Dev Cell. 2019 Jun 3;49(5):786-801.e6.

Mafalda Lopes-da-Silva¹, Jessica J McCormack², Jemima J Burden³, Kimberly J Harrison-Lavoie², Francesco Ferraro², Daniel F Cutler⁴

1. Endothelial Cell Biology Laboratory, MRC Laboratory for Molecular Cell Biology, University College London, London, UK. Electronic address: mafalda.silva@ucl.ac.uk.
2. Endothelial Cell Biology Laboratory, MRC Laboratory for Molecular Cell Biology, University College London, London, UK.
3. Electron Microscopy Laboratory, MRC Laboratory for Molecular Cell Biology, University College London, London, UK.
4. Endothelial Cell Biology Laboratory, MRC Laboratory for Molecular Cell Biology, University College London, London, UK. Electronic address: d.cutler@ucl.ac.uk.

Abstract

How can anterograde membrane trafficking be modulated by physiological cues? A screen of Golgi-associated proteins revealed that the ARF-GEF GBF1 can selectively modulate the ER-Golgi trafficking of prohaemostatic von Willebrand factor (VWF) and extracellular matrix (ECM) proteins in human endothelial cells and in mouse fibroblasts. The relationship between levels of GBF1 and the trafficking of VWF into forming secretory granules confirmed GBF1 is a limiting factor in this process. Further, GBF1 activation by AMPK couples its control of anterograde trafficking to physiological cues; levels of glucose control GBF1 activation in turn modulating VWF trafficking into secretory granules. GBF1 modulates both ER and TGN exit, the latter dramatically affecting the size of the VWF storage organelles, thereby influencing the hemostatic capacity of the endothelium. The role of AMPK as a central integrating element of cellular pathways with intra- and extra-cellular cues can now be extended to modulation of the anterograde secretory pathway.

Presented by Mafalda Lopes-da-Silva