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Erik Renström

Erik Renström

Vice-chancellor

Erik Renström

Delay between fusion pore opening and peptide release from large dense-core vesicles in neuroendocrine cells.

Author

  • Sebastian Barg
  • Charlotta Olofsson
  • Jenny Schriever-Abeln
  • Anna Wendt
  • Samuel Gebre-Medhin
  • Erik Renström
  • Patrik Rorsman

Summary, in English

Peptidergic neurotransmission is slow compared to that mediated by classical neurotransmitters. We have studied exocytotic membrane fusion and cargo release by simultaneous capacitance measurements and confocal imaging of single secretory vesicles in neuroendocrine cells. Depletion of the readily releasable pool (RRP) correlated with exocytosis of 10%-20% of the docked vesicles. Some remaining vesicles became releasable after recovery of RRP. Expansion of the fusion pore, seen as an increase in luminal pH, occurred after approximately 0.3 s, and peptide release was delayed by another 1-10 s. We conclude that (1) RRP refilling involves chemical modification of vesicles already in place, (2) the release of large neuropeptides via the fusion pore is negligible and only proceeds after complete fusion, and (3) sluggish peptidergic transmission reflects the time course of vesicle emptying.

Department/s

  • Islet cell physiology
  • Faculty of Medicine
  • Diabetes - Islet Cell Exocytosis
  • Division of Clinical Genetics
  • Department of Clinical Sciences, Malmö

Publishing year

2002

Language

English

Pages

287-299

Publication/Series

Neuron

Volume

33

Issue

2

Document type

Journal article

Publisher

Cell Press

Topic

  • Neurosciences

Keywords

  • Peptides/*metabolism
  • PC12 Cells
  • Neurosecretory Systems/cytology/*metabolism
  • Membrane Fusion/*physiology
  • Luminescent Proteins
  • Kinetics
  • Indicators and Reagents
  • Hydrogen-Ion Concentration
  • Exocytosis/*physiology
  • Fluorescence
  • Rats
  • Secretory Vesicles/*metabolism
  • Support
  • Non-U.S. Gov't
  • Electric Stimulation
  • Cell Line
  • Animal

Status

Published

Research group

  • Islet cell physiology
  • Diabetes - Islet Cell Exocytosis

ISBN/ISSN/Other

  • ISSN: 0896-6273