scholarly journals Analysis of rhodamine and fluorescein-labeled F-actin diffusion in vitro by fluorescence photobleaching recovery

1988 ◽  
Vol 54 (5) ◽  
pp. 801-815 ◽  
Author(s):  
J.R. Simon ◽  
A. Gough ◽  
E. Urbanik ◽  
F. Wang ◽  
F. Lanni ◽  
...  
Keyword(s):  
Fluorescence Photobleaching Recovery ◽  
Photobleaching Recovery

scholarly journals The dynamic distribution of fluorescent analogues of actin and myosin in protrusions at the leading edge of migrating Swiss 3T3 fibroblasts.

1988 ◽  
Vol 107 (6) ◽  
pp. 2631-2645 ◽  
Author(s):  
R L DeBiasio ◽  
L L Wang ◽  
G W Fisher ◽  
D L Taylor
Keyword(s):  
Leading Edge ◽  
Parameter Analysis ◽  
3T3 Fibroblasts ◽  
Fluorescence Photobleaching Recovery ◽  
Photobleaching Recovery ◽  
Ratio Imaging ◽  
Low Levels ◽  
Sequential Images ◽  
Swiss 3T3 Fibroblasts

The formation of protrusions at the leading edge of the cell is an essential step in fibroblast locomotion. Using fluorescent analogue cytochemistry, ratio imaging, multiple parameter analysis, and fluorescence photobleaching recovery, the distribution of actin and myosin was examined in the same protrusions at the leading edge of live, locomoting cells during wound-healing in vitro. We have previously defined two temporal stages of the formation of protrusions: (a) initial protrusion and (b) established protrusion (Fisher et al., 1988). Actin was slightly concentrated in initial protrusions, while myosin was either totally absent or present at extremely low levels at the base of the initial protrusions. In contrast, established protrusions contained diffuse actin and actin microspikes, as well as myosin in both diffuse and structured forms. Actin and myosin were also localized along concave transverse fibers near the base of initial and established protrusions. The dynamics of myosin penetration into a relatively stable, established protrusion was demonstrated by recording sequential images over time. Myosin was shown to be absent from an initial protrusion, but diffuse and punctate myosin was detected in the same protrusion within 1-2 min. Fluorescence photobleaching recovery indicated that myosin was 100% immobile in the region behind the leading edge containing transverse fibers, in comparison to the 21% immobile fraction detected in the perinuclear region. Possible explanations of the delayed penetration of myosin into established protrusions and the implications on the mechanism of protrusion are discussed.

What do nanometer molecular trajectories tell us about heterogeneous cell surface domaines?

1995 ◽  
Vol 53 ◽  
pp. 786-787
Author(s):  
Watt W. Webb
Keyword(s):  
Cell Surface ◽  
Lipid Membranes ◽  
Surface Proteins ◽  
Protein Diffusion ◽  
Coated Pits ◽  
Cell Surface Proteins ◽  
Membrane Heterogeneity ◽  
Fluorescence Photobleaching Recovery ◽  
Photobleaching Recovery ◽  
Plasma Membrane Heterogeneity

Plasma membrane heterogeneity is implicit in the existence of specialized cell surface organelles which are necessary for cellular function; coated pits, post and pre-synaptic terminals, microvillae, caveolae, tight junctions, focal contacts and endothelial polarization are examples. The persistence of these discrete molecular aggregates depends on localized restraint of the constituent molecules within specific domaines in the cell surface by strong intermolecular bonds and/or anchorage to extended cytoskeleton. The observed plasticity of many of organelles and the dynamical modulation of domaines induced by cellular signaling evidence evanescent intermolecular interactions even in conspicuous aggregates. There is also strong evidence that universal restraints on the mobility of cell surface proteins persist virtually everywhere in cell surfaces, not only in the discrete organelles. Diffusion of cell surface proteins is slowed by several orders of magnitude relative to corresponding protein diffusion coefficients in isolated lipid membranes as has been determined by various ensemble average methods of measurement such as fluorescence photobleaching recovery(FPR).

scholarly journals A factor from neurons induces partial immobilization of nonclustered acetylcholine receptors on cultured muscle cells.

1981 ◽  
Vol 88 (2) ◽  
pp. 459-462 ◽  
Author(s):  
D Axelrod ◽  
H C Bauer ◽  
M Stya ◽  
C N Christian
Keyword(s):  
Conditioned Medium ◽  
Acetylcholine Receptors ◽  
Glioma Cell ◽  
Primary Cultures ◽  
Glioma Cell Line ◽  
Continuous Treatment ◽  
Hybrid Cells ◽  
Fluorescence Photobleaching Recovery ◽  
Photobleaching Recovery ◽  
Alpha Bungarotoxin

A factor or factors released by cultured NG108-15 neuroblastoma X glioma hybrid cells and added to the medium of rat myotube primary cultures was found to immobilize some of the previously mobile acetylcholine receptors in the myotube membrane. Partial receptor immobilization occurred within 3 h after the beginning of treatment with the NG108-15-conditioned medium factor and persisted for at least 24 h of continuous treatment. A similarly derived conditioned medium concentrate from the non-neuronal parent glioma cell line did not immobilize receptors, relative to untreated controls. Acetylcholine receptors were visualized by fluorescent alpha-bungarotoxin and their lateral motion was observed by the technique of fluorescence photobleaching recovery.

Sign in / Sign up

Export Citation Format

Share Document