Divalent cations regulate the organization of integrins alpha v beta 3 and alpha v beta 5 on the cell surface
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Updated: Nov 4, 2026

A Flow Cytometry-Based High-Throughput Technique for Screening Integrin-Inhibitory Drugs
Published on: February 2, 2024
I Stuiver1, Z Ruggeri, J W Smith
1Department of Molecular and Experimental Medicine and Vascular Biology, Scripps Research Institute, La Jolla, California, USA.
Abstract:
Extracellular divalent cations are important regulators of integrin ligand binding activity. In this study we evaluated how divalent cations affect the organization of integrins into focal adhesion sites. Integrins alpha v beta 3 and alpha v beta 5 were compared because they share a high degree of structural homology and because both integrins mediate cell adhesion to vitronectin. On MG-63 osteosarcoma cells, we found that both the extent and pattern of integrin organization was regulated by the type of extracellular divalent ion. Integrin alpha v beta 3 organized in focal contacts when Mn2+ or Mg2+ was present, but not in Ca2+. In contrast, alpha v beta 5 organized in focal contacts only when Ca2+ or Mg2+ was present. Integrin alpha v beta 5 clustered in a centrally located punctate field on the ventral surface of the cell in the presence of Mn2+. These observations reveal a previously unappreciated role for divalent ions in regulating the organization of integrins into focal adhesion sites.
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