Turnover-defective GTP-bound Cdc42p (Cdc42p ^Q61L+TD ) affects fMAPK pathway-dependent polarity. (A) Confocal time-lapse analysis of Cdc3p-mCherry cells (PC7365) expressing GFP-Cdc42p^Q61L+TD (Q61L+TD, PC7654). Arrows refer to two buds growing simultaneously. Scale bar, 5 µm. (B) Fluorescence microscopy of Cdc3p-mCherry cells (PC7365) expressing GFP-Cdc42p (Cdc42, PC6454), GFP-Cdc42p^Q61L (Q61L, PC7458), or GFP-Cdc42p^Q61L+TD (Q61L+TD, PC7654). Cdc3p-mCherry (red) is a septin ring marker. Red arrows refer to multiple septin rings. Scale bar, 5 µm. (C) Microscopic examination of wild-type cells (PC986, S288c background) expressing GFP-Cdc42p (Cdc42, PC6454), GFP-Cdc42p^Q61L (Q61L, PC7458), or GFP-Cdc42p^Q61L+TD (Q61L+TD, PC7654). Scale bar, 5 µm. (D) Same strains as described in C were explored by microscopy.