Assembly, intracellular processing, and expression at the cell surface of the human alpha beta T cell receptor/CD3 complex. Function of the CD3-zeta chain.
The TCR/CD3 complex is a multimeric protein complex composed of a minimum of seven transmembrane chains (TCR alpha beta-CD3 gamma delta epsilon zeta 2). Whereas earlier studies have demonstrated that both the TCR-alpha and -beta chains are required for the cell surface expression of the TCR/CD3 complex, the role of the CD3 chains for the TCR/CD3 expression have not been experimentally addressed in human T cells. In this study the function of the CD3-zeta chain for the assembly, intracellular processing, and expression of the TCR/CD3 complex in the human leukemic T cell line Jurkat was investigated. The results indicate that: 1) CD3-zeta is required for the cell surface expression of the TCR/CD3 complex; 2) the pentameric form (TCR alpha beta-CD3 gamma delta epsilon) of the TCR/CD3 complex and single TCR chains associated with CD3 (TCR alpha-CD3 gamma delta epsilon and TCR beta-CD3 gamma delta epsilon) are produced in the endoplasmic reticulum in the absence of CD3-zeta; 3) the CD3-zeta does not associate with TCR alpha-CD3 gamma delta epsilon or TCR beta-CD3 gamma delta epsilon complexes; 4) CD3-zeta associate with the pentameric form of the TCR/CD3 complex in the endoplasmic reticulum to form the heptameric complex (TCR alpha beta-CD3 gamma delta epsilon----TCR alpha beta-CD3 gamma delta epsilon 2); and 5) CD3-zeta is required for the export of the TCR/CD3 complex from the endoplasmic reticulum to the Golgi apparatus for subsequent processing.
Geisler
C
C
Tissue Typing Laboratory, State University Hospital, Copenhagen, Denmark.
Kuhlmann
J
J
Rubin
B
B
D000945:Antigens, Differentiation, T-Lymphocyte / Q000302:isolation & purification / Q000378:metabolism* / Q000502:physiology; D015152:Blotting, Northern; D017252:CD3 Complex; D002460:Cell Line; D002999:Clone Cells / Q000032:analysis / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005434:Flow Cytometry; D006056:Golgi Apparatus / Q000378:metabolism; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D008565:Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000302:isolation & purification / Q000378:metabolism* / Q000502:physiology; D013601:T-Lymphocytes / Q000032:analysis / Q000378:metabolism
D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D007376:Interleukin-2; D008565:Membrane Proteins; D011948:Receptors, Antigen, T-Cell