Regulation of TRPC6 channel activity by tyrosine phosphorylation
Regulation of TRPC6 channel activity by tyrosine phosphorylation
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DOI：
10.1074/jbc.m311274200
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发表时间：
2004-04-30
影响因子：
4.8
通讯作者：
Mikoshiba, K
中科院分区：
文献类型：
--
作者：
Hisatsune, C;Kuroda, Y;Mikoshiba, K
各种激素刺激和生长因子通过磷脂酶C（PLC）激活来激活哺乳动物典型瞬时受体电位（TRPC）通道。然而，TRPC通道活性调节的确切机制仍然未知。在这里，我们提供了第一个证据，直接酪氨酸磷酸化的Src家族蛋白酪氨酸激酶（PTKs）是一种新的机制，调节TRPC 6通道的活性。我们发现TRPC 6在COS-7细胞中与Src家族PTKs的成员Fyn共表达时被酪氨酸磷酸化。我们还发现Fyn与TRPC 6相互作用，并且这种相互作用是由Fyn的SH 2结构域和TRPC 6的N-末端区域以磷酸化非依赖的方式介导的。此外，我们证明了TRPC 6与Fyn在哺乳动物大脑中的物理关联。此外，我们发现，刺激表皮生长因子受体诱导快速酪氨酸磷酸化的TRPC 6在COS-7细胞。这种表皮生长因子诱导的TRPC 6酪氨酸磷酸化被PP 2（Src家族PTKs的特异性抑制剂）和显性负性形式的Fyn显著阻断，表明Src家族PTKs直接磷酸化TRPC 6可能是由生理刺激引起的。此外，使用单通道记录，我们发现Fyn通过酪氨酸磷酸化调节TRPC 6通道活性。因此，我们的研究结果表明，Src家族PTKs的酪氨酸磷酸化是TRPC 6通道活性的一种新的调节机制。
Various hormonal stimuli and growth factors activate the mammalian canonical transient receptor potential ( TRPC) channel through phospholipase C ( PLC) activation. However, the precise mechanism of the regulation of TRPC channel activity remains unknown. Here, we provide the first evidence that direct tyrosine phosphorylation by Src family protein-tyrosine kinases (PTKs) is a novel mechanism for modulating TRPC6 channel activity. We found that TRPC6 is tyrosine-phosphorylated in COS-7 cells when coexpressed with Fyn, a member of the Src family PTKs. We also found that Fyn interacts with TRPC6 and that the interaction is mediated by the SH2 domain of Fyn and the N-terminal region of TRPC6 in a phosphorylation-independent manner. In addition, we demonstrated the physical association of TRPC6 with Fyn in the mammalian brain. Moreover, we showed that stimulation of the epidermal growth factor receptor induced rapid tyrosine phosphorylation of TRPC6 in COS-7 cells. This epidermal growth factor-induced tyrosine phosphorylation of TRPC6 was significantly blocked by PP2, a specific inhibitor of Src family PTKs, and by a dominant negative form of Fyn, suggesting that the direct phosphorylation of TRPC6 by Src family PTKs could be caused by physiological stimulation. Furthermore, using single channel recording, we showed that Fyn modulates TRPC6 channel activity via tyrosine phosphorylation. Thus, our findings demonstrated that tyrosine phosphorylation by Src family PTKs is a novel regulatory mechanism of TRPC6 channel activity.