Analyzing MRNA-protein Complexes Using a Yeast Three-hybrid System

RNA-protein interactions are essential for the proper execution and regulation of every step in the life of a eukaryotic mRNA. Here we describe a three-hybrid system in which RNA-protein interactions can be analyzed using simple phenotypic or enzymatic assays in Saccharomyces cerevisiae. The system can be used to detect or confirm an RNA-protein interaction, to analyze RNA-protein interactions genetically, and to discover new protein or RNA partners when only one is known. Multicomponent complexes containing more than one protein can be detected, identified, and analyzed. We describe the method and how to use it, and discuss applications that bear particularly on eukaryotic mRNAs.