Biophysical Society Thematic Meeting - October 13-15, 2015

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.

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