Zhu M, John S, Berg M, Leonard W J
Laboratory of Molecular Immunology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892-1674, USA.
Cell. 1999 Jan 8;96(1):121-30. doi: 10.1016/s0092-8674(00)80965-4.
Using the coiled-coil region of Stat5b as the bait in a yeast two-hybrid screen, we identified the association of Nmi, a protein of unknown function previously reported as an N-Myc interactor. We further show that Nmi interacts with all STATs except Stat2. We evaluated two cytokine systems, IL-2 and IFNgamma, and demonstrate that Nmi augments STAT-mediated transcription in response to these cytokines. Interestingly, Nmi lacks an intrinsic transcriptional activation domain; instead, Nmi enhances the association of CBP/p300 coactivator proteins with Stat1 and Stat5, and together with CBP/p300 can augment IL-2- and IFNgamma-dependent transcription. Therefore, our data not only reveal that Nmi can potentiate STAT-dependent transcription, but also suggest that it can augment coactivator protein recruitment to at least some members of a group of sequence-specific transcription factors.
在酵母双杂交筛选中，我们以Stat5b的卷曲螺旋区域作为诱饵，鉴定出Nmi（一种功能未知的蛋白质，先前报道为N-Myc相互作用蛋白）之间的关联。我们进一步表明，Nmi与除Stat2之外的所有STAT相互作用。我们评估了两种细胞因子系统，即IL-2和IFNγ，并证明Nmi在响应这些细胞因子时增强了STAT介导的转录。有趣的是，Nmi缺乏内在的转录激活结构域；相反，Nmi增强了CBP/p300共激活蛋白与Stat1和Stat5的结合，并且与CBP/p300一起可以增强IL-2和IFNγ依赖性转录。因此，我们的数据不仅揭示了Nmi可以增强STAT依赖性转录，还表明它可以增加共激活蛋白对一组序列特异性转录因子中至少一些成员的募集。
