Integrin beta-4 subunit (IPR012013)

Short name: Integrin_bsu-4

Overlapping homologous superfamilies

Family relationships


Integrins are the major metazoan receptors for cell adhesion to extracellular matrix proteins and, in vertebrates, also play important roles in certain cell-cell adhesions, make transmembrane connections to the cytoskeleton and activate many intracellular signalling pathways [PMID: 12297042, PMID: 12361595]. An integrin receptor is a heterodimer composed of alpha and beta subunits. Each subunit crosses the membrane once, with most of the polypeptide residing in the extracellular space, and has two short cytoplasmic domains. Some members of this family have EGF repeats at the C terminus and also have a vWA domain inserted within the integrin domain at the N terminus.

Most integrins recognise relatively short peptide motifs, and in general require an acidic amino acid to be present. Ligand specificity depends upon both the alpha and beta subunits [PMID: 12234368]. There are at least 18 types of alpha and 8 types of beta subunits recognised in humans [PMID: 14689578]. Each alpha subunit tends to associate only with one type of beta subunit, but there are exceptions to this rule [PMID: 2467745]. Each association of alpha and beta subunits has its own binding specificity and signalling properties. Many integrins require activation on the cell surface before they can bind ligands. Integrins frequently intercommunicate, and binding at one integrin receptor activate or inhibit another.

The beta 4 subunit differs from other beta subunits in three ways: 1) the cytoplasmic domain is larger; 2) it lacks some of the conserved cysteines in the extracellular domain; and 3) it has a unique domain organisation.

Integrin alpha-6/beta-4 is a receptor for laminin. It plays a critical structural role in the hemidesmosome of epithelial cells [PMID: 12482924]. Integrin beta-4 is required for the regulation of keratinocyte polarity and motility [PMID: 19403692].

For additional information please see [PMID: 2542022, PMID: 9402004, PMID: 9166594, PMID: 1976638, PMID: 2311577, PMID: 15157503, PMID: 2311578, PMID: 7982032].

GO terms

Biological Process

GO:0048870 cell motility
GO:0007160 cell-matrix adhesion
GO:0031581 hemidesmosome assembly
GO:0007229 integrin-mediated signaling pathway

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0008305 integrin complex

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.