Hspb1

Commercially prepared recombinant HSPA1A and HSPB1 (Stressmarq Biosciences, Victoria, Canada) were diluted in 10% HI‐RPMI and added to cells at the final concentrations of 0, 1, 10, 100 and 1000 ng·mL⁻¹. For denatured HSPs (dHSPs—e.g. dHSPA1A and dHSPB1) that aimed at excluding possible contamination, the stock solution was heated by boiling in a water bath at 100 °C for 10 min and allowed to cool before adding them to the cells.

Antibodies (dilutions are indicated in brackets for western blot (WB), immunofluorescence (IF), or immunoprecipitation (IP)) against FLAG (Sigma, clone M2; Sigma, produced in Rabbit, IP 3 μl/sample, IF 1:100, WB 1:1000), FLAG (Sigma, clone M2; Sigma, M, Wb 1:1000, IF 1:200), ubiquityl-histone H2A (Millipore, clone E6C5), ubiquitin (Norvus Biologicals, FK2, M, WB 1:1000, IF 1:1000; Dako WB), K48-linkage specific polyubiquitin (Enzo lifesciences, WB 1:1000), K63-linkage specific polyubiquitin (Cell Signaling, clone D7A11, 1:1000), myc (MBL, clone PL14, WB 1:3000, IF 1:100), HSC70 (Stressgen, WB 1:5000, IF 1:100), LC3B (Novus Biologicals, NB100-220), GFP (clonetech, 632381), p62 (Enzo Life Sciences, BML-PW9860), Lamin A/C (Santa Cruz, 4A58), HSC70 (Stressmarq biosciences), HSP70 (Stressgen, clone SPA-810, WB 1:1000, IF 1:50), HSPA1A (Enzo life sciences, Rb, WB 1:1000), HSPB1 (Stressmarq biosciences), GAPDH (Fitzgerald, clone 6C5, WB 1:50,000), histone H2A (Abcam, WB 1:5000), MYC (Clonetech, Mountain View, CA, USA), and DNAJB1/Hsp40 (Stressgen, San Diego, CA, USA, Rb, 1:1000) were used.
MG132 (20 µM for 3–6 h), rapamycin, Pepstatin A (10 μg/ml), E64d (10 μg/ml), 3-methyladenine (3-MA, 10 mM) ammonium chloride (NH₄Cl, 20 mM) were from sigma.