CD3D

CD3D (CD3d Molecule) is a Protein Coding gene. Diseases associated with CD3D include Immunodeficiency 19 and T-B+ Severe Combined Immunodeficiency Due To Cd3delta/Cd3epsilon/Cd3zeta. Among its related pathways are G-protein signaling N-RAS regulation pathway and Toll-like receptor signaling pathway. Gene Ontology (GO) annotations related to this gene include protein heterodimerization activity and transmembrane signaling receptor activity. An important paralog of this gene is CD3G.

CD3d Molecule

Part of the TCR-CD3 complex present on T-lymphocyte cell surface that plays an essential role in adaptive immune response. When antigen presenting cells (APCs) activate T-cell receptor (TCR), TCR-mediated signals are transmitted across the cell membrane by the CD3 chains CD3D, CD3E, CD3G and CD3Z. All CD3 chains contain immunoreceptor tyrosine-based activation motifs (ITAMs) in their cytoplasmic domain. Upon TCR engagement, these motifs become phosphorylated by Src family protein tyrosine kinases LCK and FYN, resulting in the activation of downstream signaling pathways (PubMed:2470098).

In addition of this role of signal transduction in T-cell activation, CD3D plays an essential role in thymocyte differentiation. Indeed, participates in correct intracellular TCR-CD3 complex assembly and surface expression. In absence of a functional TCR-CD3 complex, thymocytes are unable to differentiate properly. Interacts with CD4 and CD8 and thus serves to establish a functional link between the TCR and coreceptors CD4 and CD8, which is needed for activation and positive selection of CD4 or CD8 T-cells(PubMed:12215456).

Adaptive immune response Source: UniProtKB-KW
Cell surface receptor signaling pathway Source: GO_Central
Membrane organization Source: Reactome
Positive thymic T cell selection Source: UniProtKB
Regulation of immune response Source: Reactome
T cell receptor signaling pathway Source: Reactome

Cell membrane

Immunodeficiency 19 (IMD19): An autosomal recessive form of severe combined immunodeficiency characterized by onset in early infancy of recurrent bacterial, viral, and fungal infections. Patients usually have chronic diarrhea, recurrent respiratory infections, and failure to thrive. Immunologic work-up shows a T-cell negative, B-cell positive, NK-cell positive phenotype.

Extracellular: 22-105
Helical: 106-126
Cytoplasmic: 127-171

Phosphorylated on Tyr residues after T-cell receptor triggering by LCK in association with CD4/CD8.