Constitutively active NDR1-PIF kinase functions independent of MST1 and hMOB1 signalling.
Constitutively active NDR1-PIF kinase functions independent of MST1 and hMOB1 signalling.
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DOI：
10.1016/j.cellsig.2014.04.011
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发表时间：
2014-08
影响因子：
4.8
通讯作者：
Hergovich A
中科院分区：
文献类型：
--
作者：
Cook D;Hoa LY;Gomez V;Gomez M;Hergovich A
人类MST1/hMOB1/NDR1抑癌素级联调控重要的细胞过程，如中心体复制。HMOB1/NDR1复合体的形成似乎是通过Ser281上的自动磷酸化和MST1在Thr444处的疏水基序(HM)磷酸化激活NDR1所必需的。为了剖析MST1/hMOB1/NDR信号转导中的这些机制关系，我们设计了NDR1变体，携带模拟HM磷酸化和/或取消hMOB1/NDR1相互作用的修饰。值得注意的是，对这些变体的分析表明，包含PRK2疏水基序的NDR1变体NDR1-PIF仍然高度活跃，不依赖于hMOB1/NDR1-PIF复合体的形成。相反，正如T444A磷酸受体突变体所报道的那样，在HM磷酸化位点上携带单一模拟磷酸突变的NDR1版本，即T444D或T444E，不显示出增强的激酶活性。综上所述，这些观察表明，在细胞中，MST1对Thr444的磷酸化取决于hMOB1/NDR1的结合，而NDR1的Ser281自动磷酸化可以独立发生。通过在NDR1或MST1缺失的细胞中测试中心体靶向的NDR1变体，我们进一步观察到，中心体丰富的NDR1-PIF既不需要hMOB1结合，也不需要MST1信号来发挥中心体过度重复的功能。综上所述，我们对NDR1版本的生化和细胞生物学特征为NDR1和NDR1的S在中心体复制中的调控机制提供了新的意想不到的见解。
The human MST1/hMOB1/NDR1 tumour suppressor cascade regulates important cellular processes, such as centrosome duplication. hMOB1/NDR1 complex formation appears to be essential for NDR1 activation by autophosphorylation on Ser281 and hydrophobic motif (HM) phosphorylation at Thr444 by MST1. To dissect these mechanistic relationships in MST1/hMOB1/NDR signalling, we designed NDR1 variants carrying modifications that mimic HM phosphorylation and/or abolish hMOB1/NDR1 interactions. Significantly, the analyses of these variants revealed that NDR1-PIF, an NDR1 variant containing the PRK2 hydrophobic motif, remains hyperactive independent of hMOB1/NDR1-PIF complex formation. In contrast, as reported for the T444A phospho-acceptor mutant, NDR1 versions carrying single phospho-mimicking mutations at the HM phosphorylation site, namely T444D or T444E, do not display increased kinase activities. Collectively, these observations suggest that in cells Thr444 phosphorylation by MST1 depends on the hMOB1/NDR1 association, while Ser281 autophosphorylation of NDR1 can occur independently. By testing centrosome-targeted NDR1 variants in NDR1- or MST1-depleted cells, we further observed that centrosome-enriched NDR1-PIF neither requires hMOB1 binding nor MST1 signalling to function in centrosome overduplication. Taken together, our biochemical and cell biological characterisation of NDR1 versions provides novel unexpected insights into the regulatory mechanisms of NDR1 and NDR1’s role in centrosome duplication.
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影响因子：
7.3
作者：
Avruch, Joseph;Zhou, Dawang;Fitamant, Julien;Bardeesy, Nabeel;Mou, Fan;Barrufet, Laura Regue
通讯作者：
Barrufet, Laura Regue
影响因子：
9.2
作者：
Oh, Hyun Jung;Kim, Mi Ju;Lim, Dae-Sik
通讯作者：
Lim, Dae-Sik
影响因子：
5.3
作者：
Kohler, Reto S.;Schmitz, Debora;Hergovich, Alexander
通讯作者：
Hergovich, Alexander
影响因子：
4.8
作者：
Bichsel, SJ;Tamaskovic, R;Hemmings, BA
通讯作者：
Hemmings, BA
影响因子：
5.3
作者：
Stegert, MR;Hergovich, A;Hemmings, BA
通讯作者：
Hemmings, BA