- CD3 (immunology)
protein
Name = CD3d molecule, delta (CD3-TCR complex)
caption =
width = 180px
HGNCid = 1673
Symbol =CD3D
AltSymbols = T3D
EntrezGene = 915
OMIM = 186790
RefSeq = NM_000732
UniProt = P04234
PDB = 1XIW
ECnumber =
Chromosome = 11
Arm = q
Band = 23
LocusSupplementaryData = protein
Name = CD3e molecule, epsilon (CD3-TCR complex)
caption =
width = 180px
HGNCid = 1674
Symbol =CD3E
AltSymbols =
EntrezGene = 916
OMIM = 186830
RefSeq = NM_000733
UniProt = P07766
PDB =
ECnumber =
Chromosome = 11
Arm = q
Band = 23
LocusSupplementaryData = protein
Name = CD3g molecule, gamma (CD3-TCR complex)
caption =
width = 180px
HGNCid = 1675
Symbol =CD3G
AltSymbols =
EntrezGene = 917
OMIM = 186740
RefSeq = NM_000073
UniProt = P09693
PDB =
ECnumber =
Chromosome = 11
Arm = q
Band = 23
LocusSupplementaryData =In
immunology , the CD3antigen (CD stands forcluster of differentiation ) is a protein complex and is composed of four distinct chains. In mammals, the complex contains a CD3γ chain, a CD3δ chain, and two CD3ε chains. These chains associate with a molecule known as theT cell receptor (TCR) and theζ-chain to generate an activation signal inT lymphocytes .The TCR, ζ-chain and CD3 molecules together comprise the TCR complex.
The CD3γ, CD3δ, and CD3ε chains are highly related cell surface proteins of the
immunoglobulin superfamily containing a singleextracellular immunoglobulin domain.The transmembrane region of the CD3 chains is negatively charged, a characteristic that allows these chains to associate with the positively charged TCR chains (
TCRα andTCRβ ).The intracellular tails of the CD3 molecules contain a single conserved motif known as an "
immunoreceptor tyrosine-based activation motif " or ITAM for short, which is essential for the signaling capacity of the TCR.Phosphorylation of the ITAM on CD3 renders the CD3 chain capable of binding anenzyme calledZAP70 (zeta associated protein), akinase that is important in the signaling cascade of the T cell.References
* Cellular and Molecular Immunology (5th Ed.) Abbas AK, and Lichtman, Editor: Saunders, Philadelphia, 2003.
External links
*
Wikimedia Foundation. 2010.