Transmembrane receptors, cellular integrins

Integrins are a family of cellular transmembrane receptors that provide physical and biochemical bridges between components of the ECM (see... 

Cellular Activation. Chemokines are potent cell activators after binding to the appropriate G protein-linked, seven-transmembrane spanning receptors, chemokines elicit transient intracellular calcium flux, actin polymerization, oxidative burst with release of superoxide free radicals, exocytosis of secondary granule constituents, and increased avidity of integrins for their adhesion molecules (Dl, E2). 

In animals, the extracellular matrix helps organize cells Into tissues and coordinates their cellular functions by activating intracellular signaling pathways that control cell growth, proliferation, and gene expression. Many functions of the matrix require transmembrane adhesion receptors that bind directly to ECM components and that also Interact, through adapter proteins, with the cytoskeleton. The principal class of adhesion receptors that mediate cell-matrix adhesion are integrins, which were introduced in Section 6.2. However, other types of molecules also function as important adhesion receptors in some nonepithelial tissues. 

---