Overexpressed Tcb3-GFP Punctum Preferentially co-localizes with the Medial-Golgi-Resident Marker mRFP-Gos1
(A) tcb3Δ cells expressing Tcb3-GFP and mRFP-Sed5 (cis-Golgi marker) or mRFP-Gos1 (medial-Golgi marker) under TDH3 promoter or Sec7-mRFP (trans-Golgi marker) under ADH promoter were grown at 25°C and imaged by DIC and fluorescence microscopy. The images were taken at 24 z-sections with 0.2-μm parallel intervals. Scale bar, 5 μm. The percentage of cells showing co-localization of Tcb3-GFP and mRFP-Sed5 puncta, mRFP-Gos1 puncta, or Sec7-mRFP puncta was quantified, and the data represent means ± SD of three independent experiments, each based on more than 60 cells. ∗p < 0.05 by Student's t-test.
(B) tcb3Δ cells expressing Tcb3-GFP with mRFP-Gos1 under TDH3 promoter were observed with super-resolution confocal live imaging microscopy (SCLIM). Representative 3D images of whole cells are shown. Arrows in the images indicate nER-medial-Golgi contact sites, and arrowheads point to cER-medial-Golgi contact sites. Scale bar, 2 μm.