A small molecule inhibitor of Rheb selectively targets mTORC1 signaling

• Published in: Nature communications 2018-02, Vol.9 (1), p.548-12, Article 548
• Main Authors: Mahoney, Sarah J., Narayan, Sridhar, Molz, Lisa, Berstler, Lauren A., Kang, Seong A., Vlasuk, George P., Saiah, Eddine
• Format: Article
• Language: English
• Subjects: 13; 13/106; 13/95; 14/1; 140/131; 49; 49/98; 631/154/309/2144; 631/154/436/2388; 631/154/556; 631/80/86/2368; 64/60; Aberration; AKT protein; Animals; Cell Line, Tumor; Crystallography, X-Ray; Extracellular signal-regulated kinase; Fibrosis; Glutamic acid receptors; HEK293 Cells; Humanities and Social Sciences; Humans; Inhibition; Jurkat Cells; Kidneys; Kinases; Male; MCF-7 Cells; Mechanistic Target of Rapamycin Complex 1 - metabolism; Metabolism; Mice, Inbred C57BL; Molecular Structure; multidisciplinary; Muscles; Mutation; N-Methyl-D-aspartic acid receptors; Neurodegenerative diseases; Neurological diseases; Pharmacology; Phosphorylation; Phosphorylation - drug effects; Rapamycin; Ras Homolog Enriched in Brain Protein - antagonists & inhibitors; Ras Homolog Enriched in Brain Protein - genetics; Ras Homolog Enriched in Brain Protein - metabolism; Ribosomal protein S6; Ribosomal protein S6 kinase; Ribosomal Protein S6 Kinases, 70-kDa - metabolism; Science; Science (multidisciplinary); Signal Transduction - drug effects; Signaling; Small Molecule Libraries - chemistry; Small Molecule Libraries - pharmacology; TOR protein
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-03035-z

The small G-protein Rheb activates the mechanistic target of rapamycin complex 1 (mTORC1) in response to growth factor signals. mTORC1 is a master regulator of cellular growth and metabolism; aberrant mTORC1 signaling is associated with fibrotic, metabolic, and neurodegenerative diseases, cancers, and rare disorders. Point mutations in the Rheb switch II domain impair its ability to activate mTORC1. Here, we report the discovery of a small molecule ( NR1 ) that binds Rheb in the switch II domain and selectively blocks mTORC1 signaling. NR1 potently inhibits mTORC1 driven phosphorylation of ribosomal protein S6 kinase beta-1 (S6K1) but does not inhibit phosphorylation of AKT or ERK. In contrast to rapamycin, NR1 does not cause inhibition of mTORC2 upon prolonged treatment. Furthermore, NR1 potently and selectively inhibits mTORC1 in mouse kidney and muscle in vivo. The data presented herein suggest that pharmacological inhibition of Rheb is an effective approach for selective inhibition of mTORC1 with therapeutic potential. Aberrant mTORC1 signaling is linked to several chronic diseases. Here, the authors develop a small molecule inhibitor that binds the small G-protein Rheb and selectively blocks mTORC1 signaling, holding potential for therapeutic applications.