Figure 4.

Arl1p partially colocalizes with GFP-Sft2p. (A) Endogenous Arl1p partially colocalizes with Sft2p. Myc-tagged Emp47p (cis-Golgi), or GFP-tagged Sec7p (late Golgi), or Sft2p (late Golgi) was used to identify the location of Arl1p by immunofluorescence microscopy, as described in Materials and Methods. Cells were fixed with formaldehyde; spheroplasts were prepared and reacted with purified anti-Arl1p, anti-GFP, or anti-myc antibodies, followed by appropriate secondary antibodies. Arrows indicate colocalization of Arl1p and Sft2p. Observations were replicated in three experiments. (B) Arl1-mRFP on centromeric vector, pRS315, under ADH promoter was transformed into arl1-deleted yeast containing Sec7-GFP or GFP-Sft2. Mid-log phase cells were imaged live with microscopy.