Figure 5.

The effects of HDA1 and RPD3 disruptions on gene activity. Determination of noninduced and activated transcription in wild-type, hda1, and rpd3 cells was performed through β-galactosidase assays. YDS3 (wild-type) (□), SRY3D2 (hda1) (•), or SRYR3 (rpd3) (▴) was transformed with either (A) pMH313 (containing a 2.4-kb DraI fragment of the PHO5 promoter fused to lacZ) (39) or (B) pCLUC (containing the entire CUP1 promoter fused to lacZ) (40), and induced for various time periods (38) before harvesting and determining β-galactosidase activity in cell extracts by the following formula: units = OD₄₂₀ × 10³ mg⁻¹·min⁻¹. The values given represent an average of the data obtained from at least five independent transformants. The standard deviations for these data were <30% and <10%, respectively, for the PHO5 and CUP1 promoters.