|CD88||C5a-R, C5R1 (complement component 5a receptor 1)|
|Molecule Type||Antigen Expression||Molecular Weight|
Min / Max
|Non-lineage Restricted Molecule|
Type 3 glycoprotein, 7 span
|43 / 43|
|CD88 is expressed on granulocytes, monocytes, dendritic cells, the hepatoma-derived cell line HepG2, astrocytes and microglia. It is also expressed on hepatocytes and on many cell types in the lung, including bronchial and alveolar epithelial cells, alveolar macrophages and vascular endothelial cells. CD88 mRNA has also been detected in the heart, spleen, kidney and intestine but the cell types expressing CD88 have not been identified. C5a is expressed on human neutrophils. Receptors for the chemoattractants C5a and IL-8 are clustered on the surface of human neutrophils.|
|MOLECULAR FAMILY NAME: Belongs to the rhodopsin superfamily.|
CD88 is a multi-pass type-3, 7 span 350 aa glycoprotein. It is a typical G protein-coupled receptor which contains 7 hydrophobic transmembrane-spanning domains. CD88 is related to the CD128 molecule and the N-fomyl peptide receptor.
POST-TRANSCRIPTIONAL MODIFICATION:No information.
CD88 is glycosylated and is phosphorylated in response to C5a or after stimulation of cells with phorbol esters.
|CD88 binds anaphylatoxin and C5a/5a (des Arg) which is the N-terminal fragment with 74 residues in the human of the a chain of the complement component C5. This fragment is proteolytically cleaved from C5 during complement activation. CD88 is coupled to heterotrimeric G proteins inside the cell. In neutrophils, CD88 appears to couple exclusively to the G proteins Gia2 and Gia3, which are pertussis toxin sensitive.|
LIGANDS AND MOLECULES ASSOCIATED WITH CD88
|CD88 is a G-protein-coupled receptor involved in C5a-mediated inflammation and activation of granulocytes. The CD88 residue Asp-282 near the extracellular face of the transmembrane domain VII, is a component of the ligand-binding site responsible for C5 receptor activation. The binding of C5a to CD88 on neutrophils leads to a number of effects including with increasing C5a concentrations, cytoskeletal remodeling, shedding of selectins, upregulation of adhesion molecules, chemotaxis, granule exocytosis and activation of NADPH oxidase. |
The C5a occupied receptor stimulates the GTPase activity of Gi2.
DISEASE RELEVANCE AND FUNCTION OF CD88 IN INTACT ANIMAL
A role in mucosal defense to infection is indicated by the failure of CD88 knockout mice to clear Pseudomonas aeruginosa introduced directly into the trachea. Neutrophil migration into the lung is elevated while migration into the peritoneum in response to glycogen-induced inflammation is decreased. It is thought that CD88 may have a therapeutic role in antiphospholipid syndrome, a recurring pregnancy loss and thrombosis disease.
|MOLECULAR INTERACTIONS -|
PROTEINS AND DNA ELEMENTS WHICH REGULATE TRANSCRIPTION OF CD88: No information.
SUBSTRATES: No information.
ENZYMES WHICH MODIFY CD88: No information.
Database accession numbers
Revised June 25, 2008