Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2005-5-5
pubmed:abstractText
GB virus type C (GBV-C) causes persistent infection in humans, although the mechanism by which the virus avoids clearance by the host is unknown. To determine if amino acid polymorphisms in the GB virus type C (GBV-C) NS5A and E2 proteins alter response to interferon (IFN) therapy, we studied the sequence of GBVC NS5A and E2 obtained from people receiving IFN therapy. In addition, we expressed recombinant GBVC NS5A protein to determine if it interferes with RNA-activated protein kinase (PKR) function in vitro. GBVC NS5A amplified from a person whose virus was cleared by IFN therapy (IFN sensitive) demonstrated unique amino acid changes occurring in the region that aligns with the hepatitis C virus (HCV) IFN sensitivity-determining region (ISDR) compared with NS5A sequences from individuals who did not clear GBV-C (IFN resistant). There were no differences in the E2 sequences obtained from IFN-sensitive and IFN-resistant isolates. Using a yeast genetic system, IFN-resistant NS5A inhibited PKR-mediated phosphorylation of eukaryotic initiation factor 2alpha (eIF2alpha) in yeast, whereas IFN-sensitive NS5A did not inhibit PKR function. GBV-C NS5A amino acid polymorphisms appear to be involved in response to IFN therapy, and IFN-resistant GBV-C NS5A inhibited PKR-mediated eIF2alpha phosphorylation in a yeast genetic system, suggesting a mechanism by which GBV-C may evade clearance by naturally occurring host antiviral responses.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1079-9907
pubmed:author
pubmed:issnType
Print
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
261-70
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:15871663-Amino Acid Sequence, pubmed-meshheading:15871663-Base Sequence, pubmed-meshheading:15871663-DNA, Viral, pubmed-meshheading:15871663-Drug Resistance, Viral, pubmed-meshheading:15871663-Eukaryotic Initiation Factor-2, pubmed-meshheading:15871663-Flaviviridae Infections, pubmed-meshheading:15871663-GB virus C, pubmed-meshheading:15871663-Gene Expression, pubmed-meshheading:15871663-Hepatitis, Viral, Human, pubmed-meshheading:15871663-Hepatitis C, Chronic, pubmed-meshheading:15871663-Humans, pubmed-meshheading:15871663-Interferon Type I, pubmed-meshheading:15871663-Molecular Sequence Data, pubmed-meshheading:15871663-Phosphorylation, pubmed-meshheading:15871663-Polymorphism, Genetic, pubmed-meshheading:15871663-Recombinant Proteins, pubmed-meshheading:15871663-Sequence Homology, Amino Acid, pubmed-meshheading:15871663-Two-Hybrid System Techniques, pubmed-meshheading:15871663-Viral Nonstructural Proteins, pubmed-meshheading:15871663-eIF-2 Kinase
pubmed:year
2005
pubmed:articleTitle
GB virus type C NS5A sequence polymorphisms: association with interferon susceptibility and inhibition of PKR-mediated eIF2alpha phosphorylation.
pubmed:affiliation
Department of Internal Medicine and Research, Iowa City VA Medical Center and University of Iowa, Iowa City, IA 52242, USA.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural