Experimental study demonstrates activation of HSF1, HSF2, and HSF3 by proteasome inhibitors in avian cells, suggesting the ubiquitin-proteasome pathway regulates all heat-shock factors.
Key Points
To elucidate the mechanisms by which proteasome inhibition triggers the activation of heat-shock transcription factors.
Treated avian cells with proteasome inhibitors and various alternative protease inhibitors.
Evaluated the activation and protein expression of HSF1, HSF2, and HSF3 in the presence or absence of the protein synthesis inhibitor cycloheximide.
Proteasome inhibitors specifically activated heat-shock-inducible factors HSF1 and HSF3, whereas other protease inhibitors did not.
Activation of HSFs by proteasome inhibition was completely blocked by cycloheximide-mediated inhibition of protein synthesis.
Development-associated HSF2 was unexpectedly activated alongside a marked increase in its protein accumulation.