Nucleation and growth of cadherin adhesions
Experimental Cell Research. 2007-11-01; 313(19): 4025-4040
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1. Exp Cell Res. 2007 Nov 15;313(19):4025-40. Epub 2007 Aug 8.
Nucleation and growth of cadherin adhesions.
Lambert M(1), Thoumine O, Brevier J, Choquet D, Riveline D, Mège RM.
(1)INSERM, U839, Paris, F-75005, France.
Cell-cell contact formation relies on the recruitment of cadherin molecules and
their anchoring to actin. However, the precise chronology of events from initial
cadherin trans-interactions to adhesion strengthening is unclear, in part due to
the lack of access to the distribution of cadherins within adhesion zones. Using
N-cadherin expressing cells interacting with N-cadherin coated surfaces, we
characterized the formation of cadherin adhesions at the ventral cell surface.
TIRF and RIC microscopies revealed streak-like accumulations of cadherin along
actin fibers. FRAP analysis indicated that engaged cadherins display a slow
turnover at equilibrium, compatible with a continuous addition and removal of
cadherin molecules within the adhesive contact. Association of cadherin
cytoplasmic tail to actin as well as actin cables and myosin II activity are
required for the formation and maintenance of cadherin adhesions. Using time
lapse microscopy we deciphered how cadherin adhesions form and grow. As
lamellipodia protrude, cadherin foci stochastically formed a few microns away
from the cell margin. Neo-formed foci coalesced aligned and coalesced with
preformed foci either by rearward sliding or gap filling to form cadherin
adhesions. Foci experienced collapse at the rear of cadherin adhesions. Based on
these results, we present a model for the nucleation, directional growth and
shrinkage of cadherin adhesions.
PMID: 17765222 [Indexed for MEDLINE]