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Protein ITGB2 PDB 1l3y.png
Available structures
PDB Ortholog search: PDBe RCSB
Aliases ITGB2, CD18, LAD, LCAMB, LFA-1, MAC-1, MF17, MFI7, integrin subunit beta 2
External IDs OMIM: 600065 MGI: 96611 HomoloGene: 20092 GeneCards: ITGB2
Gene location (Human)
Chromosome 21 (human)
Chr. Chromosome 21 (human)[1]
Chromosome 21 (human)
Genomic location for ITGB2
Genomic location for ITGB2
Band 21q22.3 Start 44,885,953 bp[1]
End 44,931,989 bp[1]
RNA expression pattern
PBB GE ITGB2 202803 s at fs.png
More reference expression data
Species Human Mouse
RefSeq (mRNA)



RefSeq (protein)



Location (UCSC) Chr 21: 44.89 – 44.93 Mb Chr 21: 77.53 – 77.57 Mb
PubMed search [3] [4]
View/Edit Human View/Edit Mouse

Integrin beta-2 (CD18) is a protein that in humans is encoded by the ITGB2 gene. CD18 plays significant roles in cellular adhesion and cell surface signaling[5].

It is the beta subunit of four different structures:


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.[6]

Clinical significance[edit]

In humans, lack of CD18 causes Leukocyte Adhesion Deficiency, a disease defined by a lack of leukocyte extravasation from blood into tissues. The beta 2 integrins have also been found in a soluble form.[7] The soluble beta 2 integrins are ligand binding and plasma levels are inversely associated with disease activity in the autoimmune disease spondyloarthritis.[8]


CD18 has been shown to interact with:

See also[edit]


  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000160255 - Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000000290 - Ensembl, May 2017
  3. ^ "Human PubMed Reference:". 
  4. ^ "Mouse PubMed Reference:". 
  5. ^ "ITGB2 integrin subunit beta 2 [ Homo sapiens (human) ]". 
  6. ^ "Entrez Gene: ITGB2 integrin, beta 2 (complement component 3 receptor 3 and 4 subunit)". 
  7. ^ Gjelstrup, L. C.; Boesen, T.; Kragstrup, T. W.; Jorgensen, A.; Klein, N. J.; Thiel, S.; Deleuran, B. W.; Vorup-Jensen, T. (8 September 2010). "Shedding of Large Functionally Active CD11/CD18 Integrin Complexes from Leukocyte Membranes during Synovial Inflammation Distinguishes Three Types of Arthritis through Differential Epitope Exposure". The Journal of Immunology. 185 (7): 4154–4168. doi:10.4049/jimmunol.1000952. 
  8. ^ Kragstrup, Tue W; Jalilian, Babak; Hvid, Malene; Kjærgaard, Anders; Østgård, René; Schiøttz-Christensen, Berit; Jurik, Anne G; Robinson, William H; Vorup-Jensen, Thomas; Deleuran, Bent (2014). "Decreased plasma levels of soluble CD18 link leukocyte infiltration with disease activity in spondyloarthritis". Arthritis Research & Therapy. 16 (1): R42. doi:10.1186/ar4471. 
  9. ^ Wixler V, Geerts D, Laplantine E, Westhoff D, Smyth N, Aumailley M, Sonnenberg A, Paulsson M (October 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". The Journal of Biological Chemistry. 275 (43): 33669–78. doi:10.1074/jbc.M002519200. PMID 10906324. 
  10. ^ Liliental J, Chang DD (Jan 1998). "Rack1, a receptor for activated protein kinase C, interacts with integrin beta subunit". The Journal of Biological Chemistry. 273 (4): 2379–83. doi:10.1074/jbc.273.4.2379. PMID 9442085. 
  11. ^ Kotovuori A, Pessa-Morikawa T, Kotovuori P, Nortamo P, Gahmberg CG (June 1999). "ICAM-2 and a peptide from its binding domain are efficient activators of leukocyte adhesion and integrin affinity". Journal of Immunology. 162 (11): 6613–20. PMID 10352278. 
  12. ^ Lu C, Takagi J, Springer TA (May 2001). "Association of the membrane proximal regions of the alpha and beta subunit cytoplasmic domains constrains an integrin in the inactive state". The Journal of Biological Chemistry. 276 (18): 14642–8. doi:10.1074/jbc.M100600200. PMID 11279101. 
  13. ^ Huang C, Springer TA (August 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)". The Journal of Biological Chemistry. 270 (32): 19008–16. doi:10.1074/jbc.270.32.19008. PMID 7642561. 
  14. ^ Rietzler M, Bittner M, Kolanus W, Schuster A, Holzmann B (October 1998). "The human WD repeat protein WAIT-1 specifically interacts with the cytoplasmic tails of beta7-integrins". The Journal of Biological Chemistry. 273 (42): 27459–66. doi:10.1074/jbc.273.42.27459. PMID 9765275. 
  15. ^ Geiger C, Nagel W, Boehm T, van Kooyk Y, Figdor CG, Kremmer E, Hogg N, Zeitlmann L, Dierks H, Weber KS, Kolanus W (June 2000). "Cytohesin-1 regulates beta-2 integrin-mediated adhesion through both ARF-GEF function and interaction with LFA-1". The EMBO Journal. 19 (11): 2525–36. doi:10.1093/emboj/19.11.2525. PMC 212768Freely accessible. PMID 10835351. 

Further reading[edit]

  • Bunting M, Harris ES, McIntyre TM, Prescott SM, Zimmerman GA (Jan 2002). "Leukocyte adhesion deficiency syndromes: adhesion and tethering defects involving beta 2 integrins and selectin ligands". Current Opinion in Hematology. 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, Molecules & Diseases. 27 (6): 1000–4. doi:10.1006/bcmd.2001.0473. PMID 11831866. 
  • Gahmberg CG, Fagerholm S (August 2002). "Activation of leukocyte beta2-integrins". Vox Sanguinis. 83 Suppl 1: 355–8. doi:10.1111/j.1423-0410.2002.tb05333.x. PMID 12617168. 
  • Schymeinsky J, Mócsai A, Walzog B (August 2007). "Neutrophil activation via beta2 integrins (CD11/CD18): molecular mechanisms and clinical implications". Thrombosis and Haemostasis. 98 (2): 262–73. doi:10.1160/th07-02-0156. PMID 17721605. 

External links[edit]