CD3D-CD3E Heterodimer Protein, Mouse (HEK293, Flag-His)

The CD3D protein is a crucial component of the TCR-CD3 complex found on the surface of T-lymphocytes, playing a pivotal role in adaptive immune responses. Upon activation of the T-cell receptor (TCR) by antigen-presenting cells (APCs), CD3D, along with CD3E, CD3G, and CD3Z, transmits TCR-mediated signals across the cell membrane. These CD3 chains contain immunoreceptor tyrosine-based activation motifs (ITAMs) in their cytoplasmic domain, which, upon phosphorylation by LCK and FYN kinases, activate downstream signaling pathways. Beyond its role in signal transduction for T-cell activation, CD3D is indispensable in thymocyte differentiation, contributing to proper intracellular TCR-CD3 complex assembly and surface expression. Dysfunction in the TCR-CD3 complex leads to impaired thymocyte differentiation. CD3D further interacts with CD4 and CD8, establishing a functional link between the TCR and coreceptors CD4 and CD8, crucial for the activation and positive selection of CD4 or CD8 T-cells. The TCR-CD3 complex consists of CD3D/CD3E and CD3G/CD3E heterodimers, forming trimers that associate with TCRalpha and TCRbeta. Additionally, the hexamer interacts with CD3Z homodimer to complete the TCR-CD3 complex, wherein TCRalpha and TCRbeta can be replaced by TCRgamma and TCRdelta. This intricate interaction network highlights the multifaceted role of CD3D in orchestrating T-cell responses.