Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The phosphorylation and transcriptional competence of the free cytoplasmic form and the virion form of NS protein of vesicular stomatitis virus (VSV-Indiana/Mudd-Summers) were compared. NS protein is known to exist in two distinct phosphorylated states, NS1 and NS2, that are resolvable by gel electrophoresis. In vitro phosphorylation of virion NS protein by the viral L protein-associated protein kinase resulted in the phosphorylation of both NS1 and NS2. However, in the presence of the N-RNA complex, the NS2 form was preferentially phosphorylated. A cellular protein kinase activity, found in cytoplasmic extracts from VSV-infected or uninfected cells, preferentially phosphorylated NS1, which did not undergo dephosphorylation by cellular phosphatase and also did not convert to NS2. In contrast, the virion or cellular NS2 which had been phosphorylated in vivo or in vitro could be rapidly dephosphorylated by a cellular phosphatase. Cytoplasmic NS protein was found to be fully capable of binding to the virion N-RNA template, and in conjunction with L protein, it participated in synthesis of the leader RNA and five mRNA species of VSV. Moreover, under these conditions, neither cellular phosphatase nor cellular ribonuclease was able to bind to reconstituted nucleocapsids. Binding of cytoplasmic NS to the virion N-RNA template in the presence of L protein resulted in a large and preferential enhancement of NS2 phosphorylation. A protein kinase activity, which phosphorylated NS protein in vitro, was found to be associated with the N-RNA template. This activity appeared to be very tightly bound to N-RNA and exhibited absolute specificity for NS protein of the homologous serotype.
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PMID:Phosphoprotein NS of vesicular stomatitis virus: phosphorylated states and transcriptional activities of intracellular and virion forms. 302 Jul 80

The non-structural protein NS2 of Bluetongue virus (BTV) is synthesized abundantly in virus-infected cells and has been suggested to be involved in virus replication. The protein, with a high content of charged residues, possesses a strong affinity for single-stranded RNA species but, to date, all studies have failed to identify any specificity in the NS2-RNA interaction. In this report, we have examined, through RNA binding assays using highly purified NS2, the specificity of interaction with different single-stranded RNA (ssRNA) species in the presence of appropriate competitors. The data obtained show that NS2 indeed has a preference for BTV ssRNA over nonspecific RNA species and that NS2 recognizes a specific region within the BTV10 segment S10. The secondary structure of this region was determined and found to be a hairpin-loop with substructures within the loop. Modification-inhibition experiments highlighted two regions within this structure that were protected from ribonuclease cleavage in the presence of NS2. Overall, these data imply that a function of NS2 may be to recruit virus messenger RNAs (that also act as templates for synthesis of genomic RNAs) selectively from other RNA species within the infected cytosol of the cell during virus replication.
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PMID:Sequence specificity in the interaction of Bluetongue virus non-structural protein 2 (NS2) with viral RNA. 1279 83