Document Detail


Characteristics of a membrane reservoir buffering membrane tension.
MedLine Citation:
PMID:  10512819     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
When membrane-attached beads are pulled vertically by a laser tweezers, a membrane tube of constant diameter (tether) is formed. We found that the force on the bead (tether force) did not depend on tether length over a wide range of tether lengths, which indicates that a previously unidentified reservoir of membrane and not stretch of the plasma membrane provides the tether membrane. Plots of tether force vs. tether length have an initial phase, an elongation phase, and an exponential phase. During the major elongation phase, tether force is constant, buffered by the "membrane reservoir." Finally, there is an abrupt exponential rise in force that brings the tether out of the trap, indicating depletion of the membrane reservoir. In chick embryo fibroblasts and 3T3 fibroblasts, the maximum tether lengths that can be pulled at a velocity of 4 microm/s are 5.1 +/- 0. 3 and 5.0 +/- 0.2 microm, respectively. To examine the importance of the actin cytoskeleton, we treated cells with cytochalasin B or D and found that the tether lengths increased dramatically to 13.8 +/- 0.8 and 12.0 +/- 0.7 microm, respectively. Similarly, treatment of the cells with colchicine and nocodazole results in more than a twofold increase in tether length. We found that elevation of membrane tension (through osmotic pressure, a long-term elevation of tether force, or a number of transitory increases) increased reservoir size over the whole cell. Using a tracking system to hold tether force on the bead constant near its maximal length in the exponential phase, the rate of elongation of the tethers was measured as a function of tether force (membrane tension). The rate of elongation of tethers was linearly dependent on the tether force and reflected an increase in size of the reservoir. Increases in the reservoir caused by tension increases on one side of the cell caused increases in reservoir size on the other side of the cell. Thus, we suggest that cells maintain a plasma membrane reservoir to buffer against changes in membrane tension and that the reservoir is increased with membrane tension or disruption of the cytoskeleton.
Authors:
D Raucher; M P Sheetz
Related Documents :
9299109 - In vitro study of the protective effect of trehalose and dextran during freezing of hum...
7153459 - Evaluation of density gradient separation methods.
19540949 - Red blood cell (rbc) membrane proteomics--part i: proteomics and rbc physiology.
9806729 - The diagnostic relevance of red cell rigidity.
21031149 - Shapes of red blood cells: comparison of 3d confocal images with the bilayer-couple model.
3254109 - Some effects on light scattering intensity and red blood cell size distribution histogr...
2346229 - Quantitative analysis of the retrograde reaction of motoneurons with an image analyser.
16112089 - Spatiotemporal quantification of recruit and resident macrophages after crush nerve inj...
11385579 - Mor1 is essential for organizing cortical microtubules in plants.
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Biophysical journal     Volume:  77     ISSN:  0006-3495     ISO Abbreviation:  Biophys. J.     Publication Date:  1999 Oct 
Date Detail:
Created Date:  1999-11-22     Completed Date:  1999-11-22     Revised Date:  2009-11-18    
Medline Journal Info:
Nlm Unique ID:  0370626     Medline TA:  Biophys J     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1992-2002     Citation Subset:  IM    
Affiliation:
Department of Cell Biology, Duke University Medical Center, Durham, North Carolina 27710 USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
3T3 Cells
Actins / physiology
Animals
Cell Membrane / drug effects,  metabolism,  physiology*
Cell Size / drug effects
Chick Embryo
Colchicine / pharmacology
Cytochalasins / pharmacology
Cytoskeleton / drug effects,  physiology
Fibroblasts / cytology*,  drug effects
Hypotonic Solutions
Kinetics
Lasers
Mice
Microspheres
Nocodazole / pharmacology
Osmolar Concentration
Osmotic Pressure
Physical Stimulation
Chemical
Reg. No./Substance:
0/Actins; 0/Cytochalasins; 0/Hypotonic Solutions; 31430-18-9/Nocodazole; 64-86-8/Colchicine
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Two-microelectrode voltage clamp of Xenopus oocytes: voltage errors and compensation for local curre...
Next Document:  Membrane fusion and the lamellar-to-inverted-hexagonal phase transition in cardiolipin vesicle syste...