Fig 2: Co-localization analysis between nsp2TF and organelle-specific cellular marker proteins in the secretory pathway.MARC-145 cells were infected with PRRSV SD95-21. At 10 hpi, cells were fixed, permeabilized and immunostained for nsp2TF (A), GP5 (B), M protein (C) and nsp2 (D). To label specific cellular compartments, the cells were co-stained with antibodies specific for ERGIC marker proteins ERGIC-53, COPA, COPB, or Golgin 97. Scale bars, 10 µm. (E) The level of co-localization between ERGIC makers and nsp2, nsp2TF, GP5 or M protein quantified by Pearson’s correlation coefficient using the Coloc2 module of the ImageJ software package. Mean (± SD) values from three replicates are shown. ***p < 0.001.

Fig 3: Detection of β-catenin–COPB protein interactions in SW480 total cell extracts following enrichment.(A) Pull-down with β-catenin-MBP construct, followed by immunoblot with COPB specific antibody. * indicates location of COPB protein. (B) Co-immunoprecipitation of COPB using anti-β-catenin antibody. Detection using anti-COPB antibody. * indicates location of COPB protein.

Fig 4: Co-localisation of COPB and Golgi-marker (TGN46) in SW480. Cells were stained with a-COPB (green) and a-TGN46 (red) antibody (scalebar = 5 µm). The zoom image underneath each box demonstrates that each arrow points to a spot of co-localisation, indicating that COPB can sometimes be found at the Golgi although it cannot be considered as a Golgi-marker.