Stabilization of interdomain closure by a G protein inhibitor

• 成果类型: Article
• 署名作者: Todd, Tyson D.; Vithani, Neha; Singh, Sukrit; Bowman, Gregory R.; Blumer, Kendall J.; Soranno, Andrea
• 署名单位: Washington University (WUSTL); Washington University (WUSTL); University of Pennsylvania; Washington University (WUSTL)
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-13910
• DOI: 10.1073/pnas.2311711121
• 发表日期: 2024-09-03
• 关键词: guanine-nucleotide-binding; cyclic depsipeptide; crystal-structure; structural basis; DYNAMICS; alpha; mechanisms; ym-254890; insights; gdp

摘要

Inhibitors of heterotrimeric G proteins are being developed as therapeutic agents. Epitomizing this approach are YM-254890 (YM) and FR900359 (FR), which are efficacious in models of thrombosis, hypertension, obesity, asthma, uveal melanoma, and pain, and under investigation as an FR- antibody conjugate in uveal melanoma clinical trials. YM/FR inhibits the Gq/11/14 subfamily by interfering with GDP (guanosine diphosphate) release, but by an unknown biophysical mechanism. Here, we show that YM inhibits GDP release by stabilizing closure between the Ras- like and alpha- helical domains of a G alpha subunit. Nucleotide- free G alpha adopts an ensemble of open and closed configurations, as indicated by single- molecule F & ouml;rster resonance energy transfer and molecular dynamics simulations, whereas GDP and GTP gamma S (guanosine 5'- O- [gamma- thio]triphosphate) stabilize distinct closed configurations. YM stabilizes closure in the presence or absence of GDP without requiring an intact interdomain interface. All three classes of mammalian G alpha subunits that are insensitive to YM/FR possess homologous but degenerate YM/ FR binding sites, yet can be inhibited upon transplantation of the YM/FR binding site of Gq. Novel YM/FR analogs tailored to each class of G protein will provide powerful new tools for therapeutic investigation.