Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.27.3 (RNase T1)
 1,228 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A role for the Epstein-Barr virus small RNA species EBER-1 in the regulation of protein synthesis has been investigated in the reticulocyte-lysate cell-free translation system. Recombinant EBER-1 was synthesized by in vitro transcription of a plasmid containing the viral gene and purified by CF11-cellulose chromatography and ribonuclease III treatment. When added to the reticulocyte lysate at 10-20 micrograms/ml or more, EBER-1 prevents the inhibition of protein synthesis caused by low concentrations of synthetic double-stranded RNA, poly(I).poly(C). This effect is eliminated by treatment of the recombinant EBER-1 with ribonuclease T1. Disruption of the secondary structure of EBER-1 by substitution of inosine for guanosine in the in-vitro-synthesized RNA impairs the ability of EBER-1 to prevent the poly(I).poly(C)-mediated inhibition of protein synthesis. These results suggest that high concentrations of EBER-1 regulate protein synthesis by blocking the activation of the double-stranded RNA-dependent eukaryotic initiation factor 2 alpha (eIF-2 alpha) protein kinase DAI (p68), and that this property is dependent on the secondary structure of the small RNA molecule.
 ...
PMID:Translational control by the Epstein-Barr virus small RNA EBER-1. Reversal of the double-stranded RNA-induced inhibition of protein synthesis in reticulocyte lysates. 217 60

A direct, ribonuclease T1 protection assay was employed to study the binding of a delta agent genomic RNA transcript containing the conserved domain to the double-stranded RNA- (dsRNA-) dependent protein kinase of mammalian cells, PKR (also known as DAI, p1-elF2, or p68 kinase). In a control reaction, this assay identified a major portion of the same PKR binding site in VA RNA as deduced previously using a footprinting technique (Clarke PA, Mathews MB, 1995, RNA 1:1-20). Although delta agent RNA contains extensive secondary structure throughout the conserved region, we found a remarkable specificity in its PKR binding. The same region was protected by intact PKR and by a 184-amino acid fragment thereof containing the two RNA-binding motifs (dsRBMs) but lacking kinase activity. Two specific opposed, continuous segments of delta agent RNA (extending about 65-70 bases) were obtained reproducibly. Each is more than twice as long as those protected in VA RNA (about 25 bases), suggesting the involvement of PKR dimers in delta RNA binding. The PKR-protected region of delta agent RNA also contains a characteristic tertiary structural element that may be involved in binding specificity.
 ...
PMID:Surprising specificity of PKR binding to delta agent genomic RNA. 908 50