| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
* A. N. Frumkin Institute of Electrochemistry, Russian Academy of Sciences, Moscow, Russia; A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia; and Laboratory of Cellular and Molecular Biophysics, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
Correspondence: Address reprint requests to Joshua Zimmerberg, NIH 10/10D14, 10 Center Dr., SC 1855, Bethesda, MD 20892-1855. Tel.: 301-496-6571; Fax: 301-594-0813; E-mail: Joshz{at}helix.nih.gov.
While biological membrane fusion is classically defined as the leak-free merger of membranes and contents, leakage is a finding in both experimental and theoretical studies. The fusion stages, if any, that allow membrane permeation are uncharted. In this study we monitored membrane ionic permeability at early stages of fusion mediated by the fusogenic protein influenza hemagglutinin (HA). HAb2 cells, expressing HA on their plasma membrane, fused with human red blood cells, cultured liver cells PLC/PRF/5, or planar phospholipid bilayer membranes. With a probability that depended upon the target membrane, an increase of the electrical conductance of the fusing membranes (leakage) by up to several nS was generally detected. This leakage was recorded at the initial stages of fusion, when fusion pores formed. This leakage usually accompanied the "flickering" stage of the early fusion pore development. As the pore widened, the leakage reduced; concomitantly, the lipid exchange between the fusing membranes accelerated. We conclude that during fusion pore formation, HA locally and temporarily increases the permeability of fusing membranes. Subsequent rearrangement in the fusion complex leads to the resealing of the leaky membranes and enlargement of the pore.
This article has been cited by other articles:
 |
|
 |
|
  A. Engel and P. Walter Membrane lysis during biological membrane fusion: collateral damage by misregulated fusion machines J. Cell Biol., October 20, 2008; 183(2): 181 - 186. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Biswas, S.-R. Yin, P. S. Blank, and J. Zimmerberg Cholesterol Promotes Hemifusion and Pore Widening in Membrane Fusion Induced by Influenza Hemagglutinin J. Gen. Physiol., May 1, 2008; 131(5): 503 - 513. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Cacela and D. K. Hincha Low Amounts of Sucrose Are Sufficient to Depress the Phase Transition Temperature of Dry Phosphatidylcholine, but Not for Lyoprotection of Liposomes Biophys. J., April 15, 2006; 90(8): 2831 - 2842. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X. Chen, D. Arac, T.-M. Wang, C. J. Gilpin, J. Zimmerberg, and J. Rizo SNARE-Mediated Lipid Mixing Depends on the Physical State of the Vesicles Biophys. J., March 15, 2006; 90(6): 2062 - 2074. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Katsov, M. Muller, and M. Schick Field Theoretic Study of Bilayer Membrane Fusion: II. Mechanism of a Stalk-Hole Complex Biophys. J., February 1, 2006; 90(3): 915 - 926. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Jin, C. Carlile, S. Nolan, and E. Grote Prm1 Prevents Contact-Dependent Lysis of Yeast Mating Pairs Eukaryot. Cell, December 1, 2004; 3(6): 1664 - 1673. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Katsov, M. Muller, and M. Schick Field Theoretic Study of Bilayer Membrane Fusion. I. Hemifusion Mechanism Biophys. J., November 1, 2004; 87(5): 3277 - 3290. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. J. Merz and W. T. Wickner Trans-SNARE interactions elicit Ca2+ efflux from the yeast vacuole lumen J. Cell Biol., January 19, 2004; 164(2): 195 - 206. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
