Rapid turnover of the CD3 zeta chain independent of the TCR-CD3 complex in normal T cells.

The function of CD3 zeta in the assembly and transport of the T cell receptor (TCR)-CD3 complex was analyzed in normal T cells. The zeta chain, but not other chains in the surface TCR complex, rapidly exchanged with newly synthesized zeta. Because zeta was expressed independently from the complex, the TCR complex may be transported to the surface along the zeta turnover pathway by association with zeta. These data suggest the dynamic nature of zeta metabolism and provide the evidence that a single component in a multisubunit receptor exhibits independent metabolism from the rest of the complex.