Fig. 4. The conserved WH2/V domain of Vrp1p is not essential for viability at 37°C or cortical actin patch polarization. (A) Viability at 24 and 37°C of vrp1Δ (AMY88) carrying YCplac111 vector (Vect), pAM228 (Vrp1p), pAM229 (Vrp1p_KA), pAM230 (Vrp1p_KE) or pAM231 (Vrp1p_69–817). Each strain was streaked for single colonies on YPUAD solid medium, incubated at either 24 or 37°C and photographed after 3 days. (B) Cortical actin patch polarization in vrp1Δ (AMY88) carrying YCplac111 vector (Vect), pAM228 (Vrp1p), pAM229 (Vrp1p_KA), pAM230 (Vrp1p_KE) or pAM231 (Vrp1p_69–817). Cells were grown in YPUAD to exponential phase at 24°C and either left at 24°C or shifted to 37°C for 2 h. The cells were fixed, permeabilized and F-actin stained with Alexa-488-conjugated phalloidin. Stained cells were viewed by fluorescence microscopy. Fields containing small-budded cells are shown to compare the polarization of cortical actin patches. All panels are at equal magnification.