Tyrosine phosphorylation of caveolin-1 in the endothelium
Tyrosine phosphorylation of caveolin-1 in the endothelium
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DOI：
10.1006/excr.1999.4652
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发表时间：
1999-12-15
影响因子：
3.7
通讯作者：
Fujimoto, T
中科院分区：
文献类型：
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作者：
Aoki, T;Nomura, R;Fujimoto, T
Caveolin-1 是小窝的一种支架蛋白，已知可被 Src 激酶酪氨酸磷酸化。最近，我们生成了一种针对酪氨酸 14 (PY14) 磷酸化的 Caveolin-1 的特异性抗体（R. Nomura 和 T. Fujimoto, 1999, Mol. Biol. Cell 10, 975-986）。在本研究中，通过将PY14应用于正常大鼠组织切片，我们发现caveolin-1的酪氨酸磷酸化发生在有限的位置，包括连续毛细血管和小静脉的内皮。在标准培养条件下，培养的内皮细胞不被 PY14 标记，但当暴露于氧化应激和/或酪氨酸磷酸酶抑制剂时，PY14 会被阳性标记。用除草霉素 A 或金雀异黄素预处理细胞可抑制该反应。血管活性试剂或物理刺激不会引起磷酸化。伴随着酪氨酸磷酸化，内陷小凹的数量急剧减少，细胞质中出现了强烈标记的小凹蛋白-1的囊泡；囊泡的平均直径大于小窝的平均直径。结果表明，在体内正常大鼠内皮细胞中，caveolin-1 的酪氨酸磷酸化发生在酪氨酸-14 处，并且可能诱导小凹囊泡形成和/或融合。 (C) 1999 年学术出版社。
Caveolin-1, a scaffolding protein of caveolae, is known to be tyrosine-phosphorylated by Src kinases. Recently we generated a specific antibody to caveolin-1 phosphorylated at tyrosine-14 (PY14) (R. Nomura and T. Fujimoto, 1999, Mol. Biol. Cell 10, 975-986). In the present study, by applying PY14 to sections of normal rat tissues, we found that tyrosine phosphorylation of caveolin-1 occurred in limited locations, including the endothelium of the continuous capillaries and small venules. Cultured endothelial cells were not labeled by PY14 under a standard culture condition, but became positively labeled when exposed to oxidative stresses and/or tyrosine phosphatase inhibitors. The reaction was prohibited by pretreating the cells with herbimycin A or genistein. Vasoactive reagents or physical stimuli did not cause the phosphorylation. Concomitant with the tyrosine phosphorylation, the number of invaginated caveolae decreased drastically, and vesicles labeled intensely for caveolin-1 appeared in the cytoplasm; the average diameter of the vesicles was larger than that of caveolae. The result implies that tyrosine phosphorylation of caveolin-1 occurs at tyrosine-14 in the normal rat endothelium in vivo and may induce caveolar vesiculation and/or fusion. (C) 1999 Academic Press.