Tenascin mediates cell attachment through an RGD-dependent receptor

Area of Science:

• Cell Biology
• Biochemistry
• Extracellular Matrix Research

Background:

• Tenascin is an extracellular matrix glycoprotein involved in development and tumor neovasculature.
• Its selective expression suggests a role in cell-matrix interactions.

Purpose of the Study:

• To investigate the mechanism of tenascin-mediated cell adhesion.
• To identify the cell surface receptor for tenascin.

Main Methods:

• Cell adhesion assays using various cell types (tumor cells, fibroblasts, endothelial cells).
• Mechanism studies with human glioma cells (U251MG) using RGD peptides.
• Affinity chromatography to isolate tenascin-binding proteins.
• SDS-PAGE and immunoblotting to characterize the receptor.

Main Results:

• Tenascin supports the adhesion of diverse cell types.
• Cell attachment to tenascin is inhibited by RGD peptides.
• A heterodimeric cell surface protein, the tenascin receptor, was isolated.
• This receptor is related to the fibronectin receptor, belonging to the integrin superfamily.

Conclusions:

• The tenascin receptor is identified as a member of the fibronectin receptor family within the integrin superfamily.
• Cellular responses to tenascin differ from fibronectin, indicating potential modulation of cell adhesion and motility.