Files S1 - S6 contain underlying data for figures published in the paper. S1: sgRNA counts of unsorted and sorted population from the CRISPR screen detailed in the paper, which aimed to identify genes that regulate glycoprotein secretion. Sheet 1 is a table of sgRNA counts, including the gene name that each sgRNA targets. Sheet 2 includes full descriptions of the populations. S2: MaGECK (version 0.5.7) analysis of sgRNA counts from the CRISPR screen. Both MaGECK-MLE and MaGECK-RRA results are shown. False discovery rates (FDR) from this table were used to create figure 1C-E S3: Raw FCS files from flow cytometry staining of sorted samples, used to create figure 1B. S4: Raw chemiluminescence data, used to create figure 2. S5: Unedited image files used in Figures 3D, 4 and 5. S6: Data output from Cell Profiler, showing total number of cells identified per image and number of cells classified as having fragmented or intact Golgi.

E1-E4 is extended data for figures and tables published in the paper. E1: Figure of all genes analysed for having fragmented Golgi; top hits from this talbe are shown in Figure 3C. Percentage of cells with fragmented Golgi for all of the hits screened in the tertiary screen. As in Figure 3C, hits are arranged alphabetically and coloured by cell count, with darker blue spots representing more confluent wells. E2: Sequence of P5 primers used for PCR amplification of sgRNA. E3: Sequence of P7 primers used for PCR amplification of sgRNA. E4: Details of the siGenome pooled siRNA library used in secondary screening.