RAS mutations are found in 30% of all human cancers, with KRAS the most frequently mutated among the three RAS isoforms (KRAS, NRAS, and HRAS). However, directly targeting oncogenic KRAS with small molecules in the nucleotide-binding site has been difficult because of the high affinity of KRAS for GDP and GTP. We designed an engineered allele of KRAS and a covalent inhibitor that competes for GTP and GDP. This ligand-receptor combination demonstrates that the high affinity of GTP and GDP for RAS proteins can be overcome with a covalent inhibitor and a suitably engineered binding site. The covalent inhibitor irreversibly modifies the protein at the engineered nucleotide-binding site and is able to compete with GDP and GTP. This provides a new tool for studying KRAS function and suggests strategies for targeting the nucleotide-binding site of oncogenic RAS proteins.
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http://dx.doi.org/10.1021/acs.biochem.7b01113 | DOI Listing |
Biochim Biophys Acta Bioenerg
January 2025
Department of Molecular Biosciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kita-ku, Kyoto 603-8555, Japan. Electronic address:
The F domain of FF-ATP synthases/ATPases (FF) possesses three catalytic sites on the three αβ interfaces, termed αβ, αβ, and αβ, located mainly on the β subunits. The enzyme also has three non-catalytic ATP-binding sites on the three αβ interfaces, located mainly on the α subunits. When ATP does not bind to the non-catalytic site, FF becomes significantly prone to ADP inhibition, ultimately resulting in the loss of ATPase activity.
View Article and Find Full Text PDFJ Trace Elem Med Biol
January 2025
Department of Pathology, College of Medicine, King Khalid University, Asir 61421, Saudi Arabia; Department of Forensic Medicine and Clinical Toxicology, Mansoura University, Egypt.
Background: Vanadium (VAN) is a significant trace element, but its higher exposure is reported to cause severe organ toxicity. Tectochrysin (TEC) is a naturally derived flavonoid which demonstrates a wide range of pharmacological properties.
Aim: The current study was planned to assess the cardioprotective potential of TEC against VAN induced cardiotoxicity in rats via regulating biochemical, and histological profile.
Nat Commun
January 2025
Laboratory of Membrane Biology and Biophysics, The Rockefeller University, New York, NY, USA.
Multidrug resistance-associated protein 2 (MRP2) is an ATP-powered exporter important for maintaining liver homeostasis and a potential contributor to chemotherapeutic resistance. Using cryogenic electron microscopy (cryo-EM), we determine the structures of human MRP2 in three conformational states: an autoinhibited state, a substrate-bound pre-translocation state, and an ATP-bound post-translocation state. In the autoinhibited state, the cytosolic regulatory (R) domain plugs into the transmembrane substrate-binding site and extends into the cytosol to form a composite ATP-binding site at the surface of nucleotide-binding domain 2.
View Article and Find Full Text PDFJ Biomol Struct Dyn
January 2025
Department of Studies in Physics, University of Mysore, Mysuru, India.
Sci Adv
January 2025
Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
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