FIGURE 2.

RGTA1 and RGTA2 interact with RGTB1 and RGTB2. RGTA1·c-Myc and RGTA2-c-Myc co-immunoprecipitated (IP) with RGTB1-FLAG and RGTB2-FLAG in the yeast cell extracts co-expressing the two subunits. The FLAG-tagged RGTB subunit was pulled down with anti-FLAG beads, and monoclonal anti-c-Myc antibody was used to detect whether the c-Myc-tagged RGTA was pulled down along with FLAG-tagged RGTB. RGTA2-c-Myc alone could not be pulled down by anti-FLAG antibody and thus did not present in the resulting eluate. Input and pull-down samples were resolved with two separate 10% SDS-polyacrylamide gels, and different epitope tags were detected with separate blots and one antibody at a time (see “Experimental Procedures”).