| CD100 | SEMA4D (semaphorin-4D) |
| Molecule Type | Antigen Expression | Molecular Weight Min / Max |
| Non-lineage Restricted Molecule Type 1 glycoprotein | Myeloid Cell Hematopoietic Cell T Cell B Cell Nonhematopoietic Cell Germinal Center Kidney Brain Heart T Lymphocyte | 120 / 120 150 / 150 300 / 300 |
Expression | ||||||||||||||||||||
| CD100 is expressed on most hematopoietic cells with the exception of immature bone marrow cells, red blood cells, platelets, erythrocytes, eosinophils, endothelial cells or K562 cells. Expression is strong on resting T cells. Expression is weak on resting B cells and antigen presenting cells but is upregulated upon activation. CD100 is expressed on most non-hematopoietic tissues including the embryonic and adult brain, heart, and kidney. Expression occurs on myeloid cells and is expressed on T lymphocytes and is associated with protein tyrosine phosphatase CD45 on T and B cells. Expression is on germinal center B cells but not on mantle zone B cells. | ||||||||||||||||||||
Structure | ||||||||||||||||||||
| MOLECULAR FAMILY NAME: Belongs to the semaphorin family. CD100 is a disulfide-linked homodimeric single-pass type-1 863-aa glycoprotein. It contains a secretory signal sequence, an extracellular domain which contains an Ig-like C2-type domain, a 500-aa N-terminal sema domain, a 104-aa lysine-rich stalk, potential N-linked glycosylation sites, and a hydrophobic transmembrane domain. CD100 also contains a 110-aa C-terminal cytoplasmic domain which has no catalytic domains but has consensus sites for tyrosine and serine phosphorylation. Soluble CD100 is generated from the transmembrane domain via a proteolytic cascade initiated after activation of primary T and B cells. It belongs to the subclass IV semaphorin (sema) superfamily within the Ig gene superfamily and is the only semaphorin member known to be expressed physiologically in the immune system. MOLECULAR MASS
POST-TRANSCRIPTIONAL MODIFICATION: No information. POST-TRANSLATIONAL MODIFICATION: No information. | ||||||||||||||||||||
Ligands | ||||||||||||||||||||
| CD100 binds CD72 in the immune system and displays high affinity binding to plexin-B1 and plexin-B2 (PLXNB1 and PLXNB2) in non-hematopoietic tissues. Interaction with these plexin proteins is thought to play an important role in cell-cell signaling. LIGANDS AND MOLECULES ASSOCIATED WITH CD100
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Function | ||||||||||||||||||||
| CD100 functions in monocyte migration, T and B cell activation, and T/ B cell and T/dendritic cell interaction. CD100 is thought to play a role in lymphocyte activation. CD100 expresses transfectants. The transfection of cells with CD100 or soluble CD100 promotes B cell activation by inducing homotypic adhesion of B cells, downregulating expression of CD23, and modifying CD40-CD40L B cell signaling. CD100 binds to CD72 establishing a semaphorin-receptor binding pair in the immune system, and may exert its positive effects on B cells by the binding and damping CD72-negative signaling. CD72 is constitutively tyrosine phosphorylated and associated with SHP-1; B cells are hyporesponsive in CD100-deficient mice. Antibody crosslinking of CD100 on T cells increases both CD2- and CD3-induced T cell proliferation. The identification of CD100 as a semaphorin suggests a possible role in neuronal guidance. CD100 increases PMA-, CD3- and CD2-induced T cell proliferation, increases CD45-induced T cell adhesion, and induces B cell homotypic adhesion. CD100 mediates axon repulsion via its receptor plexin-B1 and may help guide developing neuronal cells; CD100 is thought to promote reorganization of the actin cytoskeleton and guide axonal growth cones in the developing nervous system. In epithelial cells, the binding of CD100 to plexin-B1/Met (scatter factor-1) complex induces phosphorylation of the complex that is crucial for epithelial cell invasive growth. Recombinant soluble CD100 has been shown to induce proinflammatory cytokine release by monocytes and inhibit spontaneous and MCP-3 induced migration of monocytes or a monocytic cell line. BIOCHEMICAL ACTIVITY CD100 is associated with PTPase and serine kinase activity. DISEASE RELEVANCE AND FUNCTION OF CD100 IN INTACT ANIMAL CD100 may play a functional role in the immune system as in the nervous system. | ||||||||||||||||||||
Comments | ||||||||||||||||||||
| MOLECULAR INTERACTIONS - PROTEINS AND DNA ELEMENTS WHICH REGULATE TRANSCRIPTION OF CD100: No information. SUBSTRATES: No information. ENZYMES WHICH MODIFY CD100: No information. To learn more about CD100, see the Genecards database at the following link: SEMA4D Gene, SEMA4D Protein, SEMA4D Antibody | Genecards | ||||||||||||||||||||
Database accession numbers | ||||||||||||||||||||
Revised June 25, 2008
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