Related Experiment Videos
EWI-2 regulates alpha3beta1 integrin-dependent cell functions on laminin-5
Christopher S Stipp1, Tatiana V Kolesnikova, Martin E Hemler
1Dana-Farber Cancer Institute, Department of Pathology, Harvard Medical School, Boston, MA 02115, USA.
The Journal of Cell Biology
|December 10, 2003
Summary
EWI-2 protein, associated with CD9 and CD81, impairs cell migration by linking to alpha3beta1 integrin. Tetraspanins CD9 and CD81 mediate this EWI-2 and integrin interaction, affecting cell motility.
Area of Science:
- Cell Biology
- Molecular Biology
- Integrin Signaling
Background:
- EWI-2 is a cell surface protein with an unknown function.
- EWI-2 associates with tetraspanins CD9 and CD81.
- The functional role of EWI-2 in cell adhesion and migration is not well understood.
Purpose of the Study:
- To investigate the function of EWI-2 in cell adhesion, reaggregation, and motility.
- To determine the interaction of EWI-2 with integrins and tetraspanins.
- To elucidate the mechanism by which EWI-2 regulates cell functions.
Main Methods:
- Overexpression of EWI-2 in A431 epidermoid carcinoma cells.
- Cell adhesion, spreading, and reaggregation assays on different extracellular matrix proteins.
- Immunodepletion and reexpression experiments to study protein interactions.
- Analysis of EWI-2 localization and complex formation with CD81 and alpha3beta1 integrin.
Main Results:
- EWI-2 overexpression impaired A431 cell reaggregation and motility on laminin-5 (alpha3beta1 integrin ligand).
- Tetraspanins CD9 and CD81 were found to physically link EWI-2 to alpha3beta1 integrin.
- CD81 regulated EWI-2 maturation and cell surface localization, and its redistribution to filopodia upon EWI-2 overexpression.
- An EWI-2 mutant lacking these interactions did not affect cell migration.
Conclusions:
- EWI-2 laterally associates with alpha3beta1 integrin via tetraspanins CD9 and CD81, regulating cell motility.
- Tetraspanins play a crucial role in assembling EWI-2 and integrin into functional complexes.
- These findings provide insights into EWI-2 function in cellular processes and potential roles in disease and development.