AB: HeLa cells were transfected for 24h with calnexin-WT-HA, calnexin-CA-HA, or calnexin-AC-HA. Cells were incubated with 3H-palmitic acid for 2h, washed and further incubated for different times at 37°C in complete medium prior to immunoprecipitation using anti-calnexin or anti-HA antibodies. Immunoprecipitates were split into two, run on SDS-PAGE and analyzed either by autoradiography (3H-palmitate) or Western blotting (anti-HA). Autoradiograms were quantified using the Typhoon Imager (Image QuantTool, GE healthcare). Errors correspond to standard deviations (n = 3). CD: HeLa cells were incubated with 3H-palmitic acid for different times at 37°C, washed prior to immunoprecipitation using anti-calnexin antibodies. Immunoprecipitates were split into two, run on SDS-PAGE and analyzed either by autoradiography (3H-palmitate) or Western blotting (anti-calnexin). Errors correspond to standard deviations (n = 4). E: Validation of the model output though comparison of the in silico experiments with experimental data that was not used in the calibration of the model. Solid line is the mean of the simulations of 382 models; the shaded area is defined by the first and the third quartile of the simulations of 382 models (details of the in silico labelling experiment can be found in the Supplemental Information).