Skip to main content
. 2000 Nov;11(11):3993–4003. doi: 10.1091/mbc.11.11.3993

Figure 3.

Figure 3

Figure 3

Overexpression of Int6 specifically induces Pap1-dependent drug resistance and sensitivity to UV or oxidative stress. (A) Transformants of S. pombe h- leu1–32 (pap1+; upper panels) or h- pap1::ura4+ ura4-D18 leu1–32 (pap1Δ; lower panels) containing either pREP3X (vector) or the pREP3X cDNA library plasmid directing expression of int6 (int6) were streaked onto minimal agar plates with or without caffeine at the concentrations indicated. Plates were photographed after five days incubation at 30°C. (B) Int6-induced multi-drug resistance. Transformants of S. pombe h- leu1–32 containing pREP3X (vector), or pREP3X cDNA library plasmids directing expression of pap1 (pap1) or int6 (int6) were streaked onto minimal agar plates containing no drug (ND), 20 μg/ml cycloheximide (CHX), 8 μg/ml actinomycin D (ACD), 15 μg/ml MBC or 3 μg/ml staurosporine (STS). Plates were photographed after 4–7 days incubation at 30°C. (C) The sensitivities to UV radiation or hydrogen peroxide exposure of transformants of S. pombe h- leu1–32 containing either pREP3X (vector) or pREP3X-int6 (int6) were determined as described in MATERIALS AND METHODS. Percentages of surviving cells were determined in triplicate. Error bars represent one SD; for several data points these are smaller than the plot symbols. (D) Overexpression of eIF3 subunits other than Int6 does not confer drug resistance. Expression of p116-FLAG and HA-p47 was confirmed by Western blotting with anti-FLAG and anti-HA antibodies (left hand panels). Strains lacking the tagged proteins (-) served as negative controls. Strains transformed with pREP3X (vector) or expressing HA-int6, HA-p47, or p116-FLAG, as indicated, were streaked onto minimal agar plates containing no drug (ND) or 15 μg/ml MBC. Plates were photographed after 5 days incubation at 30°C.