Fifteen years of the yeast three-hybrid system: RNA–protein interactions under investigation

In 1996, the Wickens and the Kuhl labs developed the yeast three-hybrid system independently. By expressing two chimeric proteins and one chimeric RNA molecule in Saccharomyces cerevisiae, this method allows in vivo monitoring of RNA–protein interactions by measuring the expression levels of HIS3 and LacZ reporter genes. Specific RNA targets have been used to characterize unknown RNA binding proteins. Previously described RNA binding proteins have also been used as bait to select new RNA targets. Finally, this method has been widely used to investigate or confirm previously suspected RNA–protein interactions. However, this method falls short in some aspects, such as RNA display and selection of false positive molecules. This review will summarize the results obtained with this method from the past 15 years, as well as on recent efforts to improve its specificity.