Publication year: 2011
Source: Current Opinion in Cell Biology, Available online 14 September 2011
Coert Margadant, Hanneke N Monsuur, Jim C Norman, Arnoud Sonnenberg
Integrin adhesion receptors are essential for the normal function of most multicellular organisms, and defective integrin activation or integrin signaling is associated with an array of pathological conditions. Integrins are regulated by conformational changes, clustering, and trafficking, and regulatory mechanisms differ strongly between individual integrins and between cell types. Whereas integrins in circulating blood cells are activated by an inside-out-induced conformational change that favors high-affinity ligand binding, β1-integrins in adherent cells can be activated by force or clustering. In addition, endocytosis and recycling play an important role in the regulation of integrin turnover and integrin redistribution in adherent cells, especially during dynamic processes such as cell migration and invasion. Integrin trafficking is strongly regulated by their cytoplasmic tails, and the mechanisms are now being identified.
Highlights
► Integrin activation mechanisms differ between individual integrins. ► Integrin activation mechanisms differ for non-adherent and adherent cells. ► Integrins in adherent cells are strongly regulated by trafficking mechanisms. ► It is unclear how the NxxY motifs in the β-cytoplasmic tails regulate integrin trafficking. ► The α-subunits are important regulators of integrin trafficking.