A ribonuclease specific for inosine-containing RNA: a potential role in antiviral defence?

5' exonuclease generating 5'-NMPs as products. The presence of alternative unconventional nucleotides in RNA does not result in degradation unless inosine residues are also present. We show that I-RNase is able to degrade RNAs that previously have been modified by the RED-1 double-stranded RNA adenosine deaminase (dsRAD). dsRADs destabilize dsRNA by converting adenosine to inosine, and some of these enzymes are interferon inducible. We therefore speculate that I-RNase in concert with dsRAD may form part of a novel cellular antiviral defence mechanism that acts to degrade dsRNA. -->

ISSN:	1460-2075
DOI:	10.1093/emboj/16.8.2140
Přístupová URL adresa:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::1574247584588703444a1c48067fb27d https://doi.org/10.1093/emboj/16.8.2140
Rights:	OPEN
Přírůstkové číslo:	edsair.doi.dedup.....1574247584588703444a1c48067fb27d
Autor:	Christopher W.J. Smith, A. D. J. Scadden
Rok vydání:	1997
Předmět:	Exonuclease RNA Stability Adenosine Deaminase Swine Molecular Sequence Data RNA-binding protein General Biochemistry Genetics and Molecular Biology Substrate Specificity Adenosine deaminase medicine Animals Magnesium RNA Messenger Ribonuclease Inosine Molecular Biology RNA Double-Stranded Sheep Base Sequence General Immunology and Microbiology biology General Neuroscience Uterus Brain RNA-Binding Proteins RNA Muscle Smooth Kinetics RNA silencing Biochemistry Exoribonucleases biology.protein RNA Viral Female Research Article medicine.drug
Zdroj:	The EMBO Journal. 16:2140-2149
ISSN:	1460-2075
DOI:	10.1093/emboj/16.8.2140
Popis:	RNA transcripts in which all guanosine residues are replaced by inosine are degraded at a highly accelerated rate when incubated in extracts from HeLa cells, sheep uterus or pig brain. We report here the partial purification and characterization of a novel ribonuclease, referred to as I-RNase, that is responsible for the degradation of inosine-containing RNA (I-RNA). I-RNase is Mg2+ dependent and specifically degrades single-stranded I-RNA. Comparison of the Km of the enzyme for I-RNA with the Ki for inhibition by normal RNA suggests a approximately 300-fold preferential binding to I-RNA, which can account for the specificity of degradation. The site of cleavage by I-RNase is non-specific; I-RNase acts as a 3'-->5' exonuclease generating 5'-NMPs as products. The presence of alternative unconventional nucleotides in RNA does not result in degradation unless inosine residues are also present. We show that I-RNase is able to degrade RNAs that previously have been modified by the RED-1 double-stranded RNA adenosine deaminase (dsRAD). dsRADs destabilize dsRNA by converting adenosine to inosine, and some of these enzymes are interferon inducible. We therefore speculate that I-RNase in concert with dsRAD may form part of a novel cellular antiviral defence mechanism that acts to degrade dsRNA.
Databáze:	OpenAIRE
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