In:
The Journal of Immunology, The American Association of Immunologists, Vol. 169, No. 6 ( 2002-09-15), p. 2813-2817
Abstract:
In resting T cells, Csk is constitutively localized in lipid rafts by virtue of interaction with a phosphorylated adaptor protein, Csk-binding protein (Cbp)/phosphoprotein associated with glycolipid-enriched microdomains, and sets an activation threshold in TCR signaling. In this study, we examined a kinase responsible for Cbp phosphorylation in T cell membrane rafts. By analyzing T cells from Fyn−/− mice, we clearly demonstrated that Fyn, but not Lck, has its kinase activity in membrane rafts, and plays a critical role in Cbp phosphorylation, Cbp-Csk interaction, and Csk kinase activity. Naive CD44lowCD62 ligandhigh T cells were substantially reduced in Fyn−/− mice, presumably due to the inhibition of Cbp phosphorylation. Thus, Fyn mediates Cbp-Csk interaction and recruits Csk to rafts by phosphorylating Cbp. Csk recruited to rafts would then be activated and inhibit the kinase activity of Lck to keep resting T cells in a quiescent state. Our results elucidate a negative regulatory role for Fyn in proximal TCR signaling in lipid rafts.
Type of Medium:
Online Resource
ISSN:
0022-1767
,
1550-6606
DOI:
10.4049/jimmunol.169.6.2813
Language:
English
Publisher:
The American Association of Immunologists
Publication Date:
2002
detail.hit.zdb_id:
1475085-5
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