Endosomal function is essential for pattern recognition receptor signaling, through endosomal Toll-like receptor (TLR) sensing of nonself RNA and DNA. The specific interaction of the calcium sensor Munc13-4 with syntaxin 7 (STX7) regulates endosomal flux and Munc13-4 depletion decreases the systemic inflammatory response to unmethylated DNA. Using high-throughput screening and orthogonal cell-based validation, we identified small-molecule inhibitors of the Munc13-4-STX7 interaction, ENDOtollins (ENDOs). ENDOs inhibit extracellular signal-regulated kinase signaling in neutrophils and interferon (IFN) regulatory factor signaling in plasmacytoid dendritic cells (DCs) in response to endosomal TLR ligands but not to plasma membrane agonists, highlighting specificity for the endocytic pathway. Mechanistically, ENDOs inhibit endolysosomal flux and decrease endolysosomal cargo degradation. Chemical optimization identified ENDO12 as the most potent inhibitor. ENDO12 inhibited primary DC responses to TLR3, TLR7 and TLR9 and reduced CpG-induced systemic inflammation, manifested as decreased levels of the proinflammatory mediators myeloperoxidase, interleukin 6 and IFNγ. Our findings have significant implications for immunodeficiency, inflammation and innate immunity.
© 2026. The Author(s).

Protein homeostasis is tightly controlled by the coordinated actions of E3 ubiquitin ligases and deubiquitinases (DUBs). We previously identified Spindlin-4 (SPIN4), a histone H3K4me3 reader, as a degradation substrate of DCAF16. In this study, we confirmed this degradation pathway using an E3 ligase-focused CRISPR-Cas9 knockout screen. Furthermore, through a DUB-focused CRISPR-Cas9 knockout screen and biochemical analyses, we demonstrated that the deubiquitinase BAP1 interacts with and stabilizes SPIN4 via its deubiquitination activity. Inhibition or loss of BAP1 reduces SPIN4 levels, highlighting its critical role in maintaining SPIN4 homeostasis. Proteomics and interactome analyses further support this regulatory axis. These findings reveal a dynamic balance controlling SPIN4 stability, with potential implications for epigenetic regulation and disease processes.

Lactate is a vital metabolite in cancer, significantly impacting tumor progression, metastasis, and overall survival. The CD147-monocarboxylate transporter 1 (MCT1) complex, a major lactate transporter, has emerged as a promising therapeutic target. However, no effective protein-protein interaction (PPI) inhibitors targeting the CD147-MCT1 complex have been identified. In this study, we found that the small-molecule inhibitor crizotinib effectively disrupts the CD147-MCT1 interaction, leading to reduced lactate secretion from melanoma cells and decreased lactate uptake by macrophages. In vivo studies demonstrated that crizotinib treatment significantly suppressed tumor growth and enhanced responsiveness to immune checkpoint blockade therapy. Flow cytometry revealed that this metabolic intervention inhibits M2 polarization and reshapes the tumor immune microenvironment. Transcriptomic analysis further revealed that lactate induces C-X-C motif chemokine ligand 13 (CXCL13) expression in macrophages, which enhances melanoma invasiveness and impairs immune cell-mediated cytotoxicity. Importantly, crizotinib suppresses CXCL13 expression by blocking lactate-driven histone lactylation, thereby reversing the transcriptional reprogramming induced by lactate, as evidenced by reduced histone H3 lysine 18 lactylation (H3K18la) enrichment at the CXCL13 promoter. Taken together, these findings provide new insights into targeting metabolic-immune crosstalk and highlight the value of disrupting CD147-MCT1 interactions to improve immunotherapeutic responses in patients with melanoma.
© 2025 The Author(s). MedComm published by Sichuan International Medical Exchange & Promotion Association (SCIMEA) and John Wiley & Sons Australia, Ltd.

New research builds on previous findings that JMJD8 mediates insulin resistance by promoting adipocyte hypertrophy. We identified PLIN2 as a binding partner of JMJD8 using proteomics approaches. This study reveals a physical interaction between JMJD8 and PLIN2, which plays a crucial role in driving adipocyte hypertrophy and insulin resistance. JMJD8 suppresses fasting-induced lipophagy and reduces energy production by inhibiting PLIN2 phosphorylation. These findings highlight the importance of JMJD8 and PLIN2 in regulating lipid droplet homeostasis and suggest a potential mechanism for controlling fat mobilization during energy deprivation.
© 2025 by the American Diabetes Association.

Neo-protein-protein interactions (neoPPI) induced by mutated amino acid residues present a promising class of therapeutic targets for proximity pharmacology-enabled drug discovery. Small molecule compounds, such as cyclosporin and FK506, have the capability to mimic the mutational effect to create new interaction interfaces to enhance the interaction of a protein with an unrelated, or low affinity protein. Such small molecules can function as molecular glues to purposefully generate neoPPIs for physiological reprogramming and therapeutic intervention. Thus, an unbiased approach for the systematic discovery of neoPPI-inducing compounds is much needed to accelerate the proximity pharmacology field. With the demonstrated small molecule induced neoPPI of oncogenic KRAS with cyclophilin A (CYPA), here we report the development of a robust cell lysate-based time-resolved fluorescence resonance energy transfer (TR-FRET) assay to characterize KRAS-CYPA neoPPI inducing molecular glues. We show that the developed TR-FRET assay can monitor the induced interaction of CYPA with oncogenic KRAS variants, KRAS-G12C, G12D and G12V. The assay was optimized to achieve a robust performance in a miniaturized format, which was utilized to demonstrate the potent effect of RMC-7977, a known molecular glue, in inducing the KRAS-CYPA interaction. This validated assay platform allows for the characterization of molecular glue-induced KRAS-CYPA neoPPI, which is readily applicable to explore the vast chemical space for the discovery of novel KRAS-CYPA neoPPI inducers and can be generally applicable for unbiased discovery of proximity-inducing molecular glues.