SODIUM-SALICYLATE AND YEAST HEAT-SHOCK GENE-TRANSCRIPTION

The anti-inflammatory drug sodium salicylate modulates the activity of specific transcription factors in humans. Here we show that salicylat e and sorbate, another organic acid, stimulate DNA binding by yeast he at shock transcription factor (HSF) in vivo. Surprisingly, salicylate inhibits heat shock gene transcription even in cells induced by a prio r heat shock. This inhibition of transcription occurs at a step after HSF and transcription factor IID binding but before promoter melting b y RNA polymerase. Salicylate appears to generate a tight binding but a ctivation-impotent HSF by cytoplasmic acidification, since inhibiting proton efflux from cells triggers this same DNA binding and inhibition of heat shock gene expression.