FIGURE 5:

The CLN1 transcription factor Tec1 antagonizes Far1-independent G1 arrest. (A) Empty vector or TEC1 plasmids (pPP681, pPP4042, pPP4043) were introduced into the indicated strains (PPY1716, PPY1789, PPY1867, YPAP157, YPAP161). Cells were spread on selective media (SC –Ura), overlaid with filter disks containing 20 μl of α factor (20 or 100 μM), and then incubated at 30°C for 2 d. (B) Empty vector or TEC1 plasmids (pPP680, pPP4050, pPP4051) were introduced into the indicated P_GAL1-CDC20 strains (PPY2014, PPY2063, YPAP165, YPAP167, YPAP171). Cells were released from the mitotic block into medium containing α factor, and the percentage of cells that escaped G1 arrest was measured by scoring budding after 120 min. Bars, mean ± range; the two strains at right (n = 3) were assayed together in a set of experiments separate from the four strains at left (n = 2–5). In each strain, differences between vector and TEC1 (wild type and T273M) sets were ranked significant by a two-tailed unpaired t test (from left to right, p = 0.008, 0.009, 0.014, 0.002, 0.005, 0.0002). (C) P_GAL1-CDC20 strains (PPY2014, YPAP171) contained empty vector or a TEC1-T273M plasmid (pPP680, pPP4051). Cells were released from the mitotic block into medium containing α factor, and DNA content was monitored at the indicated times. Graphs show mean ± range of two separate experiments (some error bars are smaller than symbols).