Skip NavigationSkip to Content
Return Return to Search Results

Blocking C-terminal processing of KRAS4b via a direct covalent attack on the CaaX-box cysteine

  1. Author:
    Maciag,Anna [ORCID]
    Yang, Yue
    Sharma,Alok [ORCID]
    Turner,David
    Dehart,Caroline
    Abdelkarim, Hazem
    Fan,Lixin
    Smith,Brian
    Kumari,Vandana
    Dyba,Marcin
    Rigby,Megan
    Castillo Badillo,Jean
    Adams, Lauren
    Fornelli, Luca [ORCID]
    Fox, Stephen
    Brafman, Alla
    Turbyville,Thomas
    Gillette,William [ORCID]
    Messing,Simon [ORCID]
    Agamasu, Constance
    Wolfe, Andrew L
    Gysin, Stephan
    Chan, Albert H [ORCID]
    Simanshu,Dhirendra [ORCID]
    Esposito,Dominic [ORCID]
    Chertov,Oleg [ORCID]
    Stephen,Andrew [ORCID]
    Arkin, Michelle [ORCID]
    Renslo, Adam [ORCID]
    Kelleher, Neil L [ORCID]
    Gaponenko, Vadim
    Lightstone, Felice C
    Nissley,Dwight [ORCID]
    McCormick, Frank [ORCID]

  2. Author Address

    National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21701., Lawrence Livermore National Laboratory, Physical and Life Sciences Directorate, Biotechnology and Biosciences Division, Livermore, CA 94550., Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60607., Basic Science Program, Frederick National Laboratory for Cancer Research, Small-Angle X-ray Scattering Facility of the National Cancer Institute, Frederick, MD 21702., Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208., Department of Chemistry, Proteomics Center of Excellence, Northwestern University, Evanston, IL 60208., Department of Cellular and Molecular Pharmacology, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA 94158., Department of Pharmaceutical Chemistry, Small Molecule Discovery Center, University of California, San Francisco, CA 94143., Departments of Chemical and Biological Engineering, Chemistry, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, Evanston, IL 60208.,
    1. Year: 2025
    2. Date: May 13
    3. Epub Date: 2025 05 09
  2. Journal: Proceedings of the National Academy of Sciences of the United States of America
    1. 122
    2. 19
    3. Pages: e2410766122
  4. Type of Article: Article
  5. Article Number: e2410766122
  1. Abstract:

    RAS is the most frequently mutated oncogene in cancer. RAS proteins show high sequence similarities in their G-domains but are significantly different in their C-terminal hypervariable regions (HVR). These regions interact with the cell membrane via lipid anchors that result from posttranslational modifications (PTM) of cysteine residues. KRAS4b is unique as it has only one cysteine that undergoes PTM, C185. Small molecule covalent modification of C185 would block any form of prenylation and subsequently inhibit attachment of KRAS4b to the cell membrane, blocking its biological activity. We translated this concept to the discovery and development of disulfide tethering screen hits into irreversible covalent modifiers of C185. These compounds inhibited proliferation of KRAS4b-driven mouse embryonic fibroblasts, but not cells driven by N-myristoylated KRAS4b that harbor a C185S mutation and are not dependent on C185 prenylation. Top-down proteomics was used to confirm target engagement in cells. These compounds bind in a pocket formed when the HVR folds back between helix 3 and 4 in the G-domain (HVR-a3-a4). This interaction can happen in the absence of small molecules as predicted by molecular dynamics simulations and is stabilized in the presence of C185 binders as confirmed by small-angle X-ray scattering and solution NMR. NOESY-HSQC, an NMR approach that measures internuclear distances of 6 197; or less, and structure analysis identified the critical residues and interactions that define the HVR-a3-a4 pocket. Further development of compounds that bind to this pocket could be the basis of a new approach to targeting KRAS cancers.

    See More

  1. Keywords:

External Sources

  1. View Full Text
  2. DOI: 10.1073/pnas.2410766122
  3. PMID: 40343987

Library Notes

  1. Fiscal Year: FY2024-2025
NCI at Frederick

You are leaving a government website.

This external link provides additional information that is consistent with the intended purpose of this site. The government cannot attest to the accuracy of a non-federal site.

Linking to a non-federal site does not constitute an endorsement by this institution or any of its employees of the sponsors or the information and products presented on the site. You will be subject to the destination site's privacy policy when you follow the link.

ContinueCancel