Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.13.1 (exoribonuclease)
 732 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We examined HeLa cell viability and RNA oxidative damage in response to hydrogen peroxide (H2O2) treatment. The level of damaged RNA, measured by the content of 8-hydroxyguanosine (7,8-dihydro-8-oxoguanosine, 8-oxoG), increases depending on H2O2 dosage and is inversely correlated with cell viability. The elevated level of 8-oxoG in RNA decreases after removal of oxidative challenge, suggesting the existence of surveillance mechanism(s) for cleaning up oxidized RNA. Human polynucleotide phosphorylase (hPNPase), an exoribonuclease primarily located in mitochondria, has been previously shown to bind 8-oxoG-RNA with high affinity. The role of hPNPase in HeLa cell under oxidative stress conditions is examined here. Overexpression of hPNPase reduces RNA oxidation and increases cell viability against H2O2 insult. Conversely, hPNPase knockdown decreases viability and increases 8-oxoG level in HeLa cell exposed to H2O2. Our results suggest that hPNPase plays an important role in protecting cells and limiting damaged RNA under oxidative stress.
 ...
PMID:Human polynucleotide phosphorylase reduces oxidative RNA damage and protects HeLa cell against oxidative stress. 1850 Nov 93

RNA degradation plays important roles for maintaining temporal control and fidelity of gene expression, as well as processing of transcripts. In Saccharomyces cerevisiae the RNA exosome is a major 3'-to-5' exoribonuclease and also has an endonuclease domain of unknown function. Here we report a physiological role for the exosome in response to a stimulus. We show that inactivating the exoribonuclease active site of Rrp44 up-regulates the iron uptake regulon. This up-regulation is caused by increased levels of reactive oxygen species (ROS) in the mutant. Elevated ROS also causes hypersensitivity to H2O2, which can be reduced by the addition of iron to H2O2 stressed cells. Finally, we show that the previously characterized slow growth phenotype of rrp44-exo(-) is largely ameliorated during fermentative growth. While the molecular functions of Rrp44 and the RNA exosome have been extensively characterized, our studies characterize how this molecular function affects the physiology of the organism.
...
PMID:The RNA exosome affects iron response and sensitivity to oxidative stress. 2486 16