RT Journal Article
SR Electronic
T1 Structure-guided bifunctional molecules hit a DEUBAD-lacking hRpn13 species upregulated in multiple myeloma
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.07.16.452547
DO 10.1101/2021.07.16.452547
A1 Xiuxiu Lu
A1 Venkata R. Sabbasani
A1 Vasty Osei-Amponsa
A1 Christine N. Evans
A1 Julianna C. King
A1 Sergey G. Tarasov
A1 Marzena Dyba
A1 King C. Chan
A1 Charles D. Schwieters
A1 Sulbha Choudhari
A1 Caroline Fromont
A1 Yongmei Zhao
A1 Bao Tran
A1 Xiang Chen
A1 Hiroshi Matsuo
A1 Thorkell Andresson
A1 Raj Chari
A1 Rolf E. Swenson
A1 Nadya I. Tarasova
A1 Kylie J. Walters
YR 2021
UL http://biorxiv.org/content/early/2021/07/17/2021.07.16.452547.abstract
AB Proteasome substrate receptor hRpn13 is a promising anti-cancer target. By integrated in silico and biophysical screening, we identified a chemical scaffold that binds hRpn13 with non-covalent interactions that mimic the proteasome and a weak electrophile for Michael addition. hRpn13 Pru domain binds proteasomes and ubiquitin whereas its DEUBAD domain binds deubiquitinating enzyme UCHL5. NMR revealed lead compound XL5 to interdigitate into a hydrophobic pocket created by lateral movement of a Pru β-hairpin with an exposed end for Proteolysis Targeting Chimeras (PROTACs). Implementing XL5-PROTACs as chemical probes identified a DEUBAD-lacking hRpn13 species (hRpn13Pru) present naturally with cell type-dependent abundance. XL5-PROTACs preferentially target hRpn13Pru, causing its ubiquitination. Gene-editing and rescue experiments established hRpn13 requirement for XL5-PROTAC-triggered apoptosis and increased p62 levels. These data establish hRpn13 as an anti-cancer target for multiple myeloma and introduce an hRpn13-targeting scaffold that can be optimized for preclinical trials against hRpn13Pru-producing cancer types.Competing Interest StatementThe authors have declared no competing interest.