Molecular Classification
Receptor subunit, Transmembrane protein
Other Names
T-cell surface glycoprotein CD3 zeta chain, T-cell receptor T3 zeta chain, CD247, TCR-T3 zeta chain, Cluster of Differentiation 247
Disease Roles
ImmunodeficiencyAutoimmune diseasesCancer (T-cell lymphomas)

CD3 zeta chain Overview

The CD3 zeta chain (CD247) is a crucial transmembrane subunit of the T-cell receptor (TCR)-CD3 complex. It plays a critical role in adaptive immune responses by transmitting signals from antigen recognition to intracellular signaling pathways via its immunoreceptor tyrosine-based activation motifs (ITAMs). The ζζ homodimer provides six ITAMs to the complex, making it central to downstream signaling. Low expression or absence impairs immune responses. It interacts with JAK3, protein unc119 homolog, and other proteins involved in immunological synapse formation. Microbial proteins such as HIV Nef can modulate these interactions, affecting immune function. It is expressed predominantly in lymphoid tissues and peripheral blood mononuclear cells.

Mechanism of Action

Not applicable (subunit of a receptor complex; direct targeting is rare)

Biological Functions

Signal transduction
Immune response
T-cell activation
T-cell proliferation
Cytokine production

Disease Associations

Immunodeficiency
Autoimmune diseases
Cancer (T-cell lymphomas)
Infection

Safety Considerations

  • Immunosuppression
  • Increased risk of infection
  • Autoimmunity (potential for off-target effects if directly targeted)

Associated Biomarkers

Biomarker
CD3 zeta chain expression levels in T cells
Phosphorylation status of ITAM motifs