Association of the human CD3-zeta chain with the alpha beta-T cell receptor/CD3 complex. Clues from a T cell variant with a mutated T cell receptor-alpha chain.
The TCR for Ag, on the majority of human T cells, is a disulfide-linked heterodimer composed of TCR-alpha and -beta chains noncovalently associated with the monomorphic CD3 complex composed of the CD3-gamma, -delta, -epsilon, and -zeta chains. The interactions involved in the assembly of the various components of this multimeric protein complex are not fully understood. In this report, a variant of the human leukemic T cell line Jurkat that synthesized all of the known components of the TCR/CD3 complex but fails to express the TCR/CD3 complex at the cell surface is further characterized. This variant, J79, has a mutated TCR-alpha chain that does not affect the assembly of the pentameric form (TCR-alpha beta-CD3-gamma delta epsilon) of the TCR/CD3 complex but inhibits the assembly of the CD3-zeta homodimer with the rest of the complex (TCR-alpha beta-CD3-gamma delta epsilon----TCR-alpha beta-CD3-gamma delta epsilon zeta 2). Transfecting a wild-type TCR-alpha gene into J79 reconstituted expression of a complete functionally competent TCR/CD3 complex at the cell surface. The results indicate that the TCR-alpha chain plays a crucial role in the assembly of the CD3-zeta homodimer with the pentameric form of the TCR/CD3 complex.
Geisler
C
C
Institute for Experimental Immunology, University of Copenhagen, Denmark.
Schøller
J
J
Wahi
M A
MA
Rubin
B
B
Weiss
A
A
D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism*; D017252:CD3 Complex; D002460:Cell Line; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D005434:Flow Cytometry; D006801:Humans; D046911:Macromolecular Substances; D009154:Mutation; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D014162:Transfection
D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D046911:Macromolecular Substances; D011948:Receptors, Antigen, T-Cell