Deficiency in mTORC1-controlled C/EBPβ-mRNA translation improves metabolic health in mice


  • L.M. Zidek
  • T. Ackermann
  • G. Hartleben
  • S. Eichwald
  • G. Kortman
  • M. Kiehntopf
  • A. Leutz
  • N. Sonenberg
  • Z.Q. Wang
  • J. von Maltzahn
  • C. Müller
  • C.F. Calkhoven


  • EMBO Reports


  • EMBO Rep 16 (08): 1022-1036


  • The mammalian target of rapamycin complex 1 (mTORC1) is a central regulator of physiological adaptations in response to changes in nutrient supply. Major downstream targets of mTORC1 signalling are the mRNA translation regulators p70 ribosomal protein S6 kinase 1 (S6K1p70) and the 4E-binding proteins (4E-BPs). However, little is known about vertebrate mRNAs that are specifically controlled by mTORC1 signalling and are engaged in regulating mTORC1-associated physiology. Here, we show that translation of the CCAAT/enhancer binding protein beta (C/EBP{beta}) mRNA into the C/EBP{beta}-LIP isoform is suppressed in response to mTORC1 inhibition either through pharmacological treatment or through calorie restriction. Our data indicate that the function of 4E-BPs is required for suppression of LIP. Intriguingly, mice lacking the cis-regulatory upstream open reading frame (uORF) in the C/EBP{beta}-mRNA, which is required for mTORC1-stimulated translation into C/EBP{beta}-LIP, display an improved metabolic phenotype with features also found under calorie restriction. Thus, our data suggest that translational adjustment of C/EBP{beta}-isoform expression is one of the key processes that direct metabolic adaptation in response to changes in mTORC1 activity.