CD167b DDR2 (discoidin domain receptor family, member 2)
Molecule TypeAntigen ExpressionMolecular Weight
Min / Max
Non-lineage Restricted Molecule
Type 1 glycoprotein
Heart
Lung
Skin
Kidney
Skeletal muscle
130 / 130

Expression
CD167b is widely expressed but has high expression in skeletal and heart muscle, kidney,
skin and lung, and at less levels in brain, placenta, liver and pancreas.

Structure
MOLECULAR FAMILY NAME: Belongs to the tyrosine kinase family.

CD167b is a single-pass type-1 855 aa glycoprotein.  It is a tripartite structure which contains an 155 aa discoidin extracellular domain followed by a 200 aa stalk and contains a F5/8 type C domain and a VIII-like domain, a transmembrane domain and cytoplasmic domain which has a juxtamembrane region and a catalytic tyrosine region.  CD167b belongs to a subfamily of tyrosine kinase receptors with a homology region to the Dictyostelium discoideum protein discoidin I in their extracellular domain.  There are 2 members that have been identified as CD167a (DDR1) and CD167b ( DDR2).  During the cell aggregation of Dictyostelium, the related molecule is secreted and functions as a lectin.  It is thought to be important in the maintenance of morphology, cytoskeletal organization, and the ability to align with other cells during aggregation.  The discoidin domain in the extracellular regions, CD167a and CD167b, are thought to play a role in cell-cell contact and in cell adhesion signaling pathways.  In both CD167a and b, ligand binding is thought to trigger receptor dimerization, which would enable transphosphorylation of tyrosine residues.

Discoidin domains, also called Factor VIII-homology or DS domains, are found in a variety of other proteins.  Transmembrane proteins with the discoidin domain are CD167b, neurexin, and neuropilin, A5 antigen in Xenopus.  Secreted proteins with the discoidin domain are blood clotting factor 5, blood clotting factor 8, AEBP1, MFG-E8, BA46, Del-1, and XLRS-1.  The kinase domain has high homology to mammalian TrkA, B and C, and to the marine sponge tyrosine kinase receptor GCTK from Geodia cydonium.

MOLECULAR MASS

POST-TRANSCRIPTIONAL MODIFICATION: No information.

POST-TRANSLATIONAL MODIFICATION: No information.

Ligands
LIGANDS AND MOLECULES ASSOCIATED WITH CD167b

CD167b binds fibrillar collagens type-1-3 and 5.

Function

Receptor tyrosine kinases (RTKs) play a role in the communication of cells with their microenvironment.  CD167b is a tyrosine kinase activated by triple helical fibrillar glycosylated collagen.  When activated CD167b induces the expression of MMP1 and MMP2.  It is involved in the regulation of cell proliferation and ECM remodeling mediated by metalloprotease MMP1 (collagenase 1) and MMP2 (gelatinase A).  These molecules are involved in the regulation of cell growth, differentiation and metabolism.  The biomedical mechanism by which RTKs transduce signals across the membrane has been shown to be a ligand induced receptor oligomerization and subsequent intracellular phosphorylation.  This autophosphorylation leads to phosphorylation of cytosolic targets as well as association with other molecules, which are involved in pleiotropic effects of signal transduction.  CD167b functions as an adhesion molecule and is a collagen recept that mediates fibroblast migration and proliferation.  Various types of collagen have been identified as the cognate ligands for both DDR's.  CD167a and CD167b autophosphorylation is achieved by all collagens tested, type 1-type 6.  CD167b is only activated by fibrillar collagens especially type 1 and 3. 

BIOCHEMICAL ACTIVITY: No information.

DISEASE RELEVANCE AND FUNCTION OF CD167b IN INTACT ANIMAL

CD167b contributes to cutaneous wound healing.  CD167b knockout mice are smaller than wild type and have delayed healing of epidermal wounds.



Comments
MOLECULAR INTERACTION-
PROTEINS AND DNA ELEMENTS WHICH REGULATE TRANSCRIPTION OF CD167b: No information.

SUBSTRATES: No information.

ENZYMES WHICH  MODIFY CD167b: No information.

Database accession numbers
AnimalPIRSWISSPROTEMGBL/GENBANK
 
HumanEntrezgene 4921Q16832
Antibodies

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