Premium
Masking of the CD3γ di‐Leucine‐based Motif by ζ is Required for Efficient T‐Cell Receptor Expression
Author(s) -
Lauritsen Jens Peter H.,
Bonefeld Charlotte Menné,
von Essen Marina,
Nielsen Martin Weiss,
Rasmussen Anette Bødker,
Ødum Niels,
Dietrich Jes,
Geisler Carsten
Publication year - 2004
Publication title -
traffic
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.677
H-Index - 130
eISSN - 1600-0854
pISSN - 1398-9219
DOI - 10.1111/j.1600-0854.2004.00211.x
Subject(s) - t cell receptor , biology , cd3 , endocytosis , microbiology and biotechnology , t cell , endocytic cycle , receptor , cd8 , biochemistry , antigen , immune system , immunology
The T‐cell receptor (TCR) is a multimeric receptor composed of the Tiαβ heterodimer and the noncovalently associated CD3γδε and ζ 2 chains. All of the TCR chains are required for efficient cell surface expression of the TCR. Previous studies on chimeric molecules containing the di‐leucine‐based endocytosis motif of the TCR subunit CD3γ have indicated that the ζ chain can mask this motif. In this study, we show that successive truncations of the cytoplasmic tail of ζ led to reduced surface expression levels of completely assembled TCR complexes. The reduced TCR expression levels were caused by an increase in the TCR endocytic rate constant in combination with an unaffected exocytic rate constant. Furthermore, the TCR degradation rate constant was increased in cells with truncated ζ. Introduction of a CD3γ chain with a disrupted di‐leucine‐based endocytosis motif partially restored TCR expression in cells with truncated ζ chains, indicating that the ζ chain masks the endocytosis motif in CD3γ and thereby stabilizes TCR cell surface expression.