Compositions and methods for regulating peptidyltransferase activity and uses thereof

Abstract

The present invention provides compositions and means to identify compositions that increase −1 PRF programmed ribosomal frameshift (−1PRF) efficiencies and/or decrease peptidyltransferase activity in a cell, and thus directly affect viral replication or assembly of viral particles. Compositions identified in accordance with the invention specifically inhibit the interaction between ribosomal protein L41 and the ribosomes thereby resulting in decreased peptidyltransferase activity of the ribosomes. Decreases in peptidyltransferase activity have been associated with increased −1 PRF efficiencies, which in turn interfere with self assembly of −1PRF dependent viruses thereby interfering with virus propagation. Compositions in accordance with the invention are useful as antiviral therapeutics for treating a viral infection in a patient.

1 . A method of identifying a composition which inhibits peptidyl transferase activity by inhibiting the interaction of L41 with ribosomes, comprising the steps of: 
 a) contacting a test composition with a cell, cell extract, or purified cell components containing L41 and ribosomes;    b) detecting whether the test composition specifically inhibits the interaction of L41 with the ribosomes; and    c) determining whether the test composition inhibits peptidyl transferase activity of the ribosomes.    
     
     
         2 . The method of  claim 1  wherein the cell or cell extract is from yeast.  
     
     
         3 . The method of  claim 1  wherein the determining step comprises detecting a decrease in the rate of peptidylpuromycin formation by the ribosomes.  
     
     
         4 . A composition identified in accordance with the method of  claim 1 .  
     
     
         5 . A method of inhibiting peptidyl transferase activity in a cell comprising contacting the cell with a composition of  claim 4 .  
     
     
         6 . A method of inhibiting a viral infection in a cell comprising contacting the cell with an effective amount of a composition of  claim 4 .  
     
     
         7 . A method of treating a viral infection in a patient comprising administering to the patient, a therapeutically effective amount of a composition of  claim 4 .  
     
     
         8 . A pharmaceutical composition comprising the composition of  claim 4  and a pharmaceutically acceptable carrier.  
     
     
         9 . A method of identifying a composition which increases −1PRF efficiencies by inhibiting the interaction of L41 with ribosomes comprising the steps of: 
 a) contacting a test composition with a cell, cell extract, or purified cell components, containing L41 and ribosomes;    b) detecting whether the test composition inhibits the interaction of L41 with the ribosomes; and    c) determining whether the test composition increases −1PRF efficiencies of the ribosomes.    
     
     
         10 . The method of  claim 9  wherein the host cell is a yeast cell.  
     
     
         11 . The method of  claim 9  wherein the determining step comprises an assay of programmed ribosomal frameshifting.  
     
     
         12 . A composition identified in accordance with the method of  claim 9 .  
     
     
         13 . A method of increasing −1PRF efficiencies in a cell comprising contacting the cell with a composition of  claim 12 .  
     
     
         14 . A method of inhibiting a viral infection in a cell comprising contacting the cell with an effective amount of a composition of  claim 12 .  
     
     
         15 . A method of treating a viral infection in a patient comprising administering to the patient, a therapeutically effective amount of a composition of  claim 12 .  
     
     
         16 . A pharmaceutical composition comprising the composition of  claim 12  and a pharmaceutically acceptable carrier.  
     
     
         17 . A composition which inhibits the interaction of L41 with ribosomes and thereby decreases peptidyl transferase activity.  
     
     
         18 . The composition of  claim 17  comprising a small molecule.  
     
     
         19 . A pharmaceutical composition comprising the composition of  claim 17  and a pharmaceutically acceptable carrier.  
     
     
         20 . A method for treating a viral infection in a patient comprising administering to the patient a therapeutically effective amount of a pharmaceutical composition of  claim 19.