Figure 5

GA structure in non-polarized MDCK cells transfected with (A) UPIb; (B) UPIb-EGFP, (C) UPIb/UPIIIa, (D) UPIb/UPIIIa-EGFP, or (E) GPI–GFP. Cells transfected with UPIb were immunolabelled with antibodies against UPIb and cells transfected with UPIb/UPIIIa were immunolabelled with antibodies against UPIIIa. (A,B) Anti-giantin immunolabeling shows that transport of untagged or EGFP-tagged UPIb causes fragmentation of the GA. Note untagged and tagged UPIb on the PM of MDCK cells. (C,D) The transport of assembled heterodimers UPIb/UPIIIa or UPIb/UPIIIa-EGFP also causes fragmentation of the GA. Untagged and tagged UPIb/UPIIIa heterodimers are seen on the PM of MDCK cells. (E) The GA structure is not changed in GPI-GFP-expressing MDCK cells. Bars: 10 µm (A–E).