Sirt4 activities

Abstract

Methods of screening for compounds that modulate the expression or activity of Sirt4 are provided. Also provided are methods of modulating insulin secretion, treating metabolic disorders, and treating neurodegenerative disorders by modulating the expression or activity of Sirt4.

1 . A method of evaluating the effect of a test compound on Sirt4, the method comprising:
 a) providing a reaction mixture comprising Sirt4 and a test compound; and   b) evaluating an activity of Sirt4,
 wherein the activity is interaction with a Sirt4 binding partner and the reaction mixture comprises a binding partner, wherein the binding partner is glutamate dehydrogenase (GDH), adenine nucleotide transporter (ANT), or insulin-degrading enzyme (IDE); or 
 wherein the activity is ADP-ribosyltransferase enzymatic activity and the reaction mixture comprises a substrate of the enzymatic activity and an ADP-ribosyl donor, wherein the substrate of the enzymatic activity is GDH, aldehyde dehydrogenase (ADH), or ANT. 
   
     
     
         2 . The method of  claim 1 , wherein the activity is ADP-ribosyltransferase enzymatic activity. 
     
     
         3 . The method of  claim 1 , wherein the ADP-ribosyl donor comprises NAD or an NAD analog. 
     
     
         4 . The method of  claim 3 , wherein the NAD or NAD analog comprises a radioactive label. 
     
     
         5 . The method of  claim 2 , wherein the substrate of the ADP-ribosyltransferase enzymatic activity is GDH. 
     
     
         6 . The method of  claim 1 , wherein the test compound is a small molecule. 
     
     
         7 . The method of  claim 1 , wherein the method is repeated for each of a plurality of test compounds from a chemical library. 
     
     
         8 . The method of  claim 1 , wherein the Sirt4 comprises a sequence at least 85% identical to SEQ ID NO:3. 
     
     
         9 . The method of  claim 1 , wherein the Sirt4 comprises a sequence at least 85% identical to SEQ ID NO:1 or amino acid residues 29-314, 29-308, 30-314, 36-308, 42-308, 42-300, or 56-314 of SEQ ID NO:1. 
     
     
         10 . The method of  claim 1 , further including the step of comparing the activity evaluated in (b) with the Sirt4 activity evaluated in the absence of the test compound. 
     
     
         11 . The method of  claim 1 , wherein the activity is interaction with a Sirt4 binding partner. 
     
     
         12 . The method of  claim 1 , wherein the test compound is a macromolecule. 
     
     
         13 . The method of  claim 1 , wherein the Sirt4 comprises SEQ ID NO:3. 
     
     
         14 . The method of  claim 1 , wherein the Sirt4 comprises a sequence at least 85% identical to SEQ ID NO:1. 
     
     
         15 . The method of  claim 1 , wherein the Sirt4 comprises a sequence at least 85% identical to amino acid residues 29-314 of SEQ ID NO:1. 
     
     
         16 . The method of  claim 1 , wherein the Sirt4 comprises SEQ ID NO:1. 
     
     
         17 . The method of  claim 1 , wherein the Sirt4 comprises amino acid residues 29-314 of SEQ ID NO:1. 
     
     
         18 . The method of  claim 1 , further including the step of evaluating the test compound in a cellular model of insulin secretion. 
     
     
         19 . The method of  claim 2 , including the step of evaluating the test compound in a cellular model of insulin secretion. 
     
     
         20 . The method of  claim 11 , further including the step of evaluating the test compound in a cellular model of insulin secretion.