Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents

This Article Full Text PDF (Full Text) PPT slides of all figures Alert me when this article is cited Citation Map Services Email this article Similar articles in this journal Similar articles in PubMed Alert me to new content in the JGP Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Sørensen, J. B. Articles by Neher, E. Search for Related Content PubMed PubMed Citation Articles by Sørensen, J. B. Articles by Neher, E. Social Bookmarking                      What's this?

¹ Max-Planck-Institute for Biophysical Chemistry, 37077 Göttingen, Germany
² The Center for Basic Neuroscience, Department of Molecular Genetics, and Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX 75390
³ Department of Medical Physiology and Biophysics, School of Medicine, University of Seville, 41009 Seville, Spain

Address correspondence to Jakob Balslev Sørensen, Max-Planck-Institut für Biophysikalische Chemie, Abteilung Membranbiophysik, Am Fassberg 11, D-37077 Göttingen, Germany. Fax: (49) 551-201-1688; email: jsoeren{at}gwdg.de

We tested the long-standing hypothesis that synaptotagmin 1 is the Ca²⁺ sensor for fast neurosecretion by analyzing the intracellular Ca²⁺ dependence of large dense-core vesicle exocytosis in a mouse strain carrying a mutated synaptotagmin C2A domain. The mutation (R233Q) causes a twofold increase in the K_D of Ca²⁺-dependent phospholipid binding to the double C2A-C2B domain of synaptotagmin. Using photolysis of caged calcium and capacitance measurements we found that secretion from mutant cells had lower secretory rates, longer secretory delays, and a higher intracellular Ca²⁺-threshold for secretion due to a twofold increase in the apparent K_D of the Ca²⁺ sensor for fast exocytosis. Single amperometric fusion events were unchanged. We conclude that Ca²⁺-dependent phospholipid binding to synaptotagmin 1 mirrors the intracellular Ca²⁺ dependence of exocytosis.

Key Words: chromaffin cell • membrane fusion • neurosecretion • capacitance measurement • amperometry

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				G. Nagy, I. Milosevic, R. Mohrmann, K. Wiederhold, A. M. Walter, and J. B. Sorensen The SNAP-25 Linker as an Adaptation Toward Fast Exocytosis Mol. Biol. Cell, September 1, 2008; 19(9): 3769 - 3781. [Abstract] [Full Text] [PDF]

				B. E. Paddock, A. R. Striegel, E. Hui, E. R. Chapman, and N. E. Reist Ca2+-Dependent, Phospholipid-Binding Residues of Synaptotagmin Are Critical for Excitation-Secretion Coupling In Vivo J. Neurosci., July 23, 2008; 28(30): 7458 - 7466. [Abstract] [Full Text] [PDF]

				R. Friedrich, A. J. Groffen, E. Connell, J. R. T. van Weering, O. Gutman, Y. I. Henis, B. Davletov, and U. Ashery DOC2B Acts as a Calcium Switch and Enhances Vesicle Fusion J. Neurosci., July 2, 2008; 28(27): 6794 - 6806. [Abstract] [Full Text] [PDF]

				J.-S. Schonn, A. Maximov, Y. Lao, T. C. Sudhof, and J. B. Sorensen Synaptotagmin-1 and -7 are functionally overlapping Ca2+ sensors for exocytosis in adrenal chromaffin cells PNAS, March 11, 2008; 105(10): 3998 - 4003. [Abstract] [Full Text] [PDF]

				Y. Yang, T. J. Craig, X. Chen, L. F. Ciufo, M. Takahashi, A. Morgan, and K. D. Gillis Phosphomimetic Mutation of Ser-187 of SNAP-25 Increases both Syntaxin Binding and Highly Ca2+-sensitive Exocytosis J. Gen. Physiol., March 26, 2007; 129(3): 233 - 244. [Abstract] [Full Text] [PDF]

				K. L. Lynch and T. F. J. Martin Synaptotagmins I and IX function redundantly in regulated exocytosis but not endocytosis in PC12 cells J. Cell Sci., February 15, 2007; 120(4): 617 - 627. [Abstract] [Full Text] [PDF]

				J. A. Kertz, P. F. F. Almeida, A. A. Frazier, A. K. Berg, and A. Hinderliter The Cooperative Response of Synaptotagmin I C2A. A Hypothesis for a Ca2+-Driven Molecular Hammer Biophys. J., February 15, 2007; 92(4): 1409 - 1418. [Abstract] [Full Text] [PDF]

				Z. P. Pang, O.-H. Shin, A. C. Meyer, C. Rosenmund, and T. C. Sudhof A Gain-of-Function Mutation in Synaptotagmin-1 Reveals a Critical Role of Ca2+-Dependent Soluble N-Ethylmaleimide-Sensitive Factor Attachment Protein Receptor Complex Binding in Synaptic Exocytosis J. Neurosci., November 29, 2006; 26(48): 12556 - 12565. [Abstract] [Full Text] [PDF]

				C.-T. Wang, J. Bai, P. Y. Chang, E. R. Chapman, and M. B. Jackson Synaptotagmin-Ca2+ triggers two sequential steps in regulated exocytosis in rat PC12 cells: fusion pore opening and fusion pore dilation J. Physiol., January 15, 2006; 570(2): 295 - 307. [Abstract] [Full Text] [PDF]

				J. T. Ting, B. G. Kelley, and J. M. Sullivan Synaptotagmin IV Does Not Alter Excitatory Fast Synaptic Transmission or Fusion Pore Kinetics in Mammalian CNS Neurons J. Neurosci., January 11, 2006; 26(2): 372 - 380. [Abstract] [Full Text] [PDF]

				G. Nagy, J. H. Kim, Z. P. Pang, U. Matti, J. Rettig, T. C. Sudhof, and J. B. Sorensen Different Effects on Fast Exocytosis Induced by Synaptotagmin 1 and 2 Isoforms and Abundance But Not by Phosphorylation J. Neurosci., January 11, 2006; 26(2): 632 - 643. [Abstract] [Full Text] [PDF]

				I. Milosevic, J. B. Sorensen, T. Lang, M. Krauss, G. Nagy, V. Haucke, R. Jahn, and E. Neher Plasmalemmal Phosphatidylinositol-4,5-Bisphosphate Level Regulates the Releasable Vesicle Pool Size in Chromaffin Cells J. Neurosci., March 9, 2005; 25(10): 2557 - 2565. [Abstract] [Full Text] [PDF]

				W. Han, J.-S. Rhee, A. Maximov, W. Lin, R. E. Hammer, C. Rosenmund, and T. C. Sudhof C-terminal ECFP Fusion Impairs Synaptotagmin 1 Function: CROWDING OUT SYNAPTOTAGMIN 1 J. Biol. Chem., February 11, 2005; 280(6): 5089 - 5100. [Abstract] [Full Text] [PDF]

				A. Mezer, E. Nachliel, M. Gutman, and U. Ashery A New Platform to Study the Molecular Mechanisms of Exocytosis J. Neurosci., October 6, 2004; 24(40): 8838 - 8846. [Abstract] [Full Text] [PDF]

				T.-i. Nishiki and G. J. Augustine Synaptotagmin I Synchronizes Transmitter Release in Mouse Hippocampal Neurons J. Neurosci., July 7, 2004; 24(27): 6127 - 6132. [Abstract] [Full Text] [PDF]

				M. R. Bennett, L. Farnell, and W. G. Gibson The Facilitated Probability of Quantal Secretion within an Array of Calcium Channels of an Active Zone at the Amphibian Neuromuscular Junction Biophys. J., May 1, 2004; 86(5): 2674 - 2690. [Abstract] [Full Text] [PDF]

				O.-H. Shin, A. Maximov, B. K. Lim, J. Rizo, and T. C. Sudhof Unexpected Ca2+-binding properties of synaptotagmin 9 PNAS, February 24, 2004; 101(8): 2554 - 2559. [Abstract] [Full Text] [PDF]

				O. Yizhar, U. Matti, R. Melamed, Y. Hagalili, D. Bruns, J. Rettig, and U. Ashery Tomosyn inhibits priming of large dense-core vesicles in a calcium-dependent manner PNAS, February 24, 2004; 101(8): 2578 - 2583. [Abstract] [Full Text] [PDF]

				M. Lindau Synaptotagmin Function Illuminated J. Gen. Physiol., August 25, 2003; 122(3): 251 - 254. [Full Text] [PDF]

Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents