| Autor: |
Tsuchida, Shinobu, Yanagi, Shigeru, Inatome, Ryoko, Ding, Junyi, Hermann, Patrice, Tsujimura, Toshiaki, Matsui, Nobuzo, Yamamura, Hirohei |
| Předmět: |
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| Zdroj: |
Journal of Biochemistry; 2000, Vol. 127 Issue 2, p321-327, 7p |
| Abstrakt: |
Syk protein-tyrosine kinase (PTK) has been implicated in a variety of hematopoietic cell responses including immunoreceptor signaling. However, so far, there has been no evidence of the expression of Syk or Syk-related PTK in non-hematopoietic tissues. In this study, we have purified from, blood cell-depleted rat liver a 72-kDa cytoplasmic PTK which shows cross-reactivity with anti-Syk antibody. Partial amino acid sequence analysis revealed that this 72-kDa PTK is identical to Syk. Immunohistochemical and RT-PCR analyses demonstrated that Syk is expressed in human hepatocytes and two rat liver-derived cell lines, JTC-27 and RLC-16. Furthermore, Syk is significantly tyrosine-phos-phorylated in response to angiotensin II in JTC-27 cells, and angiotensin H-induced MAP kinase activation is blocked by the treatment of cells with a Syk-selective inhibitor, piceatannoL These results suggest that Syk plays an important role in signaling events of hepatocytes, such as signaling steps leading to MAP kinase activation by G-protein-coupled receptors. This is the first report of the expression of Syk in non-hematopoietic tissue [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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