TY - JOUR
T1 - The CD3 ζ subunit contains a phosphoinositide-binding motif that is required for the stable accumulation of TCR-CD3 complex at the immunological synapse
AU - DeFord-Watts, Laura M.
AU - Dougall, David S.
AU - Belkaya, Serkan
AU - Johnson, Blake A.
AU - Eitson, Jennifer L.
AU - Roybal, Kole T.
AU - Barylko, Barbara
AU - Albanesi, Joseph P.
AU - Wülfing, Christoph
AU - Van Oers, Nicolai S C
PY - 2011/6/15
Y1 - 2011/6/15
N2 - T cell activation involves a cascade of TCR-mediated signals that are regulated by three distinct intracellular signaling motifs located within the cytoplasmic tails of the CD3 chains. Whereas all the CD3 subunits possess at least one ITAM, the CD3 ε subunit also contains a proline-rich sequence and a basic-rich stretch (BRS). The CD3 ε BRS complexes selected phosphoinositides, interactions that are required for normal cell surface expression of the TCR. The cytoplasmic domain of CD3 ζ also contains several clusters of arginine and lysine residues. In this study, we report that these basic amino acids enable CD3 ζ to complex the phosphoinositides PtdIns(3)P, PtdIns(4)P, PtdIns(5)P, PtdIns(3,5)P2, and PtdIns(3,4,5)P3 with high affinity. Early TCR signaling pathways were unaffected by the targeted loss of the phosphoinositide-binding functions of CD3 ζ. Instead, the elimination of the phosphoinositide-binding function of CD3 ζ significantly impaired the ability of this invariant chain to accumulate stably at the immunological synapse during T cell-APC interactions. Without its phosphoinositide-binding functions, CD3 ζ was concentrated in intracellular structures after T cell activation. Such findings demonstrate a novel functional role for CD3 ζ BRS-phosphoinositide interactions in supporting T cell activation.
AB - T cell activation involves a cascade of TCR-mediated signals that are regulated by three distinct intracellular signaling motifs located within the cytoplasmic tails of the CD3 chains. Whereas all the CD3 subunits possess at least one ITAM, the CD3 ε subunit also contains a proline-rich sequence and a basic-rich stretch (BRS). The CD3 ε BRS complexes selected phosphoinositides, interactions that are required for normal cell surface expression of the TCR. The cytoplasmic domain of CD3 ζ also contains several clusters of arginine and lysine residues. In this study, we report that these basic amino acids enable CD3 ζ to complex the phosphoinositides PtdIns(3)P, PtdIns(4)P, PtdIns(5)P, PtdIns(3,5)P2, and PtdIns(3,4,5)P3 with high affinity. Early TCR signaling pathways were unaffected by the targeted loss of the phosphoinositide-binding functions of CD3 ζ. Instead, the elimination of the phosphoinositide-binding function of CD3 ζ significantly impaired the ability of this invariant chain to accumulate stably at the immunological synapse during T cell-APC interactions. Without its phosphoinositide-binding functions, CD3 ζ was concentrated in intracellular structures after T cell activation. Such findings demonstrate a novel functional role for CD3 ζ BRS-phosphoinositide interactions in supporting T cell activation.
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U2 - 10.4049/jimmunol.1002721
DO - 10.4049/jimmunol.1002721
M3 - Article
C2 - 21543646
AN - SCOPUS:79959542722
SN - 0022-1767
VL - 186
SP - 6839
EP - 6847
JO - Journal of Immunology
JF - Journal of Immunology
IS - 12
ER -