Abstract
Inhibiting the RAS oncogenic protein has largely been through targeting the switch regions that interact with signalling effector proteins. Here, we report designed ankyrin repeat proteins (DARPins) macromolecules that specifically inhibit the KRAS isoform by binding to an allosteric site encompassing the region around KRAS-specific residue histidine 95 at the helix α3/loop 7/helix α4 interface. We show that these DARPins specifically inhibit KRAS/effector interactions and the dependent downstream signalling pathways in cancer cells. Binding by the DARPins at that region influences KRAS/effector interactions in different ways, including KRAS nucleotide exchange and inhibiting KRAS dimerization at the plasma membrane. These results highlight the importance of targeting the α3/loop 7/α4 interface, a previously untargeted site in RAS, for specifically inhibiting KRAS function.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Allosteric Site / drug effects*
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Ankyrin Repeat
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Antineoplastic Agents / pharmacology*
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Antineoplastic Agents / therapeutic use
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Cell Line, Tumor
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Cell Membrane / drug effects
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Cell Membrane / metabolism
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Drug Design*
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Drug Screening Assays, Antitumor
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HEK293 Cells
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Histidine / metabolism
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Humans
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Isoenzymes / antagonists & inhibitors
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Isoenzymes / genetics
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Isoenzymes / metabolism
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Neoplasms / drug therapy*
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Neoplasms / genetics
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Neoplasms / pathology
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Peptide Library
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Protein Binding / drug effects
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Protein Binding / genetics
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Protein Multimerization / drug effects
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Proto-Oncogene Proteins p21(ras) / antagonists & inhibitors*
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Proto-Oncogene Proteins p21(ras) / genetics
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Proto-Oncogene Proteins p21(ras) / metabolism
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Signal Transduction / drug effects
Substances
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Antineoplastic Agents
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Isoenzymes
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KRAS protein, human
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Peptide Library
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Histidine
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Proto-Oncogene Proteins p21(ras)