Human T-Cell Surface Glycoprotein CD3 Gamma Chain (CD3G) Protein

Background

CD3G, the gamma subunit of the T-cell receptor (TCR) complex, is a crucial component of the TCR-CD3 complex, which plays an essential role in T-cell activation, signal transduction, and immune responses. The TCR-CD3 complex is responsible for recognizing antigens bound to major histocompatibility complex (MHC) molecules on antigen-presenting cells (APCs). This recognition initiates signaling cascades that activate T cells, leading to immune responses such as T-cell proliferation, cytokine production, and differentiation into effector cells. The CD3 complex consists of multiple subunits, including CD3G (gamma), CD3E (epsilon), CD3D (delta), and CD3Z (zeta), which associate with the TCR α/β or γ/δ heterodimers to form the full TCR-CD3 complex. The CD3G gene is located on chromosome 11q23, adjacent to the CD3D gene. It encodes the CD3γ chain, a transmembrane protein that is integral to the structural stability and function of the TCR-CD3 complex. CD3G is expressed on the surface of all mature T lymphocytes and certain natural killer (NK) cells, where it contributes to immune surveillance, host defense against infections, and recognition of transformed cells (e.g., tumor cells).