CD18

Integrin ITGAL/ITGB2 is a receptor for ICAM1, ICAM2, ICAM3 and ICAM4. Integrins ITGAM/ITGB2 and ITGAX/ITGB2 are receptors for the iC3b fragment of the third complement component and for fibrinogen. Integrin ITGAX/ITGB2 recognizes the sequence G-P-R in fibrinogen alpha-chain. Integrin ITGAM/ITGB2 recognizes P1 and P2 peptides of fibrinogen gamma chain. Integrin ITGAM/ITGB2 is also a receptor for factor X. Integrin ITGAD/ITGB2 is a receptor for ICAM3 and VCAM1. Contributes to natural killer cell cytotoxicity (By similarity). Involved in leukocyte adhesion and transmigration of leukocytes including T-cells and neutrophils (By similarity). Triggers neutrophil transmigration during lung injury through PTK2B/PYK2-mediated activation.

mCD18

Integrin ITGAL/ITGB2 is a receptor for ICAM1, ICAM2, ICAM3 and ICAM4. Integrin ITGAL/ITGB2 is also a receptor for the secreted form of ubiquitin-like protein ISG15; the interaction is mediated by ITGAL (PubMed:29100055).
Integrins ITGAM/ITGB2 and ITGAX/ITGB2 are receptors for the iC3b fragment of the third complement component and for fibrinogen. Integrin ITGAX/ITGB2 recognizes the sequence G-P-R in fibrinogen alpha-chain. Integrin ITGAM/ITGB2 recognizes P1 and P2 peptides of fibrinogen gamma chain. Integrin ITGAM/ITGB2 is also a receptor for factor X. Integrin ITGAD/ITGB2 is a receptor for ICAM3 and VCAM1. Contributes to natural killer cell cytotoxicity (PubMed:15356110).
Involved in leukocyte adhesion and transmigration of leukocytes including T-cells and neutrophils (PubMed:11812992, PubMed:28807980).
Triggers neutrophil transmigration during lung injury through PTK2B/PYK2-mediated activation (PubMed:18587400).
Integrin ITGAL/ITGB2 in association with ICAM3, contributes to apoptotic neutrophil phagocytosis by macrophages (PubMed:23775590).
In association with alpha subunit ITGAM/CD11b, required for CD177-PRTN3-mediated activation of TNF primed neutrophils (PubMed:21193407).

Aging Source: Ensembl
Amyloid-beta clearance Source: ARUK-UCL
Apoptotic process Source: UniProtKB
Cell adhesion Source: UniProtKB
Cell adhesion mediated by integrin Source: GO_Central
Cell-cell adhesion Source: BHF-UCL
Cell-cell adhesion via plasma-membrane adhesion molecules Source: ARUK-UCL
Cell-cell signaling Source: UniProtKB
Cell-matrix adhesion Source: UniProtKB
Cell migration Source: GO_Central
Cellular extravasation Source: Ensembl
Cellular response to low-density lipoprotein particle stimulus Source: UniProtKB
Cytokine-mediated signaling pathway Source: Reactome
Endodermal cell differentiation Source: UniProtKB
Endothelial cell migration Source: Ensembl
Extracellular matrix organization Source: Reactome
Heterotypic cell-cell adhesion Source: UniProtKB
Inflammatory response Source: UniProtKB
Integrin-mediated signaling pathway Source: UniProtKB
Leukocyte cell-cell adhesion Source: UniProtKB
Leukocyte migration Source: Reactome
Leukocyte migration involved in inflammatory response Source: Ensembl
Microglial cell activation Source: ARUK-UCL
Natural killer cell activation Source: Ensembl
Negative regulation of dopamine metabolic process Source: ARUK-UCL
Neutrophil chemotaxis Source: UniProtKB
Neutrophil degranulation Source: Reactome
Neutrophil migration Source: UniProtKB
Phagocytosis, engulfment Source: ARUK-UCL
Positive regulation of angiogenesis Source: Ensembl
Positive regulation of leukocyte adhesion to vascular endothelial cell Source: UniProtKB
Positive regulation of neuron death Source: ARUK-UCL
Positive regulation of neutrophil degranulation Source: UniProtKB
Positive regulation of NF-kappaB transcription factor activity Source: Ensembl
Positive regulation of nitric oxide biosynthetic process Source: Ensembl
Positive regulation of prostaglandin-E synthase activity Source: ARUK-UCL
Positive regulation of protein targeting to membrane Source: ARUK-UCL
Positive regulation of superoxide anion generation Source: UniProtKB
Receptor clustering Source: UniProtKB
Receptor internalization Source: UniProtKB
Receptor-mediated endocytosis Source: ARUK-UCL
Regulation of cell shape Source: UniProtKB
Regulation of immune response Source: Reactome
Regulation of peptidyl-tyrosine phosphorylation Source: UniProtKB
Toll-like receptor 4 signaling pathway Source: Reactome

Cell membrane; Membrane raft

Leukocyte adhesion deficiency 1 (LAD1): LAD1 patients have recurrent bacterial infections and their leukocytes are deficient in a wide range of adhesion-dependent functions.

Extracellular: 23-700
Helical: 701-723
Cytoplasmic: 724-769

Both Ser-745 and Ser-756 become phosphorylated when T-cells are exposed to phorbol esters (PubMed:11700305). Phosphorylation on Thr-758 (but not on Ser-756) allows interaction with 14-3-3 proteins (PubMed:11700305, PubMed:16301335).