Small-molecule allosteric activator of ubiquitin-specific protease 7 (USP7)

I Isabella Jaen Maisonet (Department of Cancer Biology, Dana-Farber Cancer Institute) M Mona Sharafi (Department of Cancer Biology, Dana-Farber Cancer Institute) E Emilie J. Korchak (Department of Molecular Biology and Biophysics, University of Connecticut) A Andres Salazar-Chaparro (Department of Cancer Biology, Dana-Farber Cancer Institute) A Ariana S. Bratt (Department of Cancer Biology, Dana-Farber Cancer Institute) T Tvesha Parikh (Department of Molecular Biology and Biophysics, University of Connecticut) A Anthony C. Varca (Department of Cancer Biology, Dana-Farber Cancer Institute) B Binita Shah (Department of Cancer Biology, Dana-Farber Cancer Institute) M Michael Darnowski (Department of Cancer Biology, Dana-Farber Cancer Institute) M Mia Chung (Department of Cancer Biology, Dana-Farber Cancer Institute) W Wei Pin Teh (Department of Cancer Biology, Dana-Farber Cancer Institute) J Jianwei Che (Department of Cancer Biology, Dana-Farber Cancer Institute) I Irina Bezsonova S Sara J. Buhrlage (Department of Cancer Biology, Dana-Farber Cancer Institute)

Abstract

Ubiquitin-specific protease 7 (USP7) is a deubiquitylase essential for cell homeostasis, DNA repair, and regulation of both tumor suppressors and oncogenes. Recently, haploinsufficiency of USP7 has been associated with Hao–Fountain syndrome (HAFOUS), a rare neurodevelopmental disorder. Although a range of USP7 inhibitors have been developed over the last decade, in the context of HAFOUS, USP7 activators may represent a more relevant approach. To address this challenge, we report the identification and characterization of a small-molecule activator of USP7 called MS-8. Structural and functional studies show that MS-8 allosterically activates USP7, mimicking the endogenous autoactivation mechanism of the enzyme. We observed that MS-8 engages and activates mutant USP7 in a cellular context, impacting downstream proteins. Taken together, our study provides validation of the USP7 activator that paves the way toward activation-driven USP7 pharmacology.

Article Details

Volume / Issue Vol. 122, Issue 42
Published October 21, 2025
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (14)

I

Isabella Jaen Maisonet

Department of Cancer Biology, Dana-Farber Cancer Institute

M

Mona Sharafi

Department of Cancer Biology, Dana-Farber Cancer Institute

E

Emilie J. Korchak

Department of Molecular Biology and Biophysics, University of Connecticut

A

Andres Salazar-Chaparro

Department of Cancer Biology, Dana-Farber Cancer Institute

A

Ariana S. Bratt

Department of Cancer Biology, Dana-Farber Cancer Institute

T

Tvesha Parikh

Department of Molecular Biology and Biophysics, University of Connecticut

A

Anthony C. Varca

Department of Cancer Biology, Dana-Farber Cancer Institute

B

Binita Shah

Department of Cancer Biology, Dana-Farber Cancer Institute

M

Michael Darnowski

Department of Cancer Biology, Dana-Farber Cancer Institute

M

Mia Chung

Department of Cancer Biology, Dana-Farber Cancer Institute

W

Wei Pin Teh

Department of Cancer Biology, Dana-Farber Cancer Institute

J

Jianwei Che

Department of Cancer Biology, Dana-Farber Cancer Institute

I

Irina Bezsonova

S

Sara J. Buhrlage

Department of Cancer Biology, Dana-Farber Cancer Institute