Cellular localization and trafficking of PIN1-RFP. (A) Colocalization of PIN1 proteins (in red) with the ER marker HDEL-GFP (in green) 10 h after transformation. (B) PIN1-RFP preferentially localizes to the plasma membrane (PM) after 16 h. (C) 24 h after transformation, PIN1-RFP shows vacuolar localization indicating lytic turnover. (D) Relative number of cells showing pronounced PIN1-RFP signal in the ER, PM, and in the vacuole over a time course of 24 h after transformation. Cells showing PIN1-RFP both at PM and either at the ER or vacuole were ascertained as ER or vacuole positive, respectively. Bars = 10 μm.