Back to Search
Start Over
HCV NS5A protein containing potential ligands for both Src homology 2 and 3 domains enhances autophosphorylation of Src family kinase Fyn in B cells
- Source :
- PLoS ONE, Vol 7, Iss 10, p e46634 (2012), PLoS ONE
- Publication Year :
- 2012
- Publisher :
- Public Library of Science (PLoS), 2012.
-
Abstract
- Hepatitis C virus (HCV) infects B lymphocytes and induces mixed cryoglobulinemia and B cell non-Hodgkin's lymphoma. The molecular mechanism for the pathogenesis of HCV infection-mediated B cell disorders remains obscure. To identify the possible role for HCV nonstructural 5A (NS5A) protein in B cells, we generated the stable B cell lines expressing Myc-His tagged NS5A. Immunoprecipitation study in the presence or absence of pervanadate (PV) implied that NS5A was tyrosine phosphorylated by pervanadate (PV) treatment of the cells. Therefore we examined pull-down assay by using glutathione S-transferase (GST)-fusion proteins of various Src homology 2 (SH2) domains, which associates with phosphotyrosine within a specific amino acid sequence. The results showed that NS5A specifically bound to SH2 domain of Fyn from PV-treated B cells in addition to Src homology 3 (SH3) domain. Substitution of Arg(176) to Lys in the SH2 domain of Fyn abrogated this interaction. Deletion mutational analysis demonstrated that N-terminal region of NS5A was not required for the interaction with the SH2 domain of Fyn. Tyr(334) was identified as a tyrosine phosphorylation site in NS5A. Far-western analysis revealed that SH2 domain of Fyn directly bound to NS5A. Fyn and NS5A were colocalized in the lipid raft. These results suggest that NS5A directly binds to the SH2 domain of Fyn in a tyrosine phosphorylation-dependent manner. Lastly, we showed that the expression of NS5A in B cells increased phosphorylation of activation loop tyrosine in the kinase domain of Fyn. NS5A containing ligand for both SH2 and SH3 domains enhances an aberrant autophosphorylation and kinase activity of Fyn in B cells.
- Subjects :
- B Cells
Gastroenterology and hepatology
Immune Cells
viruses
Immunology
lcsh:Medicine
Viral diseases
Viral Nonstructural Proteins
Biology
Ligands
Proto-Oncogene Proteins c-fyn
SH2 domain
Polymerase Chain Reaction
environment and public health
Hepatitis
src Homology Domains
FYN
Cell Line, Tumor
Molecular Cell Biology
Tyrosine Kinase Signaling Cascade
Humans
Src family kinase
Phosphorylation
lcsh:Science
Liver diseases
DNA Primers
B-Lymphocytes
Multidisciplinary
Tyrosine-protein kinase CSK
Base Sequence
Autophosphorylation
lcsh:R
virus diseases
biochemical phenomena, metabolism, and nutrition
Hepatitis C
Molecular biology
Signaling Cascades
digestive system diseases
Infectious hepatitis
Protein kinase domain
Medicine
Infectious diseases
Clinical Immunology
lcsh:Q
Tyrosine kinase
Research Article
Signal Transduction
Proto-oncogene tyrosine-protein kinase Src
Subjects
Details
- Language :
- English
- ISSN :
- 19326203
- Volume :
- 7
- Issue :
- 10
- Database :
- OpenAIRE
- Journal :
- PLoS ONE
- Accession number :
- edsair.doi.dedup.....08fbf793a52ca000c862765079691ed1