Escherichia coli str. K-12 substr. MG1655
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ABSTRACT:
PROVIDER: PRJNA286969 | ENA |
REPOSITORIES: ENA
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Project description:In many gram-negative and some gram-positive bacteria small regulatory RNAs (sRNAs) that bind the RNA chaperone Hfq have a pivotal role in modulating virulence, stress responses, metabolism, and biofilm formation. These sRNAs recognize transcripts through base-pairing, and sRNA-mRNA annealing consequently alters the translation and/or stability of transcripts leading to changes in gene expression. We have previously found that the highly conserved 3'-to-5' exoribonuclease polynucleotide phosphorylase (PNPase) has an indispensable role in paradoxically stabilizing Hfq-bound sRNAs and promoting their function in gene regulation in Escherichia coli. Here, we report that PNPase uniquely contributes to the degradation of specific mRNA cleavage products, the majority of which bind Hfq and are derived from targets of sRNAs. Specifically, we found that these mRNA-derived fragments accumulate in the absence of PNPase or its exoribonuclease activity and interact with PNPase. Additionally, we show that mutations in hfq or in the seed pairing region of a sRNA eliminated the requirement of PNPase for sRNA stability. Altogether, our results are consistent with a model that PNPase degrades mRNA-derived fragments that could otherwise deplete cells of Hfq-binding sRNAs through pairing mediated decay.
2019-07-08 | GSE125368 | GEO
Project description:Human Polynucleotide Phosphorylase (hPNPaseold-35) is an evolutionarily conserved 3’→5’ exoribonuclease implicated in the regulation of numerous physiological processes like maintenance of mitochondrial homeostasis, mtRNA import and aging-associated inflammation. From an RNase perspective, little is known about the RNA or miRNA species it targets for degradation or whose expression it regulates; except for c-myc and miR-221.
2013-07-30 | GSE46884 | GEO
Project description:Human Polynucleotide Phosphorylase (hPNPaseold-35) is an evolutionarily conserved 3’→5’ exoribonuclease implicated in the regulation of numerous physiological processes like maintenance of mitochondrial homeostasis, mtRNA import and aging-associated inflammation. From an RNase perspective, little is known about the RNA or miRNA species it targets for degradation or whose expression it regulates; except for c-myc and miR-221.
2014-06-01 | GSE53604 | GEO
Project description:Chloroplast polynucleotide phosphorylase null mutant (pnp1-1) and phosphate starvation
| PRJNA119339 | ENA
Project description:In all bacterial species examined thusfar, small regulatory RNAs (sRNAs) contribute to intricate patterns of genetic regulation. Many of the actions of these nucleic acids are mediated by chaperones such as the Hfq protein, and genetic screens have identified the exoribonuclease polynucleotide phosphorylase (PNPase) as a stabilizer and facilitator of sRNAs in vivo. We observe that the protective and facilitating effects of PNPase in vivo require the RNA-binding KH and S1 domains and the catalytic site, suggesting a requirement for physical interation of the ribonuclease with either the sRNA itself or other RNAs acting upstream of the process. Although purified PNPase can readily degrade sRNAs in vitro, those same substrates, as well as numerous other sRNAs and transcripts, can be co-purified from cells by immunoprecipitation with neither degradation nor modification to the 3â end. Our results indicate that PNPase can bind RNA in two modes in vivo â either destructive or stabilizing, and that there is active flux of RNAs on PNPase so that the stable molecules do not accumulate. In the presence of Hfq, PNPase and sRNA form a ternary complex in which the enzyme plays a non-destructive, structural role, but the complex does not confer protection against the action of RNase E in vitro. Taken together, our results indicate that PNPase, Hfq and additional factors form a protective ribonucleoprotein assembly that stabilizes certain sRNAs and facilitates their activities. Using cells from the same original culture, immunoprecipitiations using the anti-FLAG M2 resin were performed in the presence or absence of tungstate. Total RNA and immunoprecipitated RNA were sequenced from two independent biological replicates. The number of normalized reads (RPKM) were compared between the total RNA (input) and the immunoprecipitated RNA (output).
2016-01-13 | E-GEOD-69856 | biostudies-arrayexpress
Project description:Gene Expression Signature of Human Polynucleotide Phosphorylase (hPNPaseold-35) in Melanoma
| PRJNA202925 | ENA
Project description:In all bacterial species examined thusfar, small regulatory RNAs (sRNAs) contribute to intricate patterns of genetic regulation. Many of the actions of these nucleic acids are mediated by chaperones such as the Hfq protein, and genetic screens have identified the exoribonuclease polynucleotide phosphorylase (PNPase) as a stabilizer and facilitator of sRNAs in vivo. We observe that the protective and facilitating effects of PNPase in vivo require the RNA-binding KH and S1 domains and the catalytic site, suggesting a requirement for physical interation of the ribonuclease with either the sRNA itself or other RNAs acting upstream of the process. Although purified PNPase can readily degrade sRNAs in vitro, those same substrates, as well as numerous other sRNAs and transcripts, can be co-purified from cells by immunoprecipitation with neither degradation nor modification to the 3’ end. Our results indicate that PNPase can bind RNA in two modes in vivo – either destructive or stabilizing, and that there is active flux of RNAs on PNPase so that the stable molecules do not accumulate. In the presence of Hfq, PNPase and sRNA form a ternary complex in which the enzyme plays a non-destructive, structural role, but the complex does not confer protection against the action of RNase E in vitro. Taken together, our results indicate that PNPase, Hfq and additional factors form a protective ribonucleoprotein assembly that stabilizes certain sRNAs and facilitates their activities.
2016-01-13 | GSE69856 | GEO
Project description:Expression profiles of wild-type and SgrR mutant E. coli strains under aMG and 2-DG-induced stress. Expression profiles of E. coli overexpressing SgrS sRNA.
2013-03-26 | GSE45443 | GEO
Project description:Human Polynucleotide Phosphorylase (hPNPaseold-35) is an evolutionarily conserved 3’→5’ exoribonuclease implicated in the regulation of numerous physiological processes like maintenance of mitochondrial homeostasis, mtRNA import and aging-associated inflammation. From an RNase perspective, little is known about the RNA or miRNA species it targets for degradation or whose expression it regulates; except for c-myc and miR-221. To further elucidate the functional implications of hPNPaseold-35 in cellular physiology, we knocked-down and overexpressed hPNPaseold-35 in melanoma cells and performed gene expression analyses to identify differentially expressed transcripts. Biological triplicates were run on microarrays.
2013-07-30 | E-GEOD-46884 | biostudies-arrayexpress
Project description:Human Polynucleotide Phosphorylase (hPNPaseold-35) is an evolutionarily conserved 3’?5’ exoribonuclease implicated in the regulation of numerous physiological processes like maintenance of mitochondrial homeostasis, mtRNA import and aging-associated inflammation. From an RNase perspective, little is known about the RNA or miRNA species it targets for degradation or whose expression it regulates; except for c-myc and miR-221. To further elucidate the functional implications of hPNPaseold-35 in cellular physiology, we knocked-down and overexpressed hPNPaseold-35 in melanoma and HeLa cells, respectively, and performed gene expression analyses to identify differentially expressed transcripts. Biological triplicates were run on microarrays.
2014-06-01 | E-GEOD-53604 | biostudies-arrayexpress