| Autor: |
Ding, Junyi, Takano, Tomoko, Hermann, Patrice, Gao, Sanyang, Han, Weihong, Noda, Chiseko, Yanagi, Shigeru, Yamamura, Hirohei |
| Předmět: |
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| Zdroj: |
Journal of Biochemistry; 2000, Vol. 127 Issue 5, p791-796, 6p |
| Abstrakt: |
Syk plays a crucial role in the transduction of oxidative stress signaling. In this paper, we investigated the roles of Src homology 2 (SH2) domains of Syk in oxidative stress signaling, using Syk-negative DT40 cells expressing the N- or C-terminal SH2 domain mutant [mSH2(N) or mSH2(C)] of Syk. Tyrosine phosphorylation of Syk in cells expressing mSH2(N) Syk after H2O2 treatment was higher than that in cells expressing wild-type Syk or mSH2(C) Syk. The tyrosine phosphorylation of wild-type Syk and mSH2(C) Syk, but not that of mSH2(N), was sensitive to PP2, a specific inhibitor of Src-family pro-tein-tyrosine kinase. In oxidative stress, the C-terminal SH2 domain of Syk was demonstrated to be required for induction of tyrosine phosphorylation of cellular proteins, phospholipase C (PLC-γ2 phosphorylation, inositol 1,4,5-triphosphate (IP3 generation, Ca2+ release from intracellular stores, and c-Jun N-terminal kinase activation. In contrast, in mSH2(N) Syk-expressing cells, tyrosine phosphorylation of intracellular proteins including PLC-γ2 was markedly induced in oxidative stress. The enhanced phosphorylation of mSH2(N) Syk and PLC-γ2, however, did not link to Ca2+ mobilization from intracellular pools and IP3 generation. Thus, the N- and C-terminal SH2 domains of Syk possess distinctive functions in oxidative stress signaling [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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