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Biophysics of Proteins at Surfaces: Assembly, Activation, Signaling
Tuesday Speaker Abstracts
E-cadherin Junction Formation Involves an Active Kinetic Nucleation Process
Kabir Biswas
1
, Kevin L. Hartman
1,2
, Cheng-Han Yu
1
, Oliver J. Harrison
3,4,9
, Hang Song
3,4,9
,
Adam W. Smith
5
, William Huang
2
, Wan-Chen Lin
5
, Zhenhuan Guo
1
, Anup Padmanabhan
1
,
Sergey M. Troyanovsky
7
, Michael L. Dustin
8
, Lawrence Shapiro
3,9
, Barry Honig
3,4,9
, Ronen
Zaidel-Bar
1,10
, Jay T. Groves
1,2,5
.
1
National University of Singapore, Singapore, Singapore,
2
University of California, Berkeley,
Berkeley, CA, USA,
3
Columbia University, New York, NY, USA,
4
Columbia University, New
York, NY, USA,
5
University of California, Berkeley, Berkeley, CA, USA,
6
Lawrence Berkeley
National Laboratory, University of California, Berkeley, CA, USA,
7
Feinberg School of
Medicine, Northwestern University, Chicago, IL, USA,
8
University of Oxford, Headington,
United Kingdom,
9
Columbia University, New York, NY, USA,
10
National University of
Singapore, Singapore, Singapore.
E-cadherin-mediated cell-cell junctions play important roles in the development and maintenance
of tissue structure in multi-cellular organisms. E-cadherin adhesion is thus a key element of the
cellular microenvironment that provides both mechanical and biochemical signaling inputs.
Here, we report in vitro reconstitution of junction-like structures between native E-cadherin in
living cells and the extracellular domain of E-cadherin (E-cad-ECD) in a supported membrane.
Junction formation in this hybrid live cell-supported membrane configuration requires both
active processes within the living cell and a supported membrane with low E-cad-ECD mobility.
The hybrid junctions recruit α-catenin, and exhibit remodeled cortical actin. Observations
suggest that the initial stages of junction formation in this hybrid system depend on the trans but
not the cis-interactions between E-cadherin molecules, and proceed via a nucleation process in
which protrusion and retraction of filopodia play a key role.