Optimizing Luciferase Protein Fragment Complementation for Bioluminescent Imaging of Protein–Protein Interactions in Live Cells and Animals

Publisher Summary This chapter discusses the optimization of luciferase protein fragment complementation for bioluminescent imaging of protein–protein interactions in live cells and animals. Protein–protein interactions regulate a variety of cellular functions, including cell cycle progression, signal transduction, and metabolic pathways. The strategies for detecting protein-binding partners using conventional cell biology assays with the intent of identifying properties that might be exploited for imaging applications are presented. Two-hybrid systems exploit the modular nature of transcription factors, many of which can be separated into discrete DNA-binding and activation domains. Protein–fragment complementation assays depend on the division of a monomeric reporter enzyme into two separate inactive components that can reconstitute function upon association. Luciferase complementation imaging of protein interactions in cells and small animal models has been developed to permit the rapid and repetitive measurement of protein pairs of interest. It is found that optimized luciferase complementation, quantified by imaging with a charge coupled device camera, equipped with appropriate software, can provide an accurate measure of relative protein association in animals and quantitative measurement of protein association in live cells.