Methods of modulating mitochondrial nad-dependent deacetylase

Abstract

The present invention provides methods for identifying agents that modulate a level or an activity of a mitochondrial NAD-dependent deacetylase polypeptide, as well as agents identified by the methods. The invention further provides methods of modulating mitochondrial NAD-dependent deacetylase activity in a cell. The invention further provides methods of modulating mitochondrial function by modulating the activity of mitochondrial NAD-dependent deacetylase.

1 . An in vitro method of identifying an agent that modulates an enzymatic activity of a human mitochondrial NAD-dependent deacetylase, the method comprising:
 contacting a mitochondrial NAD-dependent deacetylase polypeptide with a test agent in an assay mixture that comprises NAD and an acetylated histone peptide; and   determining the effect, if any, of the test agent on the enzymatic activity of mitochondrial NAD-dependent deacetylase.   
     
     
         2 . The method of  claim 1 , wherein the human mitochondrial NAD-dependent deacetylase polypeptide comprises an amino acid sequence as set forth in SEQ ID NO:01. 
     
     
         3 . The method of  claim 1 , wherein the acetylated histone peptide comprises amino acids 1-22 of histone 4. 
     
     
         4 . The method of  claim 1 , wherein the acetylated histone peptide contains a  14 C-labeled acetyl group, and determining the effect of the agent on the enzymatic activity of the deacetylase is performed by measuring release of the radioactive acetyl group. 
     
     
         5 . The method of  claim 1 , wherein determining the effect of the agent on the enzymatic activity of the deacetylase is performed by detecting binding of an antibody specific for acetylated histone. 
     
     
         6 . An in vitro method for identifying an agent that modulates a level of mitochondrial NAD-dependent deacetylase in a cell, the method comprising contacting a cell that produces mitochondrial NAD-dependent deacetylase with a test agent; and determining the effect, if any, of the test agent on the level of mitochondrial NAD-dependent deacetylase. 
     
     
         7 . The method of  claim 6 , wherein determining the effect of the agent on the level of the deacetylase is performed by determining a level of mitochondrial NAD-dependent deacetylase mRNA in the cell. 
     
     
         8 . The method of  claim 6 , wherein determining the effect of the agent on the level of the deacetylase is performed by determining a level of mitochondrial NAD-dependent deacetylase polypeptide in the cell. 
     
     
         9 . A biologically active agent identified by a screening method according to  claim 1  or  claim 6 . 
     
     
         10 . A pharmaceutical composition comprising a biologically active agent that reduces a level or an activity of a mitochondrial NAD-dependent deacetylase protein; and a pharmaceutically acceptable excipient. 
     
     
         11 . A method of treating a disorder caused by mitochondrial malfunction or dysfunction in an individual, the method comprising administering to the individual an effective amount of an agent that modulates a level or activity of a mitochondrial NAD-dependent deacetylase protein. 
     
     
         12 . The method of  claim 11 , wherein the level or activity of the mitochondrial NAD-dependent deacetylase protein is increased. 
     
     
         13 . The method of  claim 11 , wherein the level or activity of the mitochondrial NAD-dependent deacetylase protein is decreased.