The Journal of Cell Biology, Vol 80, 128-140, Copyright © 1979 by The Rockefeller University Press
Inhibition of intercellular adhesion by concanavalin A is associated with concanavalin A-mediated redistribution of surface receptors
PC Letourneau
The inhibition of adhesion between aggregates and layers of embryonic
retinal cells by concanavalin A (Con A) and Con A-mediated rearrangements
of Con A receptors on retinal cells were studied. A short incubation of
aggregates and layers with 10 micrograms/ml Con A substantially reduced
aggregate-to-layer adhesion in a subsequent assay without soluble lectin
present. This effect of Con A was dose- dependent, temperature-sensitive,
involved events subsequent to Con A binding, and was reduced by
cytochalasin B. The inhibition produced by succinylated Con A was
substantially increased by incubation with antibody to Con A. Visualization
of ConA- receptor complexes by fluorescence microscopy revealed that
binding of Con A induced clearing of Con A receptors from filopodia,
flattened regions of growth cones, and the edges of axons. This clearing
reaction was prevented by the same agents that reduced Con A's inhibition
of cell adhesion: low temperature, succinylation of Con A, or cytochalasin
B. Aggregate-layer adhesion was restored by releasing Con A at 37 degrees
C. Inhibitors of protein and ATP synthesis did not prevent recovery of
ability to make adhesions. However, release of Con A at lowered
temperatures did not prevent recovery. The results suggest that
intercellular adhesion is inhibited by events associated with
redistribution of Con A-receptor complexes on retinal cells.