Western blot using H1834-69 shows detection of a band at~90kD corresponding to Hsp90 in various lysate preparations (arrowhead). Cos7 transfected with mutant K294R Hsp90 (left two lanes), Cos7 transfected with wild type Hsp90 (middle two lanes) and empty vector Cos7 cells (right two lanes) were either treated with Trichostatin A (an HDAC inhibitor) or mock treated with DMSO only, as indicated. Transfected cells express either mutant or wt Hsp90 coupled to FlagTM tag. Anti-FlagTM immunoprecipitation was performed prior to western blotting with Hsp90.