Co-immunoprecipitation in Yeast

Abstract

This protocol describes investigation of protein-protein interactions in baker yeast by co-immunoprecipitation (CoIP). CoIP is a technique to identify physiologically relevant protein-protein interactions in the cell. The interesting protein can be isolated out of solution using antibody that specifically binds to that particular protein (antigene protein). The partner proteins that are bound to a specific target protein can be co-immunoprecipitated together with an antigen. These protein complexes can then be analyzed to identify new binding partners, binding affinities, the kinetics of binding and the function of the target protein. Here I describe the protocols that allow to immunoprecipitate different protein complexes, for example NAC complex (Panasenko et al., 2009), Ccr4-Not complex (Panasenko and Collort, 2011), ribosomes (Panasenko and Collort, 2012) and investigate their partners. For each CoIP I used the different lysis buffer, as indicated below in recipes.