Patent ID: 6852906

Claim:
A method of measuring an activity of a cellular protein-modifying enzyme comprising: obtaining a transgenic nonhuman organism whose genome comprises one or more nucleic acid constructs comprising a transgene encoding a fusion protein comprising a binding domain fused to a first detectable label and a transgene encoding a fusion protein comprising a binding partner of the binding domain fused to a second detectable label operably linked to a promoter, wherein expression of the transgenes result in production of the fusion proteins; and detecting the interaction between the binding domain and the binding partner of said fusion proteins by measuring changes in a physical characteristic of said labels in one or more cells of the transgenic organism; wherein (i) the binding domain and/or binding partner comprise a site subject to post-translational modification by a cellular protein-modifying enzyme; (ii) modification of the site by the enzyme affects the interaction between the binding domain and binding partner; and (iii) the detectable labels fused to the binding domain and binding partner are such that when the binding domain and binding partner interact, a change in said physical characteristic is detected by measuring an alteration of one or both of the labels.