Figure 2. Sp_Hsp104 is required for thermotolerance in S. pombe.

(A) The Sp_hsp104⁺ gene is heat-inducible. WT (SP3220) and Δhsp104 (SP12422) S. pombe cells were treated or not for 1 hour at 37°C. Cell extracts were separated by SDS-PAGE, transferred onto a nitrocellulose membrane and immunoblotted with rabbit polyclonal antibodies against Sc_Hsp104 [6]. Immunoblot against tubulin is shown as a loading control. (B) The Sp_hsp104⁺ gene is required for thermotolerance. WT (SP3220) and Δhsp104 (SP12422) S. pombe cells were submitted to a thermotolerance assay. Pre-treatment of 1 hour at 37°C was applied or not before heat shock at 50°C for 20 minutes. Cells were then briefly cooled on ice, serially diluted (10⁻¹, 10⁻², 10⁻³, 10⁻⁴), spotted on minimal media and incubated for 5 days at 30°C. Results are representative of three independent experiments.