Interaction-Based Cloning of Novel Proteins

Abstract

It has become evident that interactions between proteins are the underlying mechanism of basic biological processes such as signal transduction, transcription, cell cycle progression, etc. For example, during the cell cycle, members of the Cdk family differentially interact with a number of cyclin regulatory subunits resulting in functionally distinct kinase complexes that regulate different stages of cell cycle progression (Draetta 1990; Sherr 1993). The cyclin/Cdk complexes contain other proteins that regulate their kinase activity (Xiong et al. 1993). Since these proteins form stable complexes, they are extremely amenable to interaction-based cloning using the two-hybrid system. The power of this approach has been well demonstrated recently by the interaction cloning of a battery of new cell cycle regulators such as p16^Ink4 (Serrano et al. 1993), p21^Cip1 (Harper et al. 1993), p130 (Hannon et al. 1993), and Cdi1l/Kap (Gyuris et al. 1993; Hannon et al. 1994). In most cases, their presence in cyclin/cdk complexes had been detected previously by immunoprecipitation (Xiong et al. 1993).