CD84 GR6, p75, SLAMF5, Hly9-β
Molecule TypeAntigen ExpressionMolecular Weight
Min / Max
Non-lineage Restricted Molecule
Type 1 glycoprotein
T Cell
Thymocyte
Hematopoietic Cell
Monocyte
Macrophage
B Cell
NK Cell
64 / 64
82 / 82

Expression
CD84 is expressed on virtually all thymocytes.  CD4- and CD8- immature thymocytes express the highest levels of CD84.  Expression in human and mouse is restricted to hematopoietic tissues and cells.  It is expressed at high levels on B cells, NK cells, CD45R0+ T cells and monocytes and at low levels on other cells such as granulocytes, platelets, polymorphs and T cells.  It is highly expressed on tissue macrophages but is not expressed on plasma cells.



Structure
MOLECULAR FAMILY NAME:  Belongs to the immunoglobulin supergene family.

CD84 is a single-pass type 1 glycoprotein.  It contains a 21 signal sequence, an 189 aa extracellular domain which contains an Ig-like V-type NH-2 terminal domain that lacks the disulphide bond between the β sheets, an Ig-like C2-type domain with 2 putatuve disulphide bonds and has 4 N-linked and 29 O linked glycosylation sites, a 25 aa hydrophic transmembrane region and a 83 aa cytoplasmic domain containing 5 tyrosines and Src homology 2 (SH2) domain binding motifs (TxYxxV/I) common to the cytoplasmic domains of CD2 family members.  The extracellular Ig-like domains show structural and sequence homology with a group of members of the Ig superfamily that include CD2, CD48, CD58, CD150 (SLAM), 2B4 and Ly-9.  The members of this family have shown to act as adhesion and co-stimulatory molecules. 

MOLECULAR MASS OF CD84
Cell Type Unreduced Reduced Comment
Unspecified 68-80 kDa 72-86 kDa

POST-TRANSCRIPTIONAL MODIFICATION

Alternative splicing yields 7 different isoforms.

POST-TRANSLATIONAL MODIFICATION

CD84 is highly N-glycosylated and has 4 potential N-linked glycosylation sites and 29 O-linked glycosylatiuon sites in the extracellular domain.

Ligands
LIGANDS AND MOLECULES ASSOCIATED WITH CD84: No information.



Function
The CD84 function is unknown but the structural similarties to other adhesion molecules such as CD2 and CD48 suggest a function of intracellular interaction and signaling.  CD84 functions as a homotypic adhesion molecule and as a lymphocytic costimulatory molecule.  Ligation of CD84 by mAb enchances proliferation of anti-CD3 mAb stimulated human T cells and enhances IFN-γ secretion by lymphocytes.  CD84 associates with cytoplasmic, SH2 domain-containing peptides SAP and EAT-2.  The cytoplasmic tail contains 2 tyrosine based motifs also found in the cytoplasmic domain of CD150 (SLAM), CD244 (2B4) and CD229 (Ly-9).  This motif is critical for binding CD150 and CD244 to a protein SLAM-associated protein (SAP) or SH2D1a that is mutated in the immunodeficiency X-linked lymphoproliferative syndrome.  It has been proposed that impaired signaling via this receptor is responsible for immunodeficiency. 

BIOCHEMICAL ACTIVITY: No information.

DISEASE RELEVANCE AND FUNCTION OF CD84 IN INTACT ANIMAL: No information.

Comments
MOLECULAR INTERACTIONS -
PROTEINS AND DNA ELEMENTS WHICH REGULATE TRANSCRIPTION OF CD84: No information.

SUBSTRATES: No information.

ENZYMES WHICH MODIFY CD84: No information.

ADDITIONAL INSIGHTS

Treatment of CD84 causes phosphorylation of tryosine residues.  Indications suggest that the tyrosine phosphatase SHP-2 binds to cytoplasmic tail.


Database accession numbers
AnimalPIRSWISSPROTEMGBL/GENBANK
 
HumanEntrezgene 8832Q9UIB8
Antibodies
2G7   View Reactivity

Revised June 25, 2008


Contact us: Webmaster |  509-335-9515 | Accessibility | Copyright | Policies
College of Veterinary Medicine Washington State University, Pullman, WA, 99164-7010 USA
Copyright 1995-2003 Washington State University