TY - JOUR
T1 - Interaction of fibronectin-coated beads with attached and spread fibroblasts. Binding, phagocytosis, and cytoskeletal reorganization
AU - Grinnell, Frederick
AU - Geiger, Benjamin
N1 - Funding Information:
William Snell, and George Bloom provided helpful comments regarding the manuscript. Support was provided for this research by the NIH (Grant no. CA14609 to F. G.) and a grant from the Muscular Distrophy Association (to B. G.).
PY - 1986/2
Y1 - 1986/2
N2 - After 15 min incubations, binding of 0.8-, 6-, and 16-μm fibronectin-coated latex beads occurred primarily at the margins of chick embryo fibroblasts that previously were attached and spread on fibronectin-coated glass coverslips. Extensive phagocytosis of the smallest beads and some phagocytosis of the larger beads occurred within 2 h. Following binding of the 16-μm beads, there were no changes in overall cell shape or in the distribution of several cytoskeletal proteins. There was, however, a local accumulation of actin and α-actinin patches adjacent to the sites where the beads were bound. The formation of α-actinin patches could be detected with 6- or 16-μm beads shortly after initial bead binding to the cells, but a similar reorganization of α-actinin in response to the binding of 0.8-μm beads was not detected. The patches of α-actinin appeared to be associated with membrane ruffles, since such structures were observed by scanning electron microscopy (SEM) to be sites of cell interaction with 6- but not 0.8-μm beads. Also, two other cytoskeletal proteins normally absent from membrane ruffles, tropomyosin and vinculin, were not detected at the sites of cell-bead interaction. No reorganization of vinculin at the cell-bead interaction sites was observed even when the 16-μm beads remained bound at the cell surfaces for up to 6 h. Nevertheless, prominent vinculin plaques were observed at the marginal attachment sites on the ventral cell surfaces. Consequently, formation of mature focal adhesions may be restricted to linear regions of cell-substratum interaction.
AB - After 15 min incubations, binding of 0.8-, 6-, and 16-μm fibronectin-coated latex beads occurred primarily at the margins of chick embryo fibroblasts that previously were attached and spread on fibronectin-coated glass coverslips. Extensive phagocytosis of the smallest beads and some phagocytosis of the larger beads occurred within 2 h. Following binding of the 16-μm beads, there were no changes in overall cell shape or in the distribution of several cytoskeletal proteins. There was, however, a local accumulation of actin and α-actinin patches adjacent to the sites where the beads were bound. The formation of α-actinin patches could be detected with 6- or 16-μm beads shortly after initial bead binding to the cells, but a similar reorganization of α-actinin in response to the binding of 0.8-μm beads was not detected. The patches of α-actinin appeared to be associated with membrane ruffles, since such structures were observed by scanning electron microscopy (SEM) to be sites of cell interaction with 6- but not 0.8-μm beads. Also, two other cytoskeletal proteins normally absent from membrane ruffles, tropomyosin and vinculin, were not detected at the sites of cell-bead interaction. No reorganization of vinculin at the cell-bead interaction sites was observed even when the 16-μm beads remained bound at the cell surfaces for up to 6 h. Nevertheless, prominent vinculin plaques were observed at the marginal attachment sites on the ventral cell surfaces. Consequently, formation of mature focal adhesions may be restricted to linear regions of cell-substratum interaction.
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U2 - 10.1016/0014-4827(86)90349-6
DO - 10.1016/0014-4827(86)90349-6
M3 - Article
C2 - 3080317
AN - SCOPUS:0022671903
SN - 0014-4827
VL - 162
SP - 449
EP - 461
JO - Experimental Cell Research
JF - Experimental Cell Research
IS - 2
ER -