InterPro : IPR002369

Name  Integrin beta subunit, N-terminal Short Name  Integrin_bsu_N
Type  Domain Description  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 [, ]. The integrin receptors are composed of alpha and beta subunit heterodimers. 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 []. There are at least 18 types of alpha and 8 types of beta subunits recognised in humans []. Each alpha subunit tends to associate only with one type of beta subunit, but there are exceptions to this rule []. 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.Integrins are important therapeutic targets in conditions such as atherosclerosis, thrombosis, cancer and asthma [].At the N terminus of the beta subunit is a cysteine-containing domain reminiscent of that found in presenillins and semaphorins, which has hence been termed the PSI domain. C-terminal to the PSI domain is an A-domain, which has been predicted to adopt a Rossmann fold similar to that of the alpha subunit, but with additional loops between the second and third beta strands []. The murine gene Pactolus shares significant similarity with the beta subunit [], but lacks either one or both of the inserted loops. The C-terminal portion of the beta subunit extracellular domain contains an internally disulphide-bonded cysteine-rich region, while the intracellular tail contains putative sites of interaction with a variety of intracellular signalling and cytoskeletal proteins, such as focal adhesion kinase and alpha-actinin respectively []. Integrin cytoplasmic domains are normally less than 50 amino acids in length, with the beta-subunit sequences exhibiting greater homology to each other than the alpha-subunit sequences. This is consistent with current evidence that the beta subunit is the principal site for binding of cytoskeletal and signalling molecules, whereas the alpha subunit has a regulatory role. The first 20 amino acids of the beta-subunit cytoplasmic domain are also alpha helical, but the final 25 residues are disordered and, apart from a turn that follows a conserved NPxY motif, appear to lack defined structure, suggesting that this is adopted on effector binding. The two membrane-proximal helices mediate the link between the subunits via a series of hydrophobic and electrostatic contacts.This entry represents the N-terminal portion of the extracellular region of integrin beta subunits.

Sequence Features

GO Displayer


InterPro protein domain ID --> Contigs



0 Child Features

0 Contains

6 Found In

Id Name Short Name Type
IPR015812 Integrin beta subunit Integrin_bsu Family
IPR015437 Integrin beta-7 subunit Integrin_bsu-7 Family
IPR012013 Integrin beta-4 subunit Integrin_bsu-4 Family
IPR015436 Integrin beta-6 subunit Integrin_bsu-6 Family
IPR015439 Integrin beta-2 subunit Integrin_bsu-2 Family
IPR015442 Integrin beta-8 subunit Integrin_bsu-8 Family

0 Parent Features

9 Publications

First Author Title Year Journal Volume Pages
Albelda SM Integrins and other cell adhesion molecules. 1990 FASEB J 4 2868-80
Hynes RO Integrins: bidirectional, allosteric signaling machines. 2002 Cell 110 673-87
Demetriou MC Integrin clipping: a novel adhesion switch? 2004 J Cell Biochem 91 26-35
Cheresh DA A novel vitronectin receptor integrin (alpha v beta x) is responsible for distinct adhesive properties of carcinoma cells. 1989 Cell 57 59-69
Bökel C Integrins in development: moving on, responding to, and sticking to the extracellular matrix. 2002 Dev Cell 3 311-21
Arnaout MA Integrin structure: new twists and turns in dynamic cell adhesion. 2002 Immunol Rev 186 125-40
Tuckwell DS A structure prediction for the ligand-binding region of the integrin beta subunit: evidence for the presence of a von Willebrand factor A domain. 1997 FEBS Lett 400 297-303
Chen Y Identification of pactolus, an integrin beta subunit-like cell-surface protein preferentially expressed by cells of the bone marrow. 1998 J Biol Chem 273 8711-8
Hemler ME Integrin associated proteins. 1998 Curr Opin Cell Biol 10 578-85

To cite PlanMine, please refer to the following publication:

Rozanski, A., Moon, H., Brandl, H., Martín-Durán, J. M., Grohme, M., Hüttner, K., Bartscherer, K., Henry, I., & Rink, J. C.
PlanMine 3.0—improvements to a mineable resource of flatworm biology and biodiversity
Nucleic Acids Research, gky1070. doi:10.1093/nar/gky1070 (2018)