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Published July 2010 | Supplemental Material + Accepted Version
Journal Article Open

Chemical genetics screen for enhancers of rapamycin identifies a specific inhibitor of an SCF family E3 ubiquitin ligase


The target of rapamycin (TOR) plays a central role in eukaryotic cell growth control. With prevalent hyperactivation of the mammalian TOR (mTOR) pathway in human cancers, strategies to enhance TOR pathway inhibition are needed. We used a yeast-based screen to identify small-molecule enhancers of rapamycin (SMERs) and discovered an inhibitor (SMER3) of the Skp1-Cullin-F-box (SCF)^(Met30) ubiquitin ligase, a member of the SCF E3-ligase family, which regulates diverse cellular processes including transcription, cell-cycle control and immune response. We show here that SMER3 inhibits SCF^(Met30) in vivo and in vitro, but not the closely related SCF^(Cdc4). Furthermore, we demonstrate that SMER3 diminishes binding of the F-box subunit Met30 to the SCF core complex in vivo and show evidence for SMER3 directly binding to Met30. Our results show that there is no fundamental barrier to obtaining specific inhibitors to modulate function of individual SCF complexes.

Additional Information

© 2010 Nature Publishing Group. Received 9 March; accepted 9 May; published online 27 June 2010. We are grateful for grant support from the American Cancer Society and the U.S. National Institutes of Health and for traineeship support of M.A. and B.L. by the NIH UCLA Chemistry−Biology Interface Predoctoral Training Program. N.Z. and R.J.D. are investigators of the Howard Hughes Medical Institute. We thank D. Skowyra (Saint Louis University) and M. Tyers (University of Edinburgh, UK) for their generous gifts of bacculo virus constructs and anti-Met4 antibody, respectively. We also thank J. Salcedo (Roche Diagnostics Corporation) for support toward differential scanning fluorimetry experiments. Author Contributions: Figure 1a, M.A. and R.D.; 1b, F.F. and M.L.; 1c, C.L. and J.H.; 2a, N.J.; 2b, N.J. and R.H.; 2c, K.F.; 2d,e, I.O. and N.P.; 3a, K.F.; 3b, K.F. and L.H.; 3c, K.F.; 3d, N.J.; 3e, M.A.; Table 1, X.T., M.A. and P.M.d.M.; X.C., B.L., R.V., Y.L., K.N.H., M.E.J. and N.Z. contributed new reagents and analysis; all authors discussed data; M.A., F.F., M.E.J., R.J.D., P.K. and J.H. wrote the paper with input from all authors.

Attached Files

Accepted Version - nihms-203763.pdf

Supplemental Material - nbt.1645-S1.pdf

Supplemental Material - nbt.1645-S2.xls

Supplemental Material - nbt.1645-S3.xls


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August 19, 2023
October 20, 2023