TY - JOUR
T1 - The ORF3 Protein of Hepatitis E Virus Binds to Src Homology 3 Domains and Activates MAPK
AU - Korkaya, Hasan
AU - Jameel, Shahid
AU - Gupta, Dinesh
AU - Tyagi, Shweta
AU - Kumar, Ravinder
AU - Zafrullah, Mohammad
AU - Mazumdar, Manjari
AU - Lal, Sunil Kumar
AU - Xiaofang, Li
AU - Sehgal, Deepak
AU - Das, Suman Ranjan
AU - Sahal, Dinkar
PY - 2001/11/9
Y1 - 2001/11/9
N2 - The hepatitis E virus (HEV) is the causative agent of hepatitis E, an acute form of viral hepatitis. The biology and pathogenesis of HEV remain poorly understood. We have used in vitro binding assays to show that the HEV ORF3 protein (pORF3) binds to a number of cellular signal transduction pathway proteins. This includes the protein tyrosine kinases Src, Hck, and Fyn, the p85α regulatory subunit of phosphatidylinositol 3-kinase, phospholipase Cγ, and the adaptor protein Grb2. A yeast two-hybrid assay was used to further confirm the pORF3-Grb2 interaction. The binding involves a proline-rich region in pORF3 and the src homology 3 (SH3) domains in the cellular proteins. Competition assays and computer-assisted modeling was used to evaluate the binding surfaces and interaction energies of the pORF3-SH3 complex. In pORF3-expressing cells, pp60src was found to associate with an 80-kDa protein, but no activation of the Src kinase was observed in these cells. However, there was increased activity and nuclear localization of ERK in the pORF3-expressing cells. These studies suggest that pORF3 is a viral regulatory protein involved in the modulation of cell signaling. The ORF3 protein of HEV appears to be the first example of a SH3 domain-binding protein encoded by a virus that causes an acute and primarily self-limited infection.
AB - The hepatitis E virus (HEV) is the causative agent of hepatitis E, an acute form of viral hepatitis. The biology and pathogenesis of HEV remain poorly understood. We have used in vitro binding assays to show that the HEV ORF3 protein (pORF3) binds to a number of cellular signal transduction pathway proteins. This includes the protein tyrosine kinases Src, Hck, and Fyn, the p85α regulatory subunit of phosphatidylinositol 3-kinase, phospholipase Cγ, and the adaptor protein Grb2. A yeast two-hybrid assay was used to further confirm the pORF3-Grb2 interaction. The binding involves a proline-rich region in pORF3 and the src homology 3 (SH3) domains in the cellular proteins. Competition assays and computer-assisted modeling was used to evaluate the binding surfaces and interaction energies of the pORF3-SH3 complex. In pORF3-expressing cells, pp60src was found to associate with an 80-kDa protein, but no activation of the Src kinase was observed in these cells. However, there was increased activity and nuclear localization of ERK in the pORF3-expressing cells. These studies suggest that pORF3 is a viral regulatory protein involved in the modulation of cell signaling. The ORF3 protein of HEV appears to be the first example of a SH3 domain-binding protein encoded by a virus that causes an acute and primarily self-limited infection.
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U2 - 10.1074/jbc.M101546200
DO - 10.1074/jbc.M101546200
M3 - Article
C2 - 11518702
AN - SCOPUS:0035834641
SN - 0021-9258
VL - 276
SP - 42389
EP - 42400
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 45
ER -