CD18

Integrin, beta 2 (complement component 3 receptor 3 and 4 subunit)
PDB rendering based on 1l3y.
Available structures PDB 1JX3, 1L3Y, 1YUK, 2JF1, 2P26, 2P28, 2V7D, 3K6S, 3K71, 3K72
Identifiers
Symbols	ITGB2; CD18; LAD; LCAMB; LFA-1; MAC-1; MF17; MFI7
External IDs	OMIM: 600065 MGI: 96611 HomoloGene: 20092 GeneCards: ITGB2 Gene
Gene Ontology Molecular function • glycoprotein binding • receptor activity • protein binding • protein kinase binding Cellular component • plasma membrane • plasma membrane • integrin complex • integral to membrane Biological process • apoptosis • inflammatory response • cell adhesion • leukocyte cell-cell adhesion • cell-matrix adhesion • integrin-mediated signaling pathway • cell-cell signaling • multicellular organismal development • blood coagulation • regulation of cell shape • neutrophil chemotaxis • regulation of peptidyl-tyrosine phosphorylation • regulation of immune response • leukocyte migration Sources: Amigo / QuickGO
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	3689	16414
Ensembl	ENSG00000160255	ENSMUSG00000000290
UniProt	P05107	Q542I8
RefSeq (mRNA)	NM_000211.3	NM_008404.4
RefSeq (protein)	NP_000202.2	NP_032430.2
Location (UCSC)	Chr 21: 46.31 – 46.35 Mb	Chr 10: 76.99 – 77.03 Mb
PubMed search	[1]	[2]

Integrin beta-2 (CD18) is a protein that in humans is encoded by the ITGB2 gene.

It is the beta subunit of four different structures:

• LFA-1 (paired with CD11a)
• Macrophage-1 antigen (paired with CD11b)
• Integrin alphaXbeta2 (paired with CD11c)
• Integrin alphaDbeta2 (paired with CD11d)

The ITGB2 protein product is the integrin beta chain beta 2. Integrins are integral cell-surface proteins composed of an alpha chain and a beta chain. A given chain may combine with multiple partners resulting in different integrins. For example, beta 2 combines with the alpha L chain to form the integrin LFA-1, and combines with the alpha M chain to form the integrin Mac-1. Integrins are known to participate in cell adhesion as well as cell-surface mediated signalling.^[1] In humans lack of CD18 causes Leukocyte Adhesion Deficiency, a disease defined by a lack of leukocyte extravasation from blood into tissues.

Interactions

CD18 has been shown to interact with ICAM-1,^[2][3][4] FHL2,^[5] PSCD1^[6][7] and GNB2L1.^[8]

References

1. ^ "Entrez Gene: ITGB2 integrin, beta 2 (complement component 3 receptor 3 and 4 subunit)". http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=3689. 
2. ^ Kotovuori, A; Pessa-Morikawa T, Kotovuori P, Nortamo P, Gahmberg C G (Jun. 1999). "ICAM-2 and a peptide from its binding domain are efficient activators of leukocyte adhesion and integrin affinity". J. Immunol. (UNITED STATES) 162 (11): 6613–20. ISSN 0022-1767. PMID 10352278. 
3. ^ Lu, C; Takagi J, Springer T A (May. 2001). "Association of the membrane proximal regions of the alpha and beta subunit cytoplasmic domains constrains an integrin in the inactive state". J. Biol. Chem. (United States) 276 (18): 14642–8. doi:10.1074/jbc.M100600200. ISSN 0021-9258. PMID 11279101. 
4. ^ Huang, C; Springer T A (Aug. 1995). "A binding interface on the I domain of lymphocyte function-associated antigen-1 (LFA-1) required for specific interaction with intercellular adhesion molecule 1 (ICAM-1)". J. Biol. Chem. (UNITED STATES) 270 (32): 19008–16. doi:10.1074/jbc.270.32.19008. ISSN 0021-9258. PMID 7642561. 
5. ^ Wixler, V; Geerts D, Laplantine E, Westhoff D, Smyth N, Aumailley M, Sonnenberg A, Paulsson M (Oct. 2000). "The LIM-only protein DRAL/FHL2 binds to the cytoplasmic domain of several alpha and beta integrin chains and is recruited to adhesion complexes". J. Biol. Chem. (UNITED STATES) 275 (43): 33669–78. doi:10.1074/jbc.M002519200. ISSN 0021-9258. PMID 10906324. 
6. ^ Rietzler, M; Bittner M, Kolanus W, Schuster A, Holzmann B (Oct. 1998). "The human WD repeat protein WAIT-1 specifically interacts with the cytoplasmic tails of beta7-integrins". J. Biol. Chem. (UNITED STATES) 273 (42): 27459–66. doi:10.1074/jbc.273.42.27459. ISSN 0021-9258. PMID 9765275. 
7. ^ Geiger, C; Nagel W, Boehm T, van Kooyk Y, Figdor C G, Kremmer E, Hogg N, Zeitlmann L, Dierks H, Weber K S, Kolanus W (Jun. 2000). "Cytohesin-1 regulates beta-2 integrin-mediated adhesion through both ARF-GEF function and interaction with LFA-1". EMBO J. (ENGLAND) 19 (11): 2525–36. doi:10.1093/emboj/19.11.2525. ISSN 0261-4189. PMC 212768. PMID 10835351. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=212768. 
8. ^ Liliental, J; Chang D D (Jan. 1998). "Rack1, a receptor for activated protein kinase C, interacts with integrin beta subunit". J. Biol. Chem. (UNITED STATES) 273 (4): 2379–83. doi:10.1074/jbc.273.4.2379. ISSN 0021-9258. PMID 9442085. 

Further reading

• Bunting M, Harris ES, McIntyre TM, et al. (2002). "Leukocyte adhesion deficiency syndromes: adhesion and tethering defects involving beta 2 integrins and selectin ligands.". Curr. Opin. Hematol. 9 (1): 30–5. doi:10.1097/00062752-200201000-00006. PMID 11753075. 
• Roos D, Law SK (2003). "Hematologically important mutations: leukocyte adhesion deficiency.". Blood Cells Mol. Dis. 27 (6): 1000–4. doi:10.1006/bcmd.2001.0473. PMID 11831866. 
• Gahmberg CG, Fagerholm S (2003). "Activation of leukocyte beta2-integrins.". Vox Sang. 83 Suppl 1: 355–8. PMID 12617168. 
• Schymeinsky J, Mócsai A, Walzog B (2007). "Neutrophil activation via beta2 integrins (CD11/CD18): molecular mechanisms and clinical implications.". Thromb. Haemost. 98 (2): 262–73. PMID 17721605. 

See also

• leukocyte adhesion deficiency
• integrin

External links

• MeSH CD18+antigen
• ITGB2 Info with links in the Cell Migration Gateway