One MAPKKK tagged with the myc epitope and the other tagged with HATAP were exposed to osmostress of 0.6 M KCl (B) or oxidative stress of 0.73 mM H2O2 (C), and their cell lysate was subjected to affinity purification with IgG epharose, followed by immunoblotting with anti-myc and anti-HA antibodies. The strains expressing no HATAP-tagged MAPKKK served as negative controls (wis4+ and win1+). Bottom