(A) In scd2Δ cells, OptoQ61L induces CRIB and Pak1 recruitment but fails to recruit its GEF Scd1. Data layout as in Fig 3C. N = 3; n > 20 cells per experiment; pCRIB-3GFP = 1.4e-18; pPak1-sfGFP = 8.4e-15; pScd1-3GFP = 0.2. (B) Scd1-3GFP signal at cell tips over time in OptoQ61L and Opto scd2+ (p = 1.6e-09), scd2Δ (p = 0.5), scd2275-536 (p = 0.1), and scd2K463A cells (p = 0.8). N = 3; n > 15 cells. (C) Mixtures of scd2Δ OptoQ61L (purple) and scd2Δ control cell expressing Cdc42-sfGFPSW. Data presented as in Fig 3H. Note that there is little change in Cdc42-sfGFPSW distribution in scd2Δ OptoQ61L cells. (D) OptoQ61L fails to induce cell-side accumulation of endogenous Cdc42-sfGFPSW in scd2Δ cells. N = 3; n > 20 cells per experiment; p = 0.32. Bars = 2 μm. All underlying numerical values are available in S4 Data. A.U., arbitrary units; max proj., maximum projection.