Cell Reports
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2020
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IF 8.109
Lidia Wrobel,Farah H. Siddiqi,Sandra M. Hill,Sung Min Son,Cansu Karabiyik,Hyunjeong Kim,David C. Rubinsztein
Summary The mechanistic target of rapamycin complex 2 (mTORC2) controls cell metabolism and survival in response to environmental inputs. Dysregulation of mTORC2 signaling has been linked to diverse human diseases, including cancer and metabolic disorders, highlighting the importance of a tightly controlled mTORC2. While mTORC2 assembly is a critical determinant of its activity, the factors regulating this event are not well understood, and it is unclear whether this process is regulated by growth factors. Here, we present data, from human cell lines and mice, describing a mechanism by which growth factors regulate ubiquitin-specific protease 9X (USP9X) deubiquitinase to stimulate mTORC2 assembly and activity. USP9X removes Lys63-linked ubiquitin from RICTOR to promote its interaction with mTOR, thereby facilitating mTORC2 signaling. As mTORC2 is central for cellular homeostasis, understanding the mechanisms regulating mTORC2 activation toward its downstream targets is vital for our understanding of physiological processes and for developing new therapeutic strategies in pathology.
研究领域:
细胞生物学
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分子生物学
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癌症研究
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代谢研究
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DOI
PubMed
高影响因子
RENAL FAILURE
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2025
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IF 3
Ningjun Shao,Kedan Cai,Yue Hong,Lingping Wu,Qun Luo
Nuclear factor erythroid 2-related factor 2 (Nrf2) regulates many critical genes associated with iron storage and transportation, the activity of which is influenced by E3 ligase-mediated ubiquitination. We wondered whether there is a deubiquitinase that mediates the deubiquitination of Nrf2 to stabilize Nrf2 expression and further prevent diabetic kidney disease (DKD). High glucose (HG) was applied to induce an in vitro model of DKD. The effects of HG on HK-2 cell viability, apoptosis, Fe2+ level, Nrf2, and ubiquitin-specific protease 9X (USP9X) were assessed by cell counting kit-8 (CCK-8) assay, flow cytometry, iron assay, and Western blot. The direct interaction between Nrf2 and USP9X was analyzed using co-immunoprecipitation and ubiquitination assay. After transfection and ferrostatin-1 (Fer-1) intervention, Nrf2 and USP9X levels, cell viability, apoptosis, and Fe2+ level were tested again. Reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH) contents, and ferroptosis-related markers were assessed by ROS assay kit, ELISA, and Western blot. HG reduced cell viability and levels of USP9X and Nrf2, while elevating apoptosis and Fe2+ level. An interaction between USP9X and Nrf2 has been verified and USP9X deubiquitinated Nrf2. Nrf2 up-regulation augmented the viability, GSH content, and ferroptosis-related protein expressions, while suppressing the apoptosis, Fe2+ level, MDA, and ROS content in HG-mediated HK-2 cells, which was reversed by USP9X silencing. Fer-1 offset the combined modulation of Nrf2 and siUSP9X on HG-induced HK-2 cells. USP9X mediates Nrf2 deubiquitinase to hamper the ferroptosis in DKD in vitro.
研究领域:
分子生物学
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肾脏病学
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产品关联
DOI
PubMed
高影响因子
LIFE SCIENCES
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2026
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IF 6.4
Fengzhen Huang,Jiping Yi,Tieqiao Zhou,Jibao Wu,Xiaojing Li,Heng Meng,Xiaoxiang Gong
Background YTHDF3 expression is up-regulated in sepsis-associated encephalopathy (SAE), yet its precise function remains to be fully elucidated. This study aims to investigate the role of YTHDF3 in microglial pyroptosis during SAE and to explore its upstream and downstream regulatory mechanisms. Methods Lipopolysaccharide (LPS) induced SAE models were established in mice and primary microglia for the assessment of YTHDF3 and pyroptosis levels. Downstream targets of YTHDF3 were identified through RNA sequencing and RNA immunoprecipitation. Ultimately, chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR) was utilized to confirm H3K18la enrichment at the YTHDF3 promoter. Results In both in vitro and in vivo models of SAE, YTHDF3 expression was significantly upregulated. Crucially, YTHDF3 knockdown effectively attenuated NLRP3-mediated microglial pyroptosis, thereby alleviating neuroinflammation and restoring cognitive function in SAE mice. Mechanistically, Usp9x acted as a direct downstream target of YTHDF3 to mediate the deubiquitination of NLRP3, which in turn augmented microglial pyroptosis in SAE. Furthermore, the transcriptional upregulation of YTHDF3 was promoted by H3K18la enrichment at its promoter. Inhibition of the lactylation-driven YTHDF3/Usp9x/NLRP3 signaling axis attenuates microglial pyroptosis and ameliorates cognitive dysfunction in SAE models. Conclusion Lactylation-driven YTHDF3 promotes microglial pyroptosis and cognitive impairment in SAE by targeting the Usp9x/NLRP3 axis. Our findings highlight this axis as a potential therapeutic target for SAE. Download: Download high-res image (123KB) Download: Download full-size image
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DOI
高影响因子
JOURNAL OF PROTEOME RESEARCH
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2026
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IF 3.8
Chen Xiangling,Huang Nan,Xu Zhihan,Luo Juan,Dong Qiongye,Lyu Zhaojie
Clear cell renal
cell carcinoma (ccRCC) is the predominant
histological
subtype of kidney cancer, characterized by a paucity of therapeutic
targets and a dismal prognosis in advanced stages. Although family
with sequence similarity 49 member B (FAM49B) has been implicated
in tumor progression with context-dependent roles, its function in
ccRCC remains undefined. Herein, we elucidated the expression profile
and regulatory mechanisms of FAM49B by utilizing integrated bioinformatics,
molecular biology, and proteomic approaches. Analysis of TCGA and
CPTAC data sets revealed a significantly upregulated FAM49B protein
in ccRCC tissues that positively correlated with pathological grade,
while the mRNA level was unchanged. Mechanistically, FAM49B undergoes
proteasomal degradation, whereas the deubiquitinating enzyme USP9X
directly binds to and stabilizes FAM49B. Pharmacological inhibition
or knockdown of USP9X notably reduces FAM49B protein abundance without
altering its transcription. Quantitative proteomic and affinity mass
spectrometry identified ATP1B1 as a critical downstream effector of
FAM49B. Western blotting (WB) analysis verified that silencing FAM49B
downregulated ATP1B1 in ccRCC cells, while coimmunoprecipitation assays
established their direct physical interaction. Consistent with FAM49B
expression profiles, ATP1B1 protein levels were elevated in high-grade
ccRCC specimens. Collectively, these findings delineate a USP9X–FAM49B–ATP1B1
signaling axis that drives ccRCC progression, representing a promising
diagnostic biomarker and potential therapeutic target.
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DOI
PubMed
高影响因子
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