The Full Wiki

More info on CD3 (immunology)

CD3 (immunology): Wikis


Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! This article doesn't yet, but we're working on it! See more info or our list of citable articles.


From Wikipedia, the free encyclopedia

The T-cell receptor complex with TCR-α and TCR-β chains, CD3 and ζ-chain accessory molecules and the co-receptor CD4
CD3d molecule, delta (CD3-TCR complex)
Symbol CD3D
Alt. symbols T3D
Entrez 915
HUGO 1673
OMIM 186790
RefSeq NM_000732
UniProt P04234
Other data
Locus Chr. 11 q23
CD3e molecule, epsilon (CD3-TCR complex)
Symbol CD3E
Entrez 916
HUGO 1674
OMIM 186830
RefSeq NM_000733
UniProt P07766
Other data
Locus Chr. 11 q23
CD3g molecule, gamma (CD3-TCR complex)
Symbol CD3G
Entrez 917
HUGO 1675
OMIM 186740
RefSeq NM_000073
UniProt P09693
Other data
Locus Chr. 11 q23

In immunology, the CD3 T-Cell Co-Receptor (CD stands for cluster 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 the T cell receptor (TCR) and the ζ-chain to generate an activation signal in T 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 single extracellular immunoglobulin domain.

The transmembrane region of the CD3 chains is positively charged, a characteristic that allows these chains to associate with the negatively charged TCR chains (it contains aspartat residues in the transmembrane region)[1] (TCRα and TCRβ).

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 an enzyme called ZAP70 (zeta associated protein), a kinase that is important in the signaling cascade of the T cell.


  1. ^ KINDT, T, et al., Immunologie générale, le cours de Janis Kuby avec questions de révision, 2008, 6ème édition, Paris, Éditions Dunod, p.236, 683 pages
  • Cellular and Molecular Immunology (5th Ed.) Abbas AK, and Lichtman, Editor: Saunders, Philadelphia, 2003.

External links



Got something to say? Make a comment.
Your name
Your email address