Protein-protein interactions play fundamental roles in many biological proc
esses. Hence, protein interaction mapping is becoming a well-established fu
nctional genomics approach to generate functional annotations for predicted
proteins that so far have remained uncharacterized. The yeast two-hybrid s
ystem is currently one of the most standardized protein interaction mapping
techniques. Here, we describe the protocols for a semiautomated, high-thro
ughput, Gal4-based yeast two-hybrid system. (C) 2001 Academic Press.