Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.27.4 (ribonuclease)
 6,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Programmed cell death (PCD) is executed by proteases, which cleave diverse proteins thus modulating their biochemical and cellular functions. Proteases of the caspase family and hundreds of caspase substrates constitute a major part of the PCD degradome in animals. Plants lack close homologues of caspases, but instead possess an ancestral family of cysteine proteases, metacaspases. Although metacaspases are essential for PCD, their natural substrates remain unknown. Here we show that metacaspase mcII-Pa cleaves a phylogenetically conserved protein, TSN (Tudor staphylococcal nuclease), during both developmental and stress-induced PCD. TSN knockdown leads to activation of ectopic cell death during reproduction, impairing plant fertility. Surprisingly, human TSN (also known as p100 or SND1), a multifunctional regulator of gene expression, is cleaved by caspase-3 during apoptosis. This cleavage impairs the ability of TSN to activate mRNA splicing, inhibits its ribonuclease activity and is important for the execution of apoptosis. Our results establish TSN as the first biological substrate of metacaspase and demonstrate that despite the divergence of plants and animals from a common ancestor about one billion years ago and their use of distinct PCD pathways, both have retained a common mechanism to compromise cell viability through the cleavage of the same substrate, TSN.
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PMID:Tudor staphylococcal nuclease is an evolutionarily conserved component of the programmed cell death degradome. 1982 Jul 3

The latent ribonuclease RNase L and the interferon-inducible 2',5'-oligoadenylate synthetase (OAS) have been implicated in the antiviral response against hepatitis C virus (HCV). However, the specific roles of these enzymes against HCV have not been fully elucidated. In this study, a scarce endogenous expression and RNA degrading activity of RNase L in human hepatoma Huh7 cells enabled us to demonstrate the antiviral activity of RNase L against HCV replication through the transient expression of the enzyme. The antiviral potential of specific members of the OAS family was further examined through overexpression and RNA interference approaches. Our data suggested that among the members of the OAS family, OAS1 p46 and OAS3 p100 mediate the RNase L-dependent antiviral activity against HCV.
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PMID:The ribonuclease L-dependent antiviral roles of human 2',5'-oligoadenylate synthetase family members against hepatitis C virus. 2319 81