9vng
Small GTPase RhoA Y42C mutant in complex with covalent inhibitor
Structural highlights
FunctionRHOA_HUMAN Regulates a signal transduction pathway linking plasma membrane receptors to the assembly of focal adhesions and actin stress fibers. Involved in a microtubule-dependent signal that is required for the myosin contractile ring formation during cell cycle cytokinesis. Plays an essential role in cleavage furrow formation. Required for the apical junction formation of keratinocyte cell-cell adhesion. Serves as a target for the yopT cysteine peptidase from Yersinia pestis, vector of the plague, and Yersinia pseudotuberculosis, which causes gastrointestinal disorders. Stimulates PKN2 kinase activity. May be an activator of PLCE1. Activated by ARHGEF2, which promotes the exchange of GDP for GTP. Essential for the SPATA13-mediated regulation of cell migration and adhesion assembly and disassembly. The MEMO1-RHOA-DIAPH1 signaling pathway plays an important role in ERBB2-dependent stabilization of microtubules at the cell cortex. It controls the localization of APC and CLASP2 to the cell membrane, via the regulation of GSK3B activity. In turn, membrane-bound APC allows the localization of the MACF1 to the cell membrane, which is required for microtubule capture and stabilization.[1] [2] [3] [4] [5] [6] [7] [8] Publication Abstract from PubMedPathogenic mutations in "undruggable" Ras superfamily proteins challenge drug development by inducing subtle, dynamic conformational changes. Here, we integrated X-ray crystallography with native mass spectrometry and ultraviolet photodissociation (nMS-UVPD) to reveal a cryptic conformation in the oncogenic Y42C mutant of RhoA. While crystallography alone resolved two ambiguous structures, nMS-UVPD determined the dominant conformation by directly mapping the mutant's conformational dynamics, identifying an enhanced Mg(2+)-locked conformation. We explored the mechanism of mutation impairing GTP hydrolysis. This state unmasks a previously hidden, druggable pocket adjacent to Cys42, guiding our identification of a covalent inhibitor. Our integrated approach establishes a roadmap for targeting pathogenic protein mutants previously considered "undruggable" due to their highly dynamic nature. Discovering Targetable Conformation of RhoA Mutant by Integrating Native Mass Spectrometry, Ultraviolet Photodissociation, and X-ray Diffraction.,Wu H, Liu Z, Jiang H, Zhao H, Dong C, Lu Y, Zu S, Guo Y, Lai C, Luo P, Xu K, Yang Y, Yang Y, Sun Z, Huang Q, Xiong H, Zhou L, Luo Y, Zeng Y, Du D, Liang Z, Xiao W, Zhao S, Zhang W, Tang Y, Xiao C, Chen K, Yang X, Wang F, Luo C J Am Chem Soc. 2026 Mar 25;148(11):11709-11718. doi: 10.1021/jacs.5c20067. Epub , 2026 Mar 16. PMID:41837560[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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