Biochemical assay to monitor the ubiquitin ligase activities of cullins

Abstract

The present invention is based on the discovery of a simplified assay for identifying modulators of ubiquitin ligase activity. This assay allows detection of compounds that affect ubiquitination and thus, cell cycle regulation in cells. An increase in ubiquitination, in comparison to a test sample lacking a test compound, indicates a stimulation of activity, whereas a reduction in ubiquitination indicates an inhibitor of activity. Also disclosed herein are methods of identifying proteins having ubiquitin ligase activity, methods of identifying substrates for ubiquitination, methods for identifying an activity relationship between a particular ubiquitin ligase and a particular ubiquitin conjugating enzyme, and chimeric proteins comprising a ubiquitin conjugating enzyme and a ubiquitination substrate, which are useful in all of the disclosed methods.

Dependencies are inferred from the claim text.