Structural and mechanical functions of integrins

Abstract

Integrins are ubiquitously expressed cell surface receptors that play a critical role in regulating the interaction between a cell and its microenvironment to control cell fate. These molecules are regulated either via their expression on the cell surface or through a unique bidirectional signalling mechanism. However, integrins are just the tip of the adhesome iceberg, initiating the assembly of a large range of adaptor and signalling proteins that mediate the structural and signalling functions of integrin. In this review, we summarise the structure of integrins and mechanisms by which integrin activation is controlled. The different adhesion structures formed by integrins are discussed, as well as the mechanical and structural roles integrins play during cell migration. As the function of integrin signalling can be quite varied based on cell type and context, an in depth understanding of these processes will aid our understanding of aberrant adhesion and migration, which is often associated with human pathologies such as cancer.

Keywords: Extracellular matrix; Focal adhesion; Inside–out signalling; Integrins; Migration; Outside–in signalling.

Fig. 1

Integrin structure and activation model. a Schematic of the domain structure of the α- and β-subunit. b The model of integrin heterodimer activation from resting to ligand occupied. EGF Epidermal growth factor, PSI plexin–semaphorin–integrin domain

Fig. 2

Overview of structures involved in cell adhesion and migration. Schematic of the different cellular structures used during adhesion and migration