French Jarrod B, Jones Sara A, Deng Huayun, Pedley Anthony M, Kim Doory, Chan Chung Yu, Hu Haibei, Pugh Raymond J, Zhao Hong, Zhang Youxin, Huang Tony Jun, Fang Ye, Zhuang Xiaowei, Benkovic Stephen J
Department of Biochemistry and Cell Biology, Department of Chemistry, Stony Brook University, Stony Brook, NY 11794, USA.
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
Science. 2016 Feb 12;351(6274):733-7. doi: 10.1126/science.aac6054.
Purine biosynthetic enzymes organize into dynamic cellular bodies called purinosomes. Little is known about the spatiotemporal control of these structures. Using super-resolution microscopy, we demonstrated that purinosomes colocalized with mitochondria, and these results were supported by isolation of purinosome enzymes with mitochondria. Moreover, the number of purinosome-containing cells responded to dysregulation of mitochondrial function and metabolism. To explore the role of intracellular signaling, we performed a kinome screen using a label-free assay and found that mechanistic target of rapamycin (mTOR) influenced purinosome assembly. mTOR inhibition reduced purinosome-mitochondria colocalization and suppressed purinosome formation stimulated by mitochondria dysregulation. Collectively, our data suggest an mTOR-mediated link between purinosomes and mitochondria, and a general means by which mTOR regulates nucleotide metabolism by spatiotemporal control over protein association.
嘌呤生物合成酶组装成称为嘌呤体的动态细胞结构。人们对这些结构的时空控制知之甚少。利用超分辨率显微镜，我们证明嘌呤体与线粒体共定位，并且通过将嘌呤体酶与线粒体分离也证实了这些结果。此外，含嘌呤体细胞的数量对线粒体功能和代谢的失调有反应。为了探究细胞内信号传导的作用，我们使用无标记检测法进行了激酶组筛选，发现雷帕霉素的作用靶点（mTOR）影响嘌呤体的组装。mTOR抑制减少了嘌呤体与线粒体的共定位，并抑制了由线粒体失调刺激引起的嘌呤体形成。总体而言，我们的数据表明mTOR介导了嘌呤体与线粒体之间的联系，以及一种mTOR通过对蛋白质结合的时空控制来调节核苷酸代谢的一般方式。
