Structure-based discovery of first inhibitors targeting the helicase activity of human PIF1

DOI: 10.1093/nar/gkae897

Authors: Mark j. A. Wever (Edelris; Univ. Grenoble Alpes, CNRS, DCM) , Francesca r. Scommegna (University of Sheffield) , Sara Egea-Rodriguez (Ludwig-Maximilians-Universität (LMU) Munich & German Cancer Consortium (DKTK); University Duisburg-Essen) , Saba Dehghani-Tafti (University of Sheffield) , Jose Brandao-Neto (Diamond Light Source) , Jean-François Poisson (Univ. Grenoble Alpes, CNRS, DCM) , Iris Helfrich (Ludwig-Maximilians-Universität (LMU) Munich & German Cancer Consortium (DKTK); University Duisburg-Essen) , Alfred A. Antson (University of York) , Vincent Rodeschini (Edelris) , Ben Bax (University of York; Cardiff University) , Didier Roche (Edelris) , Cyril M. Sanders (University of Sheffield)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nucleic Acids Research , VOL 54

State: Published (Approved)
Published: October 2024
Diamond Proposal Number(s): 19204

Abstract: PIF1 is a conserved helicase and G4 DNA binding and unwinding enzyme, with roles in genome stability. Human PIF1 (hPIF1) is poorly understood, but its functions can become critical for tumour cell survival during oncogene-driven replication stress. Here we report the discovery, via an X-ray crystallographic fragment screen (XChem), of hPIF1 DNA binding and unwinding inhibitors. A structure was obtained with a 4-phenylthiazol-2-amine fragment bound in a pocket between helicase domains 2A and 2B, with additional contacts to Valine 258 from domain 1A. The compound makes specific interactions, notably through Leucine 548 and Alanine 551, that constrain conformational adjustments between domains 2A and 2B, previously linked to ATP hydrolysis and DNA unwinding. We next synthesized a range of related compounds and characterized their effects on hPIF1 DNA-binding and helicase activity in vitro, expanding the structure activity relationship (SAR) around the initial hit. A systematic analysis of clinical cancer databases is also presented here, supporting the notion that hPIF1 upregulation may represent a specific cancer cell vulnerability. The research demonstrates that hPIF1 is a tractable target through 4-phenylthiazol-2-amine derivatives as inhibitors of its helicase action, setting a foundation for creation of a novel class of anti-cancer therapeutics.

Subject Areas: Biology and Bio-materials, Chemistry, Medicine

Diamond Offline Facilities: XChem
Instruments: NONE-No attached Diamond beamline

Added On: 21/10/2024 19:54

Documents:
gkae897.pdf

Discipline Tags:

Non-Communicable Diseases Health & Wellbeing Cancer Biochemistry Chemistry Structural biology Drug Discovery Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX) Fragment Screening