Yoon Sang-Oh, Shin Sejeong, Liu Yuzhen, Ballif Bryan A, Woo Michele S, Gygi Steven P, Blenis John
Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.
Mol Cell. 2008 Feb 15;29(3):362-75. doi: 10.1016/j.molcel.2007.12.024.
The major participants of the Ras/ERK and PI3-kinase (PI3K) pathways are well characterized. The cellular response to activation of these pathways, however, can vary dramatically. How differences in signal strength, timing, spatial location, and cellular context promote specific cell-fate decisions remains unclear. Nuclear transport processes can have a major impact on the determination of cell fate; however, little is known regarding how nuclear transport is regulated by or regulates these pathways. Here we show that RSK and Akt, which are activated downstream of Ras/ERK and PI3K, respectively, modulate the Ran gradient and nuclear transport by interacting with, phosphorylating, and regulating Ran-binding protein 3 (RanBP3) function. Our findings highlight an important link between two major cell-fate determinants: nuclear transport and the Ras/ERK/RSK and PI3K/Akt signaling pathways.
Ras/ERK和PI3激酶(PI3K)信号通路的主要参与者已得到充分表征。然而,细胞对这些通路激活的反应可能有很大差异。信号强度、时间、空间位置和细胞环境的差异如何促进特定的细胞命运决定仍不清楚。核运输过程可能对细胞命运的决定产生重大影响;然而,关于核运输如何被这些通路调控或如何调控这些通路,我们知之甚少。在这里,我们表明,分别在Ras/ERK和PI3K下游被激活的RSK和Akt,通过与Ran结合蛋白3(RanBP3)相互作用、磷酸化并调节其功能,来调节Ran梯度和核运输。我们的研究结果突出了两个主要细胞命运决定因素之间的重要联系:核运输与Ras/ERK/RSK和PI3K/Akt信号通路。