CELLULAR AND MOLECULAR LIFE SCIENCES
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2023
·Vol. 80
·期 4
·1-22
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IF 8
Xu Rongmei,Wan Min,Shi Xuemeng,Ma Shumin,Zhang Lina,Yi Ping,Zhang Rongying
Membrane trafficking processes regulate the G protein-coupled receptor activity. The muscarinic acetylcholine receptors (mAChRs) are highly pursued drug targets for neurological diseases, but the cellular machineries that control the trafficking of these receptors remain largely elusive. Here, we revealed the role of the small GTPase Rab10 as a negative regulator for the post-activation trafficking of M4 mAChR and the underlying mechanism. We show that constitutively active Rab10 arrests the receptor within Rab5-positive early endosomes and significantly hinders the resensitization of M4-mediated Ca 2+ signaling. Mechanistically, M4 binds to Rab10-GTP, which requires the motif 386 RKKRQMAA 393 (R 386 -A 393 ) within the third intracellular loop. Moreover, Rab10-GTP inactivates Arf6 by recruiting the Arf6 GTPase-activating protein, ACAP1. Strikingly, deletion of the motif R 386 -A 393 causes M4 to bypass the control by Rab10 and switch to the Rab4-facilitated fast recycling pathway, thus reusing the receptor. Therefore, Rab10 couples the cargo sorting and membrane trafficking regulation through cycle between GTP-bound and GDP-bound state. Our findings suggest a model that Rab10 binds to the M4 like a molecular brake and controls the receptor’s transport through endosomes, thus modulating the signaling, and this regulation is specific among the mAChR subtypes.
研究领域:
细胞生物学
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神经科学
·
药理学
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产品关联
DOI
PubMed
高影响因子
Cancer Medicine
·
2025
·Vol. 14
·期 9
·e70872
·
IF 3.1
Haitao Xu,Dangui Chen,Jia Lu,Long Zhong,Lihong Wang,Jian Ge
Background Acute myeloid leukemia (AML) represents a highly aggressive hematological malignancy characterized by a poor prognosis and a pressing demand for innovative diagnostic and prognostic biomarkers. Recent studies have indicated that ADP-ribosylation factor 6 (ARF6) is overexpressed across various cancer types; however, its specific role and implications in AML have yet to be thoroughly investigated. Methods To elucidate the clinical relevance and functional mechanisms of ARF6 in AML, we conducted an integrated analysis utilizing RNA sequencing data from The Cancer Genome Atlas (TCGA) alongside clinical samples and AML cell lines. The diagnostic potential of ARF6 was assessed through receiver operating characteristic curve analysis, and logistic regression was employed to identify factors correlating with elevated ARF6 expression. Functional assays were performed to elucidate the effects of ARF6 modulation on apoptosis, cell cycle progression, and AML cell proliferation, while mechanistic investigations focused on the PI3K/AKT/mTOR signaling pathway, particularly in the context of pharmacological PI3K inhibition. Results Our findings revealed a significant upregulation of ARF6 in AML compared to normal controls, with diagnostic efficacy indicated by an AUC of 0.793. Logistic regression analysis identified older age (> 60 years) and a higher white blood cell count (> 20 × 10 9 /L) as significant predictors of high ARF6 expression. Moreover, elevated ARF6 levels were independently associated with shorter overall survival (HR = 1.634, p = 0.045). Notably, ARF6 knockdown induced apoptosis and G0/G1 cell cycle arrest, whereas its overexpression yielded contrary effects. In addition, ARF6 activated the PI3K/AKT/mTOR pathway, which was abrogated by pharmacological PI3K inhibition. Conclusion Collectively, our findings establish ARF6 as a valuable diagnostic and prognostic marker in AML, driving disease progression through the activation of the PI3K/AKT/mTOR pathway. These insights not only enhance our understanding of AML pathology but also underscore the potential of targeting ARF6 for therapeutic intervention in AML treatment paradigms. Future research should aim at evaluating the therapeutic implications of targeting ARF6 in combination with existing treatment modalities.
研究领域:
血液学
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肿瘤学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
Nano Today
·
2023
·
IF 17.4
Siyang Song,Xiangfu Guo,Zibin Zhang,Shumin Fan,Runyu Zhang,Zhicheng Yan,Qing Chen,Yang Song,Peiyao Wu,Chunling Wang,Yuxi Cheng,Lan Yuan,Hua Zhang,Wenbing Dai,Xueqing Wang,Bing He,Qiang Zhang
Intracellular delivery crossing the endomembrane barrier is the “last mile to target” for nano delivery systems carrying biomacromolecules, including genetic medicines . Nevertheless, a mass of nanomedicines is currently restricted by their equivocal safety and delivery efficiency. Here, we establish a universal strategy independent of nanomaterials . Such a policy broadly facilitates the intracellular delivery of all kinds of tested nanomedicines, subtly by inducing ARF6 GTPases to their overactivated GTP-bound state. ARF6, one member of ARF subfamily in small GTPases , is verified to regulate intracellular vesicle transport and lipid metabolism through GTP/GDP conversion. ARF6 biased to GTP-bound state causes the increased endocytosis and reduced exocytosis of eleven types of nanoparticles . This universal effect is derived from the formation of a hybrid type of endosomes triggered by overactivated ARF6 via regulating cholesterol-associated vesicles and lipid raft/caveolae pathways. Due to the mild microenvironment in hybrid endosomes, the internalized protein and nanoparticles are steadily delivered to the cytoplasm, avoiding the intensive degradation in lysosomes . Based on these findings, we identify QS11, a safe small molecule inhibitor of ARF GTPase-activating proteins, significantly enhances the antitumor efficacy of siEGFR-loaded nanoparticles by inducing ARF6 overactivation. In sum, these findings reveal that the tactics of tuning ARF6 GTPases to GTP-bound form will widely benefit cellular nano delivery.
研究领域:
药理学
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纳米技术
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细胞生物学
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分子生物学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）