Fig. 2. Egfr^tsla is rapidly made inactive by a shift to 30°C. (A) Diagram of the protocol, see text. (B) Blot probed for Egfr. The DNA used and the time incubated at 30°C are indicated. (C) Blot probed for pMAPK shows pathway activation (same gel as is shown in B). Note, pMAPK levels appear constant over 60 minutes at 30°C for wild-type Egfr. However, for Egfr^tsla, although pMAPK is detected at 18°C, after the shift to 30°C, the level falls rapidly down to background levels. Asterisks in B and C indicate examples of the 60-minute time-point bands used in the quantification shown in Fig. 3. (D) Same blot as in C, re-probed for total MAPK (loading control).