P4HB and infection: To determine whether the LC protein localizes to the endoplasmic reticulum (ER) or the Golgi apparatus during infection, its colocalization with PDI, an ER-resident luminal protein and marker of FCV replication complexes (RCs) (27), and GM130, a resident of the Golgi apparatus, was analyzed by confocal microscopy (Fig. 3B and C).