Patent ID: 7419780
Filing Date: 2008-09-02
Classification: A61K,C07J,C07K,C12N,G01N

Abstract:
1. A method for identifying a protein target as being able to bind a ligand, comprising: (a) providing a molecule comprising a methotrexate moiety covalently linked to the ligand, which methotrexate moiety binds to a dihydrofolate reductase; (b) introducing the molecule into a cell which i) expresses a first fusion protein comprising the dihydrofolate reductase that binds to the methotrexate moiety, ii) expresses a second fusion protein comprising the protein target, wherein either the first or second fusion protein also comprises a transcription activator domain and the other fusion protein comprises a DNA-binding domain, and iii) has a reporter gene, wherein expression of the reporter gene is conditioned on the proximity of the first fusion protein to the second fusion protein and wherein the DNA-binding domain binds upstream of the reporter gene, and wherein the cell is a yeast cell; (c) permitting the molecule to bind to the first fusion protein and to the second fusion protein so as to activate the expression of the reporter gene; and (d) selecting the cell if it expresses the reporter gene, so as to thereby identify the protein target as being able to bind the ligand.