A, UBIAD1 is localized on the Golgi apparatus of HEK293 cells. HEK293 cells were transfected with plasmid UBIAD1-EGFP and plasmid Golgi-RFP (Golgi marker). The nuclei were stained with DAPI. a, UBIAD1-EGFP expressed in HEK293 cells; b, nuclei stained with DAPI; c, the merge of a and b; d, Golgi marker expressed in HEK293 cells; e, the merge of b and d; f, the merge of a, b and d. Arrows point to the UBIAD1-EGFP. B, UBIAD1 is localized on the Golgi of a single HEK293 cell; a, UBIAD1-EGFP expressed in HEK293 cell; Arrows point to the UBIAD1-EGFP. b and e, Ds Red-Golgi marker; Arrows point to the Golgi. c, the merge of a and b; The nuclei in a, b and c were stained with DAPI. d, The endogenous UBIAD1 was measured. HEK293 cell stained with UBIAD1 antibody and the FITC-conjugated secondary antibody; Arrow point to the endogenous UBIAD1. f, the merge of d and e. C, UBIAD1 is localized on the ER of a single HEK293 cell; a, UBIAD1-EGFP expressed in a single HEK293 cell; b and e, Ds Red-ER marker; c, the merge of a and b; The nuclei in a, b and c were stained with DAPI. d, The endogenous UBIAD1 was measured. HEK293 cell stained with UBIAD1 antibody and the FITC-conjugated secondary antibody; f, the merge of d and e. The arrangement of arrows is similar to those in figure 2B. D, UBIAD1 is not detected on the plasma membrane. a, UBIAD1-EGFP expressed in a single HEK293 cell; b, RFP-H-Ras (marker for plasma membrane and the Golgi); Arrow points to plasma membrane. c, the merge of a and b; d, The endogenous UBIAD1 was measured. HEK293 cell stained with UBIAD1 antibody and the R-PE-conjugated secondary antibody; e, Orail1-EGFP (marker for plasma membrane); Arrow points to plasma membrane. f, the merge of d and e. E, As in HEK293 cells, UBIAD1 is expressed on the ER and the Golgi, but not on the plasma membrane, in bladder carcinoma T24 cells. a, d and g, UBIAD1-EGFP expressed in T24 cells; Arrows point to UBIAD1-EGFP. b, e and h, markers for the Golgi (b, Ds Red-Golgi), ER (e, Ds Red-ER) and plasma membrane (h, BFP-H-Ras), respectively; Arrows point to the Golgi, the ER and the plasma membrane. c, Merge of a and b; f, Merge of d and e; i, Merge of g and h. All experiments were repeated at least three times. Size bar represents 10 µm.