title: E-cadherin interactome complexity and robustness resolved by quantitative proteomics.
abstract: E-cadherin-mediated cell-cell adhesion and signaling plays an essential role in development and maintenance of healthy epithelial tissues. Adhesiveness mediated by E-cadherin is conferred by its extracellular cadherin domains and is regulated by an assembly of intracellular adaptors and enzymes associated with its cytoplasmic tail. We used proximity biotinylation and quantitative proteomics to identify 561 proteins in the vicinity of the cytoplasmic tail of E-cadherin. In addition, we used proteomics to identify proteins associated with E-cadherin-containing adhesion plaques from a cell-glass interface, which enabled the assignment of cellular localization to putative E-cadherin-interacting proteins. Moreover, by tagging identified proteins with GFP (green fluorescent protein), we determined the subcellular localization of 83 putative E-cadherin-proximal proteins and identified 24 proteins that were previously uncharacterized as part of adherens junctions. We constructed and characterized a comprehensive E-cadherin interaction network of 79 published and 394 previously uncharacterized proteins using a structure-informed database of protein-protein interactions. Finally, we found that calcium chelation, which disrupts the interaction of the extracellular E-cadherin domains, did not disrupt most intracellular protein interactions with E-cadherin, suggesting that the E-cadherin intracellular interactome is predominantly independent of cell-cell adhesion.
authors.affiliation: Mechanobiology Institute of Singapore, National University of Singapore, Singapore 117411, Singapore.
authors.forename: Zhenhuan
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Vascular Proteomics Laboratory, Cancer Research UK Beatson Institute, Glasgow G61 1BD, UK.
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Neilson
authors.affiliation: Mechanobiology Institute of Singapore, National University of Singapore, Singapore 117411, Singapore.
authors.forename: Hang
authors.initials: H
authors.lastname: Zhong
authors.affiliation: Departments of Biochemistry and Molecular Biophysics and Systems Biology, and Center of Computational Biology and Bioinformatics, Columbia University, New York, NY 10032, USA.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Murray
authors.affiliation: Vascular Proteomics Laboratory, Cancer Research UK Beatson Institute, Glasgow G61 1BD, UK.
authors.forename: Sara
authors.initials: S
authors.lastname: Zanivan
authors.affiliation: Mechanobiology Institute of Singapore, National University of Singapore, Singapore 117411, Singapore. Department of Biomedical Engineering, National University of Singapore, Singapore 117575, Singapore. biezbr@nus.edu.sg.
authors.forename: Ronen
authors.initials: R
authors.lastname: Zaidel-Bar
mesh_terms: D015820:Cadherins / Q000378:metabolism*; D065096:Calcium Chelating Agents / Q000378:metabolism; D019731:Carbon-Nitrogen Ligases; D002448:Cell Adhesion / Q000502:physiology*; D045744:Cell Line, Tumor; D019295:Computational Biology; D004848:Epithelium / Q000254:growth & development*; D029968:Escherichia coli Proteins; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D013058:Mass Spectrometry; D018613:Microscopy, Confocal; D025941:Protein Interaction Mapping / Q000379:methods*; D040901:Proteomics / Q000379:methods*; D012097:Repressor Proteins
chemical_list: D015820:Cadherins; D065096:Calcium Chelating Agents; D029968:Escherichia coli Proteins; D012097:Repressor Proteins; D049452:Green Fluorescent Proteins; D019731:Carbon-Nitrogen Ligases; C058125:birA protein, E coli