title: Phosphorylation of residues inside the SNARE complex suppresses secretory vesicle fusion.
abstract: Membrane fusion is essential for eukaryotic life, requiring SNARE proteins to zipper up in an α-helical bundle to pull two membranes together. Here, we show that vesicle fusion can be suppressed by phosphorylation of core conserved residues inside the SNARE domain. We took a proteomics approach using a PKCB knockout mast cell model and found that the key mast cell secretory protein VAMP8 becomes phosphorylated by PKC at multiple residues in the SNARE domain. Our data suggest that VAMP8 phosphorylation reduces vesicle fusion in vitro and suppresses secretion in living cells, allowing vesicles to dock but preventing fusion with the plasma membrane. Markedly, we show that the phosphorylation motif is absent in all eukaryotic neuronal VAMPs, but present in all other VAMPs. Thus, phosphorylation of SNARE domains is a general mechanism to restrict how much cells secrete, opening the door for new therapeutic strategies for suppression of secretion.
authors.affiliation: Department of Chemical and Systems Biology, Stanford University, Stanford, CA, USA sethma@stanford.edu tobias1@stanford.edu.
authors.forename: Seth
authors.identifier: 0000-0002-1519-8916
authors.initials: S
authors.lastname: Malmersjö
authors.affiliation: Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland Functional Genomics Center Zurich, ETH Zurich/University of Zurich, Zurich, Switzerland.
authors.forename: Serena
authors.initials: S
authors.lastname: Di Palma
authors.affiliation: Departments of Molecular and Cellular Physiology, Neurology and Neurological Sciences, Photon Science, and Structural Biology, Stanford University, Stanford, CA, USA Howard Hughes Medical Institute, Stanford, CA, USA.
authors.forename: Jiajie
authors.identifier: 0000-0003-4288-3203
authors.initials: J
authors.lastname: Diao
authors.affiliation: Departments of Molecular and Cellular Physiology, Neurology and Neurological Sciences, Photon Science, and Structural Biology, Stanford University, Stanford, CA, USA Howard Hughes Medical Institute, Stanford, CA, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Lai
authors.affiliation: Departments of Molecular and Cellular Physiology, Neurology and Neurological Sciences, Photon Science, and Structural Biology, Stanford University, Stanford, CA, USA Howard Hughes Medical Institute, Stanford, CA, USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Pfuetzner
authors.affiliation: Departments of Molecular and Cellular Physiology, Neurology and Neurological Sciences, Photon Science, and Structural Biology, Stanford University, Stanford, CA, USA Howard Hughes Medical Institute, Stanford, CA, USA.
authors.forename: Austin L
authors.initials: AL
authors.lastname: Wang
authors.affiliation: Department of Pediatrics, Stanford University, Stanford, CA, USA.
authors.forename: Moira A
authors.initials: MA
authors.lastname: McMahon
authors.affiliation: Department of Chemical and Systems Biology, Stanford University, Stanford, CA, USA.
authors.forename: Arnold
authors.initials: A
authors.lastname: Hayer
authors.affiliation: Department of Pediatrics, Stanford University, Stanford, CA, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Porteus
authors.affiliation: Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland.
authors.forename: Bernd
authors.initials: B
authors.lastname: Bodenmiller
authors.affiliation: Departments of Molecular and Cellular Physiology, Neurology and Neurological Sciences, Photon Science, and Structural Biology, Stanford University, Stanford, CA, USA Howard Hughes Medical Institute, Stanford, CA, USA.
authors.forename: Axel T
authors.initials: AT
authors.lastname: Brunger
authors.affiliation: Department of Chemical and Systems Biology, Stanford University, Stanford, CA, USA sethma@stanford.edu tobias1@stanford.edu.
authors.forename: Tobias
authors.identifier: 0000-0003-4339-3804
authors.initials: T
authors.lastname: Meyer
mesh_terms: D000818:Animals; D002460:Cell Line; D008407:Mast Cells / Q000502:physiology; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D040901:Proteomics; D050683:R-SNARE Proteins / Q000378:metabolism*; D051381:Rats; D022142:Secretory Vesicles / Q000378:metabolism*
chemical_list: D050683:R-SNARE Proteins; C491830:Vamp8 protein, rat; D011493:Protein Kinase C
keywords: SNARE complex; VAMP8; mast cell degranulation; protein kinase C; secretion