FIGURE 5.

Hsp31 interacts with Hsp104 and deletion of HSP31 does not alter Hsp104's thermotolerance response. (A) HSP31 deletion does not impair Hsp104's function in thermotolerance. Exponentially growing cells of the [PSI⁺] hsp31Δ and [PSI⁺] strains were drawn from the culture and decimal serial dilutions were plated onto YPD plates and incubated for 2 d at 30°C in each case. Both strains showed a comparable basal tolerance (top right image) and induced tolerance after pretreatment at 37°C (bottom right image) for 30 min to a 50°C heat shock treatment. Left images are non-treated cultures that serve as control. (B) Endogenous level of Hsp104 was determined in exponentially growing cultures of [PSI⁺] hsp31Δ and [PSI⁺] strains in YPD media using Hsp104 specific antibody. (C) Immunoprecipitation of Hsp31 from HSP31-9myc strain with overexpression of Hsp104 either under GPD or GAL promoter, using anti-myc antibody followed by immunoblotting with anti-Hsp104 antibody. Middle panel shows the successful pull down of Hsp31-9myc in all strains using anti-myc antibody. The lower panel Hsp104 was immunoprecipitated using anti-Hsp104 antibody followed by immunoblotting with anti-myc antibody. Equal amount of cells lysates were loaded in each lane.