Dynasore impairs VEGFR2 signalling in an endocytosis-independent manner.
Dynasore impairs VEGFR2 signalling in an endocytosis-independent manner.
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DOI：
10.1038/srep45035
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发表时间：
2017-03-22
影响因子：
4.6
通讯作者：
Christoforidis S
中科院分区：
文献类型：
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作者：
Basagiannis D;Zografou S;Galanopoulou K;Christoforidis S
VEGFR 2是一种重要的血管生成受体，在血管稳态中起关键作用。在被VEGF激活后，VEGFR 2被内吞。VEGFR 2的内化部分地通过网格蛋白介导的内吞作用（CME）来促进，其在VEGFR 2功能中的作用是有争议的。在这里，我们证实了CME在VEGFR 2摄取中的贡献。然而，奇怪的是，我们发现，不同的方法抑制CME发挥矛盾的影响VEGF信号转导;敲低网格蛋白，或发动蛋白，或过表达的发动蛋白K44 A，不影响VEGF诱导的ERK 1/2的磷酸化，而dynasore引起强烈的抑制。我们通过显示尽管dynasore抑制VEGFR 2的CME，但其对ERK 1/2磷酸化的抑制作用与VEGFR 2内吞作用的减弱无关，而是由于药物的脱靶效应而解决了这一差异。Dynasore抑制VEGF诱导的钙释放，这是一种位于ERK 1/2上游的信号传导事件，这意味着这种作用可能是药物对VEGF至ERK 1/2信号传导的抑制作用的部分原因。这些结果提出了警告，虽然dynasore在抑制网格蛋白和发动蛋白介导的内吞作用方面具有特异性，但它也可能对信号传导分子产生脱靶效应，从而影响对内吞作用在信号传导中作用的解释。
VEGFR2 is a critical angiogenic receptor playing a key role in vascular homeostasis. Upon activation by VEGF, VEGFR2 becomes endocytosed. Internalisation of VEGFR2 is facilitated, in part, through clathrin mediated endocytosis (CME), the role of which in VEGFR2 function is debated. Here, we confirm the contribution of CME in VEGFR2 uptake. However, curiously, we find that different approaches of inhibition of CME exert contradictory effects on VEGF signalling; knockdown of clathrin, or of dynamin, or overexpression of dynamin K44A, do not affect VEGF-induced phosphorylation of ERK1/2, while dynasore causes strong inhibition. We resolve this discrepancy by showing that although dynasore inhibits CME of VEGFR2, its inhibitory action in ERK1/2 phosphorylation is not related to attenuation of VEGFR2 endocytosis; it is rather due to an off-target effect of the drug. Dynasore inhibits VEGF-induced calcium release, a signalling event that lies upstream of ERK1/2, which implies that this effect could be responsible, at least in part, for the inhibitory action of the drug on VEGF-to-ERK1/2 signalling. These results raise caution that although dynasore is specific in inhibiting clathrin- and dynamin-mediated endocytosis, it may also exert off-target effects on signalling molecules, hence influencing the interpretation of the role of endocytosis in signalling.