Figure 2. hTDP1 catalytic mutants induce hTOPO1-dependent toxicity.

A. top1Δ,tdp1Δ cells were co-transformed with vector control (ytop1Δ) or YCpGAL1-hTOP1·U (↑hTOPO1) and control vector (ytdp1Δ) or the indicated YCpGAL1-hTDP1·L plasmid. Exponentially growing cultures were diluted to an OD₅₉₅ of 0.3 and ten-fold serially diluted and spotted onto selective galactose plates. Plates were incubated at 30°C for 4 days. B. Total cell extracts from galactose induced top1Δ,tdp1Δ cells co-transformed with vector control (ytop1Δ) and the indicated YCpGAL1-hTDP1·L or its control vector (vector) used in (A) were resolved on 12% SDS-PAGE and stained with anti-human TDP1 and with anti-αTubulin. *: partly truncated hTDP1 proteins. Blot was cropped and exposure levels were not edited.