GSK3beta positively regulates Hedgehog signaling through Sufu in mammalian cells.
GSK3beta positively regulates Hedgehog signaling through Sufu in mammalian cells.
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DOI：
10.1016/j.bbrc.2006.12.058
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发表时间：
2007-02
影响因子：
3.1
通讯作者：
K. Takenaka;Yoshiaki Kise;H. Miki
中科院分区：
文献类型：
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作者：
K. Takenaka;Yoshiaki Kise;H. Miki
Hedgehog信号在多细胞生物的胚胎发育中起着重要的作用。该途径最终由锌指转录因子Gli传递，其活性被Sufu抑制，Sufu是该信号传导的负调节剂。为了更详细地阐明这种调节，我们筛选了Sufu结合蛋白。我们通过质谱分析确定了GSK3β为腐乳的特异性结合伴侣。GSK 3 β与腐乳在体内外均存在结合。在Hedgehog应答细胞中通过RNAi下调GSK3β表达减弱了Hedgehog信号传导，表明GSK3β作为Hedgehog信号传导的正调节剂起作用。此外，体外激酶试验表明，GSK 3 β磷酸化Sufu和Sufu磷酸化模拟突变体与Gli1结合的能力显著降低，不能有效抑制Gli1介导的报告基因表达。这些结果有力地表明，GSK 3 β磷酸化腐乳以正向调节哺乳动物细胞中的Hedgehog信号传导。
Hedgehog signaling plays important roles in embryonic patterning of multicellular organisms. This pathway is ultimately transmitted by the zinc-finger transcriptional factor Gli, of which activity is suppressed by Sufu, a negative regulator of this signaling. To clarify this regulation to more detail, we screened for Sufu-binding proteins. We identified GSK3β as a specific binding partner of Sufu by mass spectrometric analysis. GSK3β bound to Sufu both in vitro and in vivo. Down-regulation of GSK3β expression by RNAi in Hedgehog-responsive cells attenuated Hedgehog signaling, suggesting that GSK3β functions as a positive regulator of Hedgehog signaling. In addition, an in vitro kinase assay showed that GSK3β phosphorylates Sufu and phosphorylation-mimicking mutant of Sufu showed significantly decreased ability to bind Gli1 and could not suppress the Gli-mediated expression of a reporter gene efficiently. These results strongly suggest that GSK3β phosphorylates Sufu to positively regulate Hedgehog signaling in mammalian cells.