, Volume 39, Issue 4, pp 419–428 | Cite as

A system to identify inhibitors of mTOR signaling using high-resolution growth analysis in Saccharomyces cerevisiae

  • Mitchell B. Lee
  • Daniel T. Carr
  • Michael G. Kiflezghi
  • Yan Ting Zhao
  • Deborah B. Kim
  • Socheata Thon
  • Margarete D. Moore
  • Mary Ann K. Li
  • Matt KaeberleinEmail author
Original Article


The mechanistic target of rapamycin (mTOR) is a central regulator of growth and proliferation and mTOR inhibition is a promising therapy for a variety of diseases and disorders. Inhibition of mTOR complex I (mTORC1) with rapamycin delays aging and increases healthy longevity in laboratory animals and is used clinically at high doses to prevent organ transplant rejection and to treat some forms of cancer. Clinical use of rapamycin is associated with several unwanted side effects, however, and several strategies are being taken to identify mTORC1 inhibitors with fewer side effects. We describe here a yeast-based growth assay that can be used to screen for novel inhibitors of mTORC1. By testing compounds using a wild-type strain and isogenic cells lacking either TOR1 or FPR1, we can resolve not only whether a compound is an inhibitor of mTORC1 but also whether the inhibitor acts through a mechanism similar to rapamycin by binding Fpr1. Using this assay, we show that rapamycin derivatives behave similarly to rapamycin, while caffeine and the ATP competitive inhibitors Torin 1 and GSK2126458 are mTORC1 inhibitors in yeast that act independently of Fpr1. Some mTOR inhibitors in mammalian cells do not inhibit mTORC1 in yeast, and several nutraceutical compounds were not found to specifically inhibit mTOR but resulted in a general inhibition of yeast growth. Our screening method holds promise as a means of effectively assaying drug libraries for mTOR-inhibitory molecules in vivo that may be adapted as novel treatments to fight diseases and extend healthy longevity.


mTOR Saccharomyces cerevisiae Yeast 



This work was supported by the University of Washington Nathan Shock Center of Excellence in the Basic Biology of Aging Invertebrate Longevity and Healthspan Core (P30AG013280) and a grant to MK from USANA Health Sciences. MBL was supported by the Howard Hughes Medical Institute (HHMI) Gilliam Fellowship for Advanced Study, the National Institutes of Health (NIH) Cellular and Molecular Biology training grant (T32GM7270-39), and the University of Washington Graduate Opportunities and Minority Achievement Program (UW GO-MAP) Bank of America Fellowship.

Supplementary material

11357_2017_9988_MOESM1_ESM.pdf (162 kb)
Supplementary Figure 1 (PDF 162 kb).
11357_2017_9988_MOESM2_ESM.pdf (307 kb)
Supplementary Figure 2 (PDF 306 kb).
11357_2017_9988_MOESM3_ESM.pdf (45 kb)
Supplementary Table 1 (PDF 44 kb).
11357_2017_9988_MOESM4_ESM.pdf (45 kb)
Supplementary Table 2 (PDF 45 kb).


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Copyright information

© American Aging Association 2017

Authors and Affiliations

  • Mitchell B. Lee
    • 1
  • Daniel T. Carr
    • 1
  • Michael G. Kiflezghi
    • 1
    • 2
  • Yan Ting Zhao
    • 1
  • Deborah B. Kim
    • 1
  • Socheata Thon
    • 1
  • Margarete D. Moore
    • 1
  • Mary Ann K. Li
    • 1
  • Matt Kaeberlein
    • 1
    Email author
  1. 1.Department of PathologyUniversity of WashingtonSeattleUSA
  2. 2.Molecular Medicine and Mechanisms of Disease (M3D) ProgramUniversity of WashingtonSeattleUSA

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