Multiple golgins are required to support extracellular matrix secretion, modification, and assembly.

The secretion of extracellular matrix (ECM) proteins is vital to the maintenance of tissue health. One major control point of this process is the Golgi apparatus, whose dysfunction causes numerous connective tissue disorders. We therefore sought to investigate the role of two Golgi organizing proteins, GMAP210 and Golgin-160, in ECM secretion. CRISPR knockout of either protein had distinct impacts on Golgi organization, with Golgin-160 knockout causing Golgi fragmentation and vesicle accumulation, and GMAP210 loss leading to cisternal fragmentation, dilation, and the accumulation of tubulovesicular structures. Both golgins were required for fibrillar collagen organization and glycosaminoglycan synthesis suggesting nonredundant functions in these processes. Furthermore, proteomics analysis revealed both shared and golgin-specific changes in the secretion of ECM proteins. We therefore propose that golgins are collectively required to create the correct physical-chemical space to support efficient ECM protein secretion, modification, and assembly. This is the first time that Golgin-160 has been shown to be required for ECM secretion.