Abstract
Hepatitis C virus (HCV) causes chronic hepatitis leading to liver fibrosis and autoimmune diseases. AIMP1/p43 is a multifunctional protein initially known as a cofactor of aminoacyl tRNA synthetase complex. Its function includes negative regulation of TGF-β signaling and suppression of Lupus-like autoimmune disease by inhibition of surface expression of gp96. HCV E2 was shown to directly interact with AIMP1/p43 by GST pulldown assay and coimmunoprecipitation. Their subcellular colocalization was observed in an immunofluorescence confocal microscopy. We showed that HCV E2 led to degradation of AIMP1/p43 in two ways. First, in the presence of HCV E2, endogenous AIMP1/p43 was shown to be degraded in an ubiquitin-dependent proteasome pathway. Second, grp78, an ER chaperone, was shown to interact with and stabilize AIMP1/p43. And HCV E2 inhibited this interaction leading to reduction of cellular AIMP1/p43. The degradation of AIMP1/p43 by HCV E2 resulted in increase of TGF-β signaling and cell surface expression of gp96. Thus we suggest that these are novel mechanisms responsible for liver fibrosis and autoimmune diseases caused by HCV.
Original language | English |
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Article number | e96302 |
Journal | PloS one |
Volume | 9 |
Issue number | 5 |
DOIs | |
Publication status | Published - 2014 May 9 |
All Science Journal Classification (ASJC) codes
- Biochemistry, Genetics and Molecular Biology(all)
- Agricultural and Biological Sciences(all)
- General