Figure 5.

(a) Induction of anti-Ste4 reactive protein on incubation in galactose. Cells were grown in selective glucose medium and transferred at time 0 h to galactose medium. Aliquots were removed at the indicated times and lysates prepared. Then, 20 μg total protein were loaded per lane. Nonspecific bands are as in Fig. 4a. Strain backgrounds: βwt (wild-type) or SK1007 (ste4 gpa1). Plasmids: pGT5 (vector), pSTE4-GPA1-b (STE4-GPA1-b), pG1501 (GPA1), pGT-STE4–2 (STE4). (b) The amounts of anti-Ste4 reactive protein were quantitated by using the National Institutes of Health image program. Panels were scanned from the same exposure. (c) Induction of mating ability on incubation in galactose. A total of 4 × 10⁷ exponentially growing washed cells were incubated at 30°C for the times indicated with a large excess of washed tester NKY102 (MATα ade8) cells. After washing, appropriate dilutions were plated on selective plates to score diploids, tester, and plasmid-carrying strain. Mating efficiencies represent the number of diploid cells per SK1007(pSTE4-GPA1-b) or SK1007 (pG1501 + pGT-STE4–2) cell.