Fig. 2. Panx1 and Panx3 are localized to the cell surface when expressed in NRK cells. Confocal microscopic images of NRK cells expressing untagged Panx1 or Panx3 (A) or GFP-tagged Panx1 or Panx3 (B). Immunolabeling with mouse (anti-Panx1) and human (anti-hPANX1) antibodies revealed that Panx1 and Panx1-GFP were found at the cell surface with increased intensity at cell-cell interfaces when both cells expressed Panx1 or Panx1-GFP. Similar to that observed for Panx1, Panx3 displayed cell surface localization. However, Panx3-GFP was retained within the cell and colocalized with protein disulfide isomerase, an endoplasmic reticulum protein. Bars, 10 µm.