title: mTORC1 alters the expression of glycolytic genes by regulating KPNA2 abundances.
abstract: Mammalian target of rapamycin complex 1 (mTORC1) plays important roles in regulating cell growth and proliferation, and the aberrant activation of mTORC1 has been observed in many human diseases. However, the proteins regulated by mTORC1 activation and their roles in mTORC1 downstream functions are still poorly understood. Using proteomic analysis, we found that proteins regulated by mTORC1 in MEFs could be categorized into eight functional groups including protein nuclear import and glycolysis. The positive regulation of Karyopherin subunit alpha-2 (KPNA2), an importer protein involved in protein nuclear import, by mTORC1 was verified in several other mouse and human cell lines. The regulation occurred at the transcriptional level, rather than at the level of S6K1- and 4E-BP1-dependent protein synthesis. KPNA2 knockdown partially blocked upregulation of glycolytic genes by mTORC1 activation, indicating that mTORC1 activation enhanced expression of glycolytic genes by increasing KPNA2 abundances. Furthermore, KPNA2 knockdown had no effects on the expression and subcellular localization of HIF1α, a transcription factor involved in regulating glycolytic genes downstream of mTORC1. In conclusion, our results proved that KPNA2 regulated the expression of glycolytic genes downstream of mTORC1 in a HIF1α-independent manner.
  
  
  CONCLUSIONS
  Identifying mTORC1-regulated proteins through proteomic method is a feasible way to study the downstream functions of mTORC1. In this study, we identified many mTORC1-regulated proteins using proteomic analysis by overlapping two different high vs low/no mTORC1 activity comparisons, TSC2(-/-) vs WT MEFs and TSC2(-/-) with/without rapamycin treatment. We found the abundances of many enzymes in glycolysis pathway and several proteins involved in protein nuclear import were positively regulated by mTORC1. More importantly, we first discovered that mTORC1 positively regulated the importer protein KPNA2, which participated in glycolysis regulation downstream of mTORC1 in a HIF1α-independent manner, indicating that mTORC1 regulates glycolysis through multiple ways.
authors: CAS Key Laboratory of Genome Sciences and Information, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: chenxw@big.ac.cn.
authors: Xianwei
authors: X
authors: Chen
authors: CAS Key Laboratory of Genome Sciences and Information, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: yhzhu@big.ac.cn.
authors: Yinghui
authors: Y
authors: Zhu
authors: CAS Key Laboratory of Genome Sciences and Information, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: wangzhaohui85@yahoo.com.
authors: Zhaohui
authors: Z
authors: Wang
authors: Beijing Protein Innovation, Beijing 101318, China. Electronic address: huishanzhu33@gmail.com.
authors: Huishan
authors: H
authors: Zhu
authors: CAS Key Laboratory of Genome Sciences and Information, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: panqf@big.ac.cn.
authors: Qingfei
authors: Q
authors: Pan
authors: CAS Key Laboratory of Genome Sciences and Information, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: susy@big.ac.cn.
authors: Siyuan
authors: S
authors: Su
authors: Beijing Protein Innovation, Beijing 101318, China. Electronic address: dongysh@genomics.cn.
authors: Yusheng
authors: Y
authors: Dong
authors: State Key Laboratory of Medical Molecular Biology, Department of Physiology, Institute of Basic Medical Sciences and School of Basic Medicine, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100005, China. Electronic address: rene_ll@126.com.
authors: Li
authors: L
authors: Li
authors: State Key Laboratory of Medical Molecular Biology, Department of Physiology, Institute of Basic Medical Sciences and School of Basic Medicine, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100005, China. Electronic address: hbzhang@ibms.pumc.edu.cn.
authors: Hongbing
authors: H
authors: Zhang
authors: CAS Key Laboratory of Genome Sciences and Information, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: wul@big.ac.cn.
authors: Lin
authors: L
authors: Wu
authors: CAS Key Laboratory of Genome Sciences and Information, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: louxm@big.ac.cn.
authors: Xiaomin
authors: X
authors: Lou
authors: CAS Key Laboratory of Genome Sciences and Information, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: siqiliu@big.ac.cn.
authors: Siqi
authors: S
authors: Liu
mesh_terms: D000818:Animals; D002461:Cell Line, Transformed; D039642:Eukaryotic Initiation Factors / Q000096:biosynthesis / Q000235:genetics; D005786:Gene Expression Regulation / Q000502:physiology*; D006019:Glycolysis / Q000502:physiology*; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism*; D000076222:Mechanistic Target of Rapamycin Complex 1; D051379:Mice; D018345:Mice, Knockout; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000096:biosynthesis / Q000235:genetics; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D028901:alpha Karyopherins
chemical_list: C491255:Eif4ebp2 protein, mouse; D039642:Eukaryotic Initiation Factors; C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; C490631:Kpna2 protein, mouse; D046912:Multiprotein Complexes; D009687:Nuclear Proteins; D028901:alpha Karyopherins; D000076222:Mechanistic Target of Rapamycin Complex 1; D038744:Ribosomal Protein S6 Kinases, 90-kDa; C512964:Rps6ka1 protein, mouse; D058570:TOR Serine-Threonine Kinases
keywords: Glycolysis; HIF1α; KPNA2; Proteomics; Rapamycin; mTORC1