Transcription levels of ER stress response
proteins in SHR3 and shr3Δ6 strains.
(A) Total RNA preparations (5 μg) isolated from cultures of FGY58
(SHR3) and FGY60 (shr3Δ6) transformed
with pPL257 (GAP1) were separated by gel
electrophoresis, transferred to nylon filters, and hybridized with
radiolabeled DNA probes specific for KAR2,
PDI1, EUG1, and ACT1.
Cultures were grown at 30°C for 2.5 h in SUD in the absence or
presence of 4 μg/ml tunicamycin (Tuni) or 3 mM DTT. Phosphorimager
quantitations from two independent experiments are presented as ratios
of basal transcription levels with respect to the SHR3
strain (FGY58) normalized to 1; error bars represent 1 standard
deviation. (B) The stress response pathway is induced in strains
expressing mutant alleles of gap1. Cultures of strains
FGY58 (SHR3) transformed with plasmid pPL257
(GAP1, black bar, lane 1) and FGY60
(shr3Δ6) transformed with plasmids pPL257
(GAP1, hatched bar, lane 2), pFG80
(gap1–119), pFG81 (gap1–159), pFG82
(gap1–171), pFG83 (gap1–411), and pFG84
(gap1–417) (white bars, lanes 3–7, respectively) were
grown at 30°C for 4 h in SPD (plus adenine and lysine). RNA was
isolated and analyzed using radiolabeled DNA probes specific for
KAR2 and ACT1. Phosphorimager
quantitations from three independent experiments are presented as
ratios of the transcription levels with respect to the
SHR3 strain (FGY58, lane 1) normalized to 1; error bars
represent 1 standard deviation.