Immunofluorescence was carried out as described previously (Lavieu et al., 2014 (link)). Anti-Gpp130 and anti-Golgin97 antibodies were purchased from Covance and Abcam, respectively. Anti-rabbit Atto594 (Rockland), anti-mouse Atto594 (Sigma-Aldrich), and anti-mouse- and anti-rabbit 635P (Abberior) secondary antibodies were used for the STED experiments.