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. 1984 Mar 1;98(3):1063–1071. doi: 10.1083/jcb.98.3.1063

Separation of the osmotically driven fusion event from vesicle-planar membrane attachment in a model system for exocytosis

PMCID: PMC2113141  PMID: 6699082

Abstract

We demonstrate that there are two experimentally distinguishable steps in the fusion of phospholipid vesicles with planar bilayer membranes. In the first step, the vesicles form a stable, tightly bound pre-fusion state with the planar membrane; divalent cations (Ca++) are required for the formation of this state if the vesicular and/or planar membrane contain negatively charged lipids. In the second step, the actual fusion of vesicular and planar membranes occurs. The driving force for this step is the osmotic swelling of vesicles attached (in the pre- fusion state) to the planar membrane. We suggest that osmotic swelling of vesicles may also be crucial for biological fusion and exocytosis.

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Selected References

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  1. Adams P. R., Constanti A., Brown D. A., Clark R. B. Intracellular Ca2+ activates a fast voltage-sensitive K+ current in vertebrate sympathetic neurones. Nature. 1982 Apr 22;296(5859):746–749. doi: 10.1038/296746a0. [DOI] [PubMed] [Google Scholar]
  2. Brown E. M., Pazoles C. J., Creutz C. E., Aurbach G. D., Pollard H. B. Role of anions in parathyroid hormone release from dispersed bovine parathyroid cells. Proc Natl Acad Sci U S A. 1978 Feb;75(2):876–880. doi: 10.1073/pnas.75.2.876. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Caulfield J. P., Lewis R. A., Hein A., Austen K. F. Secretion in dissociated human pulmonary mast cells. Evidence for solubilization of granule contents before discharge. J Cell Biol. 1980 May;85(2):299–312. doi: 10.1083/jcb.85.2.299. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Chandler D. E., Heuser J. E. Arrest of membrane fusion events in mast cells by quick-freezing. J Cell Biol. 1980 Aug;86(2):666–674. doi: 10.1083/jcb.86.2.666. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Chandler D. E., Heuser J. Membrane fusion during secretion: cortical granule exocytosis in sex urchin eggs as studied by quick-freezing and freeze-fracture. J Cell Biol. 1979 Oct;83(1):91–108. doi: 10.1083/jcb.83.1.91. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Cohen F. S., Akabas M. H., Finkelstein A. Osmotic swelling of phospholipid vesicles causes them to fuse with a planar phospholipid bilayer membrane. Science. 1982 Jul 30;217(4558):458–460. doi: 10.1126/science.6283637. [DOI] [PubMed] [Google Scholar]
  7. Cohen F. S., Zimmerberg J., Finkelstein A. Fusion of phospholipid vesicles with planar phospholipid bilayer membranes. II. Incorporation of a vesicular membrane marker into the planar membrane. J Gen Physiol. 1980 Mar;75(3):251–270. doi: 10.1085/jgp.75.3.251. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Colquhoun D., Neher E., Reuter H., Stevens C. F. Inward current channels activated by intracellular Ca in cultured cardiac cells. Nature. 1981 Dec 24;294(5843):752–754. doi: 10.1038/294752a0. [DOI] [PubMed] [Google Scholar]
  9. Düzgünes N., Nir S., Wilschut J., Bentz J., Newton C., Portis A., Papahadjopoulos D. Calcium- and magnesium-induced fusion of mixed phosphatidylserine/phosphatidylcholine vesicles: effect of ion binding. J Membr Biol. 1981 Apr 15;59(2):115–125. doi: 10.1007/BF01875709. [DOI] [PubMed] [Google Scholar]
  10. Kachadorian W. A., Muller J., Finkelstein A. Role of osmotic forces in exocytosis: studies of ADH-induced fusion in toad urinary bladder. J Cell Biol. 1981 Nov;91(2 Pt 1):584–588. doi: 10.1083/jcb.91.2.584. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Kalderon N., Gilula N. B. Membrane events involved in myoblast fusion. J Cell Biol. 1979 May;81(2):411–425. doi: 10.1083/jcb.81.2.411. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Kwok R., Evans E. Thermoelasticity of large lecithin bilayer vesicles. Biophys J. 1981 Sep;35(3):637–652. doi: 10.1016/S0006-3495(81)84817-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Lagunoff D. Membrane fusion during mast cell secretion. J Cell Biol. 1973 Apr;57(1):252–259. doi: 10.1083/jcb.57.1.252. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Lawson D., Raff M. C., Gomperts B., Fewtrell C., Gilula N. B. Molecular events during membrane fusion. A study of exocytosis in rat peritoneal mast cells. J Cell Biol. 1977 Feb;72(2):242–259. doi: 10.1083/jcb.72.2.242. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. LeNeveu D. M., Rand R. P., Parsegian V. A. Measurement of forces between lecithin bilayers. Nature. 1976 Feb 19;259(5544):601–603. doi: 10.1038/259601a0. [DOI] [PubMed] [Google Scholar]
  16. Lux H. D., Neher E., Marty A. Single channel activity associated with the calcium dependent outward current in Helix pomatia. Pflugers Arch. 1981 Mar;389(3):293–295. doi: 10.1007/BF00584792. [DOI] [PubMed] [Google Scholar]
  17. Nikaido H., Rosenberg E. Y. Effect on solute size on diffusion rates through the transmembrane pores of the outer membrane of Escherichia coli. J Gen Physiol. 1981 Feb;77(2):121–135. doi: 10.1085/jgp.77.2.121. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Olson F., Hunt C. A., Szoka F. C., Vail W. J., Papahadjopoulos D. Preparation of liposomes of defined size distribution by extrusion through polycarbonate membranes. Biochim Biophys Acta. 1979 Oct 19;557(1):9–23. doi: 10.1016/0005-2736(79)90085-3. [DOI] [PubMed] [Google Scholar]
  19. Ornberg R. L., Reese T. S. Beginning of exocytosis captured by rapid-freezing of Limulus amebocytes. J Cell Biol. 1981 Jul;90(1):40–54. doi: 10.1083/jcb.90.1.40. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Palade G. E., Bruns R. R. Structural modulations of plasmalemmal vesicles. J Cell Biol. 1968 Jun;37(3):633–649. doi: 10.1083/jcb.37.3.633. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Pallotta B. S., Magleby K. L., Barrett J. N. Single channel recordings of Ca2+-activated K+ currents in rat muscle cell culture. Nature. 1981 Oct 8;293(5832):471–474. doi: 10.1038/293471a0. [DOI] [PubMed] [Google Scholar]
  22. Parsegian V. A., Fuller N., Rand R. P. Measured work of deformation and repulsion of lecithin bilayers. Proc Natl Acad Sci U S A. 1979 Jun;76(6):2750–2754. doi: 10.1073/pnas.76.6.2750. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Pazoles C. J., Pollard H. B. Evidence for stimulation of anion transport in ATP-evoked transmitter release from isolated secretory vesicles. J Biol Chem. 1978 Jun 10;253(11):3962–3969. [PubMed] [Google Scholar]
  24. Pollard H. B., Tack-Goldman K., Pazoles C. J., Creutz C. E., Shulman N. R. Evidence for control of serotonin secretion from human platelets by hydroxyl ion transport and osmotic lysis. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5295–5299. doi: 10.1073/pnas.74.12.5295. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Portis A., Newton C., Pangborn W., Papahadjopoulos D. Studies on the mechanism of membrane fusion: evidence for an intermembrane Ca2+-phospholipid complex, synergism with Mg2+, and inhibition by spectrin. Biochemistry. 1979 Mar 6;18(5):780–790. doi: 10.1021/bi00572a007. [DOI] [PubMed] [Google Scholar]
  26. Rand R. P. Interacting phospholipid bilayers: measured forces and induced structural changes. Annu Rev Biophys Bioeng. 1981;10:277–314. doi: 10.1146/annurev.bb.10.060181.001425. [DOI] [PubMed] [Google Scholar]
  27. Satir B., Schooley C., Satir P. Membrane fusion in a model system. Mucocyst secretion in Tetrahymena. J Cell Biol. 1973 Jan;56(1):153–176. doi: 10.1083/jcb.56.1.153. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Tandler B., Poulsen J. H. Fusion of the envelope of mucous droplets with the luminal plasma membrane in acinar cells of the cat submandibular gland. J Cell Biol. 1976 Mar;68(3):775–781. doi: 10.1083/jcb.68.3.775. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Wilkinson D. A., Nagle J. F. Dilatometry and calorimetry of saturated phosphatidylethanolamine dispersions. Biochemistry. 1981 Jan 6;20(1):187–192. doi: 10.1021/bi00504a031. [DOI] [PubMed] [Google Scholar]
  30. Yellen G. Single Ca2+-activated nonselective cation channels in neuroblastoma. Nature. 1982 Mar 25;296(5855):357–359. doi: 10.1038/296357a0. [DOI] [PubMed] [Google Scholar]

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