Hepatitis C virus NS5B truncated protein and methods thereof to identify antiviral compounds

Abstract

The invention provides HCV NS5B polypeptides and DNA (RNA) encoding HCV NS5B polypeptides and methods for producing such polypeptides by recombinant techniques. Also provided are methods for utilizing HCV NS5B polypeptides to screen for antiviral compounds.

What is claimed is:  
     
         1 . An isolated polynucleotide comprising a polynucleotide sequence selected from the group consisting of: 
 (a) a polynucleotide having at least a 95% identity to a polynucleotide encoding a polypeptide comprising the amino acid sequence of SEQ ID NO:4;    (b) a polynucleotide encoding a polypeptide comprising an amino acid sequence which is at least 95% identical to the amino acid sequence of SEQ ID NO:4; and    (c) a polynucleotide which is complementary to the polynucleotide(s) of (a) or (b).    
     
     
         2 . The polynucleotide according to  claim 1  wherein the polynucleotide is DNA.  
     
     
         3 . The polynucleotide according to  claim 1  wherein the polynucleotide is RNA.  
     
     
         4 . An isolated polynucleotide comprising the nucleic acid sequence set forth in SEQ ID NO:3.  
     
     
         5 . The polynucleotide according to  claim 4  comprising nucleotide 11792 to 13562 set forth in SEQ ID NO:3.  
     
     
         6 . An isolated polynucleotide which encodes a polypeptide comprising the amino acid sequence of SEQ ID NO:4.  
     
     
         7 . A vector comprising the polynucleotide according to  claim 1 .  
     
     
         8 . A host cell comprising the vector according to  claim 7 .  
     
     
         9 . A process for producing a polypeptide, which process comprises: expressing from the host cell according to  claim 8  a polypeptide or a fragment encoded by the polynucleotide sequence comprising SEQ ID NO:3 under conditions sufficient for the production of said polypeptide or fragment.  
     
     
         10 . A polypeptide comprising an amino acid sequence which is at least 95% identical to the amino acid sequence according to SEQ ID NO:4.  
     
     
         11 . A polypeptide comprising an amino acid sequence as set forth in SEQ ID NO:4.  
     
     
         12 . An antibody against the polypeptide according to  claim 10 .  
     
     
         13 . An antagonist which inhibits the activity or expression of the polypeptide according to  claim 10 .  
     
     
         14 . A method for identifying compounds which inhibit or which activate an the polypeptide according to  claim 10 , which method comprises: 
 a) contacting a composition comprising the polypeptide with a candidate compound to be screened under conditions to permit interaction between the compound and the polypeptide; and    b) determining whether the compound interacts with, and activates, or inhibits the activity of the polypeptide.    
     
     
         15 . The method according to  claim 14 , wherein the interaction in the contacting step of (a) is associated with a second component capable of providing a detectable signal in response to the interaction of the polypeptide with the compound and wherein the determining step of (b) detects the presence or absence of a signal generated from the interaction of the compound with the polypeptide.  
     
     
         16 . A method for inducing an immunological response in a mammal which method comprises inoculating the mammal with the HCV NS5B polypeptide of  claim 10 , or a fragment or variant thereof, in an effective amount sufficient to produce an antibody and/or T cell immune response in said mammal.  
     
     
         17 . A method of inducing immunological response in a mammal in need thereof, which method comprises delivering a nucleic acid vector, wherein said vector directs expression of the HCV NS5B polypeptide according to  claim 10  or which vector expresses a fragment or a variant of the HCV NS5B polypeptide in vivo in order to induce an immunological response sufficient to produce an antibody and/or T cell immune response in said mammal.  
     
     
         18 . A method of protecting a mammal from a disease caused by viruses of the  Flaviviridae  family, which method comprises adminstering, to said mammal a therapeutically effective amount of an antibody produced against the polypeptide of  claim 10.