First Author | Fukai I | Year | 2000 |
Journal | Eur J Immunol | Volume | 30 |
Issue | 12 | Pages | 3507-15 |
PubMed ID | 11093170 | Mgi Jnum | J:71768 |
Mgi Id | MGI:2150784 | Doi | 10.1002/1521-4141(2000012)30:12<3507::AID-IMMU3507>3.0.CO;2-O |
Citation | Fukai I, et al. (2000) A critical role for p59(fyn) in CD2-based signal transduction. Eur J Immunol 30(12):3507-15 |
abstractText | TCR- but not CD2-triggered IL-2 production is p56(lck) dependent. To test the hypothesis that p59(fyn), a second src-family protein tyrosine kinase (PTK) expressed in T lymphocytes, might be an essential upstream component of the CD2 signaling pathway, we generated human (h) CD2 transgenic (tg) fyn(+/+) and fyn(-/-) mice. Clustering of hCD2 molecules on resting peripheral T lymphocytes results in Ca(2+) mobilization, activation of MAPK and cellular proliferation. In contrast, in the absence of p59(fyn), these CD2-initiated activities are markedly reduced, while TCR-triggered proliferation is unaffected. Several CD2 pathway components regulated by p59(fyn) have been identified including phospholipase C-gamma1 (PLC-gamma1), Vav, protein kinase C-theta isoform (PKC-theta), docking protein (Dok), focal adhesion kinase (FAK) and Pyk2. Decreased inducible PKC-theta catalytic activity and Vav phosphorylation likely account for diminished p38 and JNK activation in hCD2tg fyn(-/-) mice. Moreover, deficiency in fyn-dependent PLC-gamma1 catalytic activity may contribute to reduced PKC-alpha-dependent ERK activation. Of note, CD2-dependent Dok but not linker from activated T cells (LAT) tyrosine phosphorylation requires p59(fyn). Furthermore, that FAK and Pyk2 are target substrates implies that p59(fyn) may be an important regulator of T cell adhesion as well. Collectively, these data identify p59(fyn) as a key PTK in CD2-mediated activation of mature T lymphocytes. |