicing of the piwi transcript

Transcriptional pausing in a region important for plasmid NR1 replication control

In vivo cooperation between introns during pre-mRNA processing.

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