Stress fiber reformation after XXXX depletion.

@entity10274 @entity855 @entity2277 @entity8859 @entity4627 @entity897
Fluorescently labeled heavy meromyosin, @entity8859 , and @entity10274 were used to localize actin, @entity8859 , and @entity10274 , respectively, in permeabilized and living cells during the process of stress fiber reassembly, which occurred when cells were removed from @entity855 -depleting medium (20 mM @entity4627 and 10 mM @entity897 ). In 80% of the cells recovering from @entity855 depletion, small, scattered plaques containing actin, @entity8859 , and @entity10274 were replaced by long, thin, periodic fibers within 5 minutes of removal of the inhibitors. These nascent stress fibers grew broader as recovery progressed, until they attained the thickness of stress fibers in control cells. In the other 20% of the cells, the scattered plaques aggregated within 5 minutes of reversal, and almost all the actin, @entity8859 , and @entity10274 in the cells became localized in one perinuclear aggregate, with a diameter of approximately 15-25 micron. As recovery progressed, all aggregates resembled rings, with diameters that increased at about 0.5 micron/minute and grew to as large as 70 micron in some giant cells. As the size of the rings increased, fibers radiated outward from them and sometimes spanned the diameter of the rings. The shape of the cells did not change during this time. By 1 hour after reversal, the rings were no longer present and all cells had networks of stress fibers. Indirect immunofluorescence techniques used to localize tubulin and @entity2277 indicated that microtubules and intermediate filaments were not constituents of the rings, and the rings were not closely apposed to the substrate, judging from reflection contrast optics. The rapid rearrangement of attachment plaques into a perinuclear aggregate that spreads radially in the cytoplasm occurs at the same speed as fibroblast and chromosomal movement, but is unlike other types of intracytoplasmic motility.
