Differential modulation of yeast actin, tubulin, and YPT1 mRNA levels by cycloheximide.

We have examined the effects of cycloheximide (Chx) on transcription of genes encoding the yeast beta-actin (ACT), beta-tubulin (TUB) and yeast protein 1 (YPT1). As in mammalian cells, Chx caused an increase in levels of ACT, but not TUB, transcripts. The YPT1 gene was also activated. Induction of Chx was further studied by placing the promoter regions of the ACT and YPT1 genes in front of a globin (GLB)-encoding reporter gene (GLB) on yeast plasmids. Induction of GLB mRNA synthesis by Chx was not seen with either promoter; the YPT1 promoter was, however, strongly inducible by Chx if glucose was present. The YPT1 coding sequence conferred Chx inducibility on both the YPT1 and ACT promoters, suggesting that it may contain a transcription regulatory element.