What is ligand binding to integrins?

The integrins are a superfamily of cell adhesion receptors that bind to extracellular matrix ligands, cell-surface ligands, and soluble ligands.

What are the ligands for integrin receptors called?

Most of the ligands are ECM proteins containing one of the two motifs: arginine–glycine–aspartate (RGD) or leucine–aspartate–valine (LDV). Examples of integrin ligands are ICAM-1, which is present at the plasma membrane of antigen-presenting cells and binds to the integrin receptor LFA-1 to promote cell–cell adhesion.

Where does integrin activation occur?

Integrin can be activated from two directions, from the inside by the regulated binding of proteins to the cytoplasmic tails, and from the outside by multivalent ligand binding. In either case, talin binding to the integrin β tails is an essential and the final common step ([10], reviewed in [11]).

Which integrins are recognized as receptors for ligands containing RGD motif?

A subset of the integrins recognize the RGD motif within their ligands, the binding of which mediates both cell-substratum and cell-cell interactions. These integrins include αvβ3, α5β1 and αIIbβ3. The RGD domain is both sufficient and indispensable for cell membrane binding.

What does an integrin do?

Integrins regulate cellular growth, proliferation, migration, signaling, and cytokine activation and release and thereby play important roles in cell proliferation and migration, apoptosis, tissue repair, as well as in all processes critical to inflammation, infection, and angiogenesis.

Which integrins bind to RGD?

Why do integrin receptors bind to multiple ligands?

A characteristic feature of most integrin receptors is their ability to bind a wide variety of ligands. Conversely, many extracellular matrix and cell surface adhesion proteins bind to multiple integrin receptors (Humphries, 1990; Plow et al., 2000; van der Flier and Sonnenberg, 2001).

How do the αv integrins recognise RGD ligands?

All five αV integrins, two β1 integrins (α5, α8) and αIIbβ3 share the ability to recognise ligands containing an RGD tripeptide active site. Crystal structures of αVβ3 and αIIbβ3 complexed with RGD ligands have revealed an identical atomic basis for this interaction (Xiong et al., 2002; Xiao et al., 2004).

What are the 5 RGD binding integrins?

(a) RGD-binding integrins All five αV integrins, two β1 integrins (α5, α8) and αIIbβ3 share the ability to recognise ligands containing an RGD tripeptide active site. Crystal structures of αVβ3 and αIIbβ3 complexed with RGD ligands have revealed an identical atomic basis for this interaction (Xiong et al., 2002; Xiao et al., 2004).

How promiscuous are integrins in the receptor family?

The RGD-binding integrins are among the most promiscuous in the receptor family, with β3 integrins in particular binding to a large number of extracellular matrix and soluble vascular ligands.