FIG. 4.

Effect of temperature shift on TFIID integrity in WT and TAF1 region 4 mutant strains. WT and ts mutant cells (as indicated, top) were grown to log phase at 30°C and shifted to 37°C. Cells were collected at 0, 15, 30, 45, and 60 min after the temperature shift (top), WCEs were prepared and normalized to total protein content, and equal amounts of total protein were used for co-IP assays with anti-HA antibody (MAb 12CA5) (A) or anti-Taf4p antibodies (B). Immunoprecipitates were fractionated by SDS-PAGE and blotted, and specific antibodies (left) were used to probe the blots as detailed for Fig. 1 and 2. The same precleared lysate was used for all IPs. Input lanes represent 1.5% of the total precleared lysate; pellet lanes contain approximately 15% of the immunoprecipitate. (C) Summary of the results of the two sets of co-IP experiments; dashed lines denote reduced amounts of association as scored by co-IP.