Method and compositions for monitoring dna binding molecules in living cells

Abstract

The present invention provides a method of screening for a compound that binds to a selected nucleic acid comprising contacting compound fluorescently labeled by a fluorescent protein with a cell having a plurality of copies of the nucleic acid in an array such that the nucleic acid can be directly detected when bound by fluorescently labeled compound; and directly detecting the location of fluorescence within the cell, fluorescence aggregated at the site of the nucleic acid array indicating a compound that binds to the selected nucleic acid. In particular compounds such a transcription factors can be screened. Reagents for such method are provided including a mammalian cell having a plurality of steroid receptor response elements in an array such that the response element can be directly detected when bound by fluorescently labeled steroid receptor and a chimeric protein comprising a fluorescent protein fused to a steroid receptor.

1 .- 50 . (canceled) 
     
     
         51 . An isolated nucleic acid encoding the chimeric protein comprising a fluorescent protein fused to a transcription factor. 
     
     
         52 . An isolated nucleic acid encoding the chimeric protein of  claim 51 , wherein the transcription factor is a steroid receptor. 
     
     
         53 . An isolated nucleic acid encoding the chimeric protein of  claim 51 , wherein the fluorescent protein is a green fluorescent protein. 
     
     
         54 . An isolated nucleic acid encoding the chimeric protein of  claim 52 , wherein the steroid receptor is glucocorticoid receptor and a green fluorescent protein is fused to the amino-terminal end of the glucocorticoid receptor. 
     
     
         55 . An isolated nucleic acid encoding the chimeric protein of  claim 54 , wherein the glucocorticoid receptor has a substitution of serine for cysteine 656 and having the amino acid sequence set forth in SEQ ID NO: 2. 
     
     
         56 . An isolated nucleic acid encoding the chimeric protein of  claim 55  having the nucleotide sequence set forth in SEQ ID NO: 1. 
     
     
         57 .- 58 . (canceled)