The time course and pattern of incorporation of rhodamine-labeled actin microinjected into cultured fibroblastic cells were examined by fluorescence microscopy. Following microinjection, the fluorescent probe was incorporated rapidly into ruffling membranes, and within 5 min faintly fluorescent stress fibers were observed. Levels of fluorescence in ruffling membranes then tended to remain constant while fluorescence of the stress fibers continued to increase until approximately 20-min postinjection. Small, discrete regions of some microinjected cells displayed high levels of fluorescence that appeared initially approximately 5-10 min postinjection. I observed these small areas of intense fluorescence frequently near the cell periphery, which corresponded to focal contacts when examined with interference reflection optics. The results of this study show that a relationship exists between patterns of fluorescent actin incorporation in these cells and cellular areas or structures presumed to play a role in cell movement. These findings suggest that actin within stress fibers and the microfilament network of ruffling membranes undergoes a rapid turnover that may relate directly to the motility of the cell.
Article| October 01 1983
Subcellular distribution of rhodamine-actin microinjected into living fibroblastic cells.
S D Glacy
Online ISSN: 1540-8140
Print ISSN: 0021-9525
J Cell Biol (1983) 97 (4): 1207–1213.
S D Glacy; Subcellular distribution of rhodamine-actin microinjected into living fibroblastic cells.. J Cell Biol 1 October 1983; 97 (4): 1207–1213. doi: https://doi.org/10.1083/jcb.97.4.1207
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