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Identification of a tetrapeptide recognition sequence for the alpha 2 beta 1 integrin in collagen
W D Staatz1, K F Fok, M M Zutter
1Department of Pathology, Washington University School of Medicine, St. Louis, Missouri 63110.
The Journal of Biological Chemistry
|April 25, 1991
Summary
The alpha 2 beta 1 integrin recognizes the Asp-Gly-Glu-Ala (DGEA) sequence in collagen. This tetrapeptide is key for cell adhesion to collagen and laminin substrates, as shown in platelet and cancer cell studies.
Area of Science:
- Cell Biology
- Biochemistry
- Molecular Biology
Background:
- The alpha 2 beta 1 integrin functions as a cell surface receptor for collagen and/or laminin, varying by cell type.
- Previous research identified a binding site within the alpha 1(I)-CB3 fragment of type I collagen for this integrin.
Purpose of the Study:
- To further define the specific amino acid sequence recognized by the alpha 2 beta 1 integrin.
- To investigate the role of this sequence in cell adhesion to collagen and laminin.
Main Methods:
- Synthesized overlapping peptides spanning the alpha 1(I)-CB3 fragment of type I collagen.
- Tested peptide inhibition of cell adhesion to collagen and laminin substrates.
- Utilized platelets and T47D breast adenocarcinoma cells to assess integrin-mediated adhesion.
Main Results:
- Identified a minimal active recognition sequence: Asp-Gly-Glu-Ala (DGEA), corresponding to residues 435-438 of type I collagen.
- DGEA-containing peptides inhibited alpha 2 beta 1-mediated platelet adhesion to collagen.
- DGEA peptides also inhibited alpha 2 beta 1-mediated adhesion of T47D cells to both collagen and laminin.
- Modifications to the DGEA sequence significantly reduced inhibitory activity.
Conclusions:
- The tetrapeptide sequence DGEA is a critical recognition site for the alpha 2 beta 1 integrin.
- This finding has implications for understanding cell-matrix interactions mediated by alpha 2 beta 1 integrin in various cell types.