CELL BIOLOGY INTERNATIONAL
·
2019
·Vol. 43
·期 8
·875-889
·
IF 2.127
Wenjing Li,Zulin Wu,Yongheng Liang
Autophagy is an intracellular degradation process involving many Atg proteins, which are recruited hierarchically to regulate this process. Rab/Ypt GTPases and their activators, guanine nucleotide exchange factors (GEFs), which are critical for regulating vesicle trafficking, are also involved in autophagy. Previously, we reported that yeast Vps21 and its GEF Vps9 are required for autophagy. Later, a third yeast VPS9-domain-containing protein, V A R P- l ike 1 (Vrl1), which was identified as a mutant in major laboratory strains, had partially overlapping functions with Vps9 in trafficking. In this study, we showed that Vrl1 performed roles in autophagy, and its VPS9-domain was crucial for its role in autophagy. We found that localization of Vrl1 differed from the other two VPS9-domain-containing proteins, Vps9 and Muk1, and only Vrl1 changed from multipoint to diffusion after starvation. Like Vps9, Vrl1 suppressed autophagic defects caused by the VPS9 deletion. We further showed that these VPS9-domain-containing proteins, Vps9, Muk1, and Vrl1, all co-localized with Atg8 on autophagosomes in cells blocked in any late step of starvation-induced autophagy, with Vrl1 most often co-localizing with Atg8. A small portion (<25%) of these VPS9-domain-containing proteins were degraded through autophagy. However, a large portion (>60%) of Vrl1 decreased independently of autophagy. We propose that Vrl1 may regulate autophagy in a similar way as Vps9, and the level of Vrl1 partly decreases through both autophagy-dependent and -independent routes.
研究领域:
分子生物学
·
细胞生物学
·
酵母遗传学
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DOI
PubMed
高影响因子
Cell Death & Disease
·
2018
·Vol. 9
·期 10
·1-16
·
IF 5.638
Niu Xiuran,Su Linjia,Qi Shanshan,Gao Zhihui,Zhang Qing,Zhang Sihe
Chaperone-assisted proteasome degradation of oncogenic protein acts as an upstream signal controlling tumorigenesis and progression. The understanding of the co-regulation of chaperone and oncoprotein of endocytosis pathways is extremely limited. In this study, we showed for the first time that proto-Dbl ( dbl proto-oncogene product) is co-enriched with mitochondrial chaperone GRP75 in endocytosis vesicles from ovarian cancer cells. onco-Dbl, produced by oncogenic mutation/degradation of proto-Dbl, markedly enhanced cellular macropinocytosis but suppressed clathrin-mediated endocytosis and clathrin-independent endocytosis pathways, presenting a derailed endocytosis phenotype. GRP75 was associated with proto-Dbl inside cells and modulated Dbl-driven endocytosis derailed by a co-regulatory mode. In spite of not being a component of the Hsc70/Hsp90/proto-Dbl complex, the degradation of proto-Dbl was promoted by GRP75 through the CHIP-mediated ubiquitin–proteasome pathway, of which GRP75 acts as a cooperator with CHIP but also acts as a competitor to Hsc70 and Hsp90 in the multiple chaperones-assisted pro-folding/pro-degradation machinery. Knockdown or inhibition of GRP75 attenuated proto-Dbl degradation and reduced the onco-Dbl level, which differentially impaired Rho GTPases activation and therefore shifted the endocytosis-derailed phenotype. Our data uncovered a novel GRP75-Dbl endocytosis regulatory axis and provided an alternative using chaperone inhibitor to shut down the oncoprotein-driven endocytosis derailment mechanism.
研究领域:
肿瘤学
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细胞生物学
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分子生物学
·
癌症研究
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DOI
PubMed
高影响因子
EMBO REPORTS
·
2025
·
IF 6.2
Shuzhi Cui,Wei Gao,Yuxin Chen,Yi Xu,Zhifang Li,Yu Wei,Yaming Jiu
CDC42 is a member of Rho GTPase family that regulates various biological processes and its activity can be hijacked by invading pathogens. Here, we discovered that the level of active CDC42 in hepatocytes positively correlates with the entry capacity of hepatitis B virus (HBV). Mechanistically, CDC42 activation effectively promotes the transport of the viral receptor sodium taurocholate co-transporting polypeptide (NTCP) to the plasma membrane via Rab11 dependent recycling endosomal pathway. NTCP interacts with Rab11 and activation of CDC42 signaling reinforces the interaction between NTCP and Rab11. We further show that clathrin mediated endocytosis (CME), the known HBV entry pathway, is independent of CDC42 activity. Intriguingly, we reveal that CDC42 dependent macropinocytosis is a route for HBV entry, which is equally essential for viral infection as CME. Together, our findings uncover new mechanisms for HBV entry that involve unrecognized functions of CDC42 and suggest that Rho GTPase signaling might represent a potential target for antiviral therapy.
研究领域:
病毒学
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分子生物学
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细胞生物学
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感染性疾病
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肝脏病学
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信号转导
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药理学
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转化医学
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DOI
PubMed
高影响因子
Cellular & Molecular Immunology
·
2022
·Vol. 19
·期 5
·602-618
·
IF 22.096
Ma Xiaojian,Tan Xi,Yu Bingbing,Sun Wanwei,Wang Heping,Hu Huijun,Du Yanyun,He Ruirui,Gao Ru,Peng Qianwen,Cui Zhihui,Pan Ting,Feng Xiong,Wang Junhan,Xu Chengqi,Zhu Bin,Liu Wei,Wang Chenhui
Fungal infections cause ~1.5 million deaths each year worldwide, and the mortality rate of disseminated candidiasis currently exceeds that of breast cancer and malaria. The major reasons for the high mortality of candidiasis are the limited number of antifungal drugs and the emergence of drug-resistant species. Therefore, a better understanding of antifungal host defense mechanisms is crucial for the development of effective preventive and therapeutic strategies. Here, we report that DOCK2 (dedicator of cytokinesis 2) promotes indispensable antifungal innate immune signaling and proinflammatory gene expression in macrophages. DOCK2-deficient macrophages exhibit decreased RAC GTPase (Rac family small GTPase) activation and ROS (reactive oxygen species) production, which in turn attenuates the killing of intracellular fungi and the activation of downstream signaling pathways. Mechanistically, after fungal stimulation, activated SYK (spleen-associated tyrosine kinase) phosphorylates DOCK2 at tyrosine 985 and 1405, which promotes the recruitment and activation of RAC GTPases and then increases ROS production and downstream signaling activation. Importantly, nanoparticle-mediated delivery of in vitro transcribed (IVT) Rac1 mRNA promotes the activity of Rac1 and helps to eliminate fungal infection in vivo. Taken together, this study not only identifies a critical role of DOCK2 in antifungal immunity via regulation of RAC GTPase activity but also provides proof of concept for the treatment of invasive fungal infections by using IVT mRNA.
研究领域:
免疫学
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微生物学
·
分子生物学
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药理学
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DOI
PubMed
高影响因子
EBioMedicine
·
2024
·
IF 9.7
Harry Cheuk-Hay Lau,Xiang Zhang,Fenfen Ji,Yufeng Lin,Wei Liang,Qing Li,Danyu Chen,Winnie Fong,Xing Kang,Weixin Liu,Eagle Siu-Hong Chu,Queena Wing-Yin Ng,Jun Yu
Abstract
Background: Gut probiotic depletion is associated with non-alcoholic fatty liver disease-associated hepatocellular carcinoma (NAFLD-HCC). Here, we investigated the prophylactic potential of Lactobacillus acidophilus against NAFLD-HCC.
Methods: NAFLD-HCC conventional and germ-free mice were established by diethylnitrosamine (DEN) injection with feeding of high-fat high-cholesterol (HFHC) or choline-deficient high-fat (CDHF) diet. Orthotopic NAFLD-HCC allografts were established by intrahepatic injection of murine HCC cells with HFHC feeding. Metabolomic profiling was performed using liquid chromatography-mass spectrometry. Biological functions of L. acidophilus conditional medium (L.a CM) and metabolites were determined in NAFLD-HCC human cells and mouse organoids.
Findings: L. acidophilus supplementation suppressed NAFLD-HCC formation in HFHC-fed DEN-treated mice. This was confirmed in orthotopic allografts and germ-free tumourigenesis mice. L.a CM inhibited the growth of NAFLD-HCC human cells and mouse organoids. The protective function of L. acidophilus was attributed to its non-protein small molecules. By metabolomic profiling, valeric acid was the top enriched metabolite in L.a CM and its upregulation was verified in liver and portal vein of L. acidophilus-treated mice. The protective function of valeric acid was demonstrated in NAFLD-HCC human cells and mouse organoids. Valeric acid significantly suppressed NAFLD-HCC formation in HFHC-fed DEN-treated mice, accompanied by improved intestinal barrier integrity. This was confirmed in another NAFLD-HCC mouse model induced by CDHF diet and DEN. Mechanistically, valeric acid bound to hepatocytic surface receptor GPR41/43 to inhibit Rho-GTPase pathway, thereby ablating NAFLD-HCC.
Interpretation: L. acidophilus exhibits anti-tumourigenic effect in mice by secreting valeric acid. Probiotic supplementation is a potential prophylactic of NAFLD-HCC.
研究领域:
微生物学
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肝病学
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癌症生物学
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代谢组学
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DOI
PubMed
高影响因子
Frontiers in Plant Science
·
2023
·
IF 5.6
Haihong Chen,Yiyi Hu,Guanpin Yang,Pingping Li,Jingru Yin,Xiaoqing Feng,Qiong Wu,Jingyu Zhang,Baoheng Xiao,Zhenghong Sui
Macropinocytosis is an endocytic process that plays an important role in animal development and disease occurrence but until now has been rarely reported in organisms with cell walls. We investigated the properties of endocytosis in a red alga, Gracilariopsis lemaneiformis . The cells non-selectively internalized extracellular fluid into large-scale endocytic vesicles (1.94 ± 0.51 μm), and this process could be inhibited by 5-(N-ethyl-N-isopropyl) amiloride, an macropinocytosis inhibitor. Moreover, endocytosis was driven by F-actin, which promotes formation of ruffles and cups from the cell surface and facilitates formation of endocytotic vesicles. After vesicle formation, endocytic vesicles could be acidified and acquire digestive function. These results indicated macropinocytosis in G. lemaneiformis . Abundant phosphatidylinositol kinase and small GTPase encoding genes were found in the genome of this alga, while PI3K, Ras, and Rab5, the important participators of traditional macropinocytosis, seem to be lacked. Such findings provide a new insight into endocytosis in organisms with cell walls and facilitate further research into the core regulatory mechanisms and evolution of macropinocytosis.
研究领域:
植物学
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细胞生物学
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分子生物学
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DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2022
·
IF 6.449
Meiling Sun,Zhenghui Luo,Qi Yang,Chunxu Huang,Yu Kuang,Mei Kang,Jie Liu
Methicillin-resistant Staphylococcus aureus (MRSA) has evolved to tolerate almost all known β-lactam antibiotics, and been exhibiting resistance to vancomycin . Developing new drugs against the MRSA infection are urgently needed. Natural resource is enriched with antimicrobial molecules. Here, we report an extract from leaves of Cyclocarya paliurus (ECPL), a species of tree native to China and being traditionally cultivated as medicinal plant , which shows a broad spectrum of bacteriostatic and bactericidal effects at MIC 50 15.99 ± 0.55 μg/ml against methicillin-susceptible and -resistant S. aureus . The ECPL suppresses bacterial expression of FtsZ at both transcriptional and protein levels, inhibits its GTPase activity, blocks the assembly dynamics of FtsZ, and disrupts the formation of Z-ring. The bacteria cells fail to divide, enlarge initially, and lyse eventually. In mouse model, the ECPL facilitates skin wound healing with MRSA infection as effective as vancomycin. Our study unveils the potential of identifying novel molecule in ECPL for development of new class of antibiotic against both methicillin-susceptible and -resistant S. aureus , and support domestication of the C. paliurus growing from wild to cultivated, and further scale up the cultivation into industrialized farm for sustainable harvest for pharmaceutic interest.
研究领域:
微生物学
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药理学
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植物科学
·
传染病学
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DOI
高影响因子
MOLECULAR CELL
·
2023
·
IF 16
Chenchen Xu,Xiaoqing Pan,Dong Wang,Yuanyuan Guan,Wenyu Yang,Xing Chen,Ying Liu
The mechanistic target of rapamycin complex 1 (mTORC1) regulates metabolism and cell growth in response to nutrient levels. Dysregulation of mTORC1 results in a broad spectrum of diseases. Glucose is the primary energy supply of cells, and therefore, glucose levels must be accurately conveyed to mTORC1 through highly responsive signaling mechanisms to control mTORC1 activity. Here, we report that glucose-induced mTORC1 activation is regulated by O-GlcNAcylation of Raptor, a core component of mTORC1, in HEK293T cells. Mechanistically, O-GlcNAcylation of Raptor at threonine 700 facilitates the interactions between Raptor and Rag GTPases and promotes the translocation of mTOR to the lysosomal surface, consequently activating mTORC1. In addition, we show that AMPK-mediated phosphorylation of Raptor suppresses Raptor O-GlcNAcylation and inhibits Raptor-Rags interactions. Our findings reveal an exquisitely controlled mechanism, which suggests how glucose coordinately regulates cellular anabolism and catabolism.
研究领域:
细胞生物学
·
分子生物学
·
代谢
·
信号通路
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DOI
PubMed
高影响因子
JOURNAL OF VIROLOGY
·
2024
·
IF 4
Qiankai Shi,Ran Zhao,Linna Chen,Tianyi Liu,Tao Di,Chunwei Zhang,Zhiying Zhang,Fangfang Wang,Zongxi Han,Junfeng Sun,Shengwang Liu
As an intrinsic cellular mechanism responsible for the internalization of extracellular ligands and membrane components, caveolae-mediated endocytosis (CavME) is also exploited by certain pathogens for endocytic entry [e.g., Newcastle disease virus (NDV) of paramyxovirus]. However, the molecular mechanisms of NDV-induced CavME remain poorly understood. Herein, we demonstrate that sialic acid-containing gangliosides, rather than glycoproteins, were utilized by NDV as receptors to initiate the endocytic entry of NDV into HD11 cells. The binding of NDV to gangliosides induced the activation of a non-receptor tyrosine kinase, Src, leading to the phosphorylation of caveolin-1 (Cav1) and dynamin-2 (Dyn2), which contributed to the endocytic entry of NDV. Moreover, an inoculation of cells with NDV-induced actin cytoskeletal rearrangement through Src to facilitate NDV entry via endocytosis and direct fusion with the plasma membrane. Subsequently, unique members of the Rho GTPases family, RhoA and Cdc42, were activated by NDV in a Src-dependent manner. Further analyses revealed that RhoA and Cdc42 regulated the activities of specific effectors, cofilin and myosin regulatory light chain 2, responsible for actin cytoskeleton rearrangement, through diverse intracellular signaling cascades. Taken together, our results suggest that an inoculation of NDV-induced Src-mediated cellular activation by binding to ganglioside receptors. This process orchestrated NDV endocytic entry by modulating the activities of caveolae-associated Cav1 and Dyn2, as well as specific Rho GTPases and downstream effectors.
研究领域:
病毒学
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细胞生物学
·
分子生物学
·
免疫学
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产品关联
DOI
PubMed
高影响因子
CANCER GENE THERAPY
·
2022
·Vol. 29
·期 12
·1939-1950
·
IF 5.854
Yang Fan,Li Lin,Mu Zhenzhen,Liu Pengyue,Wang Ying,Zhang Yue,Han Xiuping
The nuclear import receptor karyopherin β1 (KPNB1), a member of the Karyopherin protein family, is reported to be overexpressed in various cancers and promote carcinogenesis. By analyzing the correlation between the expression of KPNB1 and the overall survival rate of melanoma patients, we found that melanoma patients with higher expression of KPNB1 had worse survival. Furthermore, the database analyzed that the KPNB1 mRNA level was higher in melanoma samples than that in skin nevus tissues. We thus proposed that KPNB1 played a role in promoting melanoma development, and conducted gain-of- and loss-of-function experiments to test our hypothesis. We found that KPNB1 knockdown significantly retarded the growth and metastasis of melanoma cells in vitro and in vivo, and increased their sensitivity towards the anti-tumor drug cisplatin. KPNB1 overexpression had opposite effects. Notably, in melanoma cells, KPNB1 overexpression significantly decreased Ras-GTPase-activating protein SH3 domain-binding protein 1 (G3BP1) protein level, which was also overexpressed in melanoma samples and enhanced malignant behaviors of melanoma cells. We further demonstrated that KPNB1 overexpression induced deubiquitination of G3BP1, and prevented its degradation. However, KPNB1 overexpression hardly affected the nuclear translocation of G3BP1. Additionally, alterations induced by KPNB1 overexpression were partly reversed by G3BP1 inhibition. Therefore, the results suggest that KPNB1 may promote melanoma progression by stabilizing the G3BP1 protein. KPNB1-G3BP1 axis represents a potential therapeutic targetable node for melanoma.
研究领域:
癌症生物学
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分子生物学
·
细胞生物学
·
肿瘤学
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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
·
纳米技术
·
细胞生物学
·
分子生物学
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产品关联
DOI
高影响因子
RESPIRATORY RESEARCH
·
2023
·Vol. 24
·期 1
·1-14
·
IF 5.8
Liu Jin,Chen Yuqian,Chen Huan,Wang Yan,Li Danyang,Zhang Qianqian,Chai Limin,Qiu Yuanjie,Zhang Jia,Shen Nirui,Wang Qingting,Wang Jian,Li Manxiang
Background Macrophage migration inhibitory factor (MIF) and GTPase dynamin-related protein 1 (Drp1)-dependent aberrant mitochondrial fission are closely linked to the pathogenesis of asthma. However, it is unclear whether Drp1-mediated mitochondrial fission and its downstream targets mediate MIF-induced proliferation of airway smooth muscle cells (ASMCs) in vitro and airway remodeling in chronic asthma models. The present study aims to clarify these issues. Methods In this study, primary cultured ASMCs and ovalbumin (OVA)-induced asthmatic rats were applied. Cell proliferation was detected by CCK-8 and EdU assays. Western blotting was used to detect extracellular signal-regulated kinase (ERK) 1/2, Drp1, autophagy-related markers and E-cadherin protein phosphorylation and expression. Inflammatory cytokines production, airway reactivity test, histological staining and immunohistochemical staining were conducted to evaluate the development of asthma. Transmission electron microscopy was used to observe the mitochondrial ultrastructure. Results In primary cultured ASMCs, MIF increased the phosphorylation level of Drp1 at the Ser616 site through activation of the ERK1/2 signaling pathway, which further activated autophagy and reduced E-cadherin expression, ultimately leading to ASMCs proliferation. In OVA-induced asthmatic rats, MIF inhibitor 4-iodo-6-phenylpyrimidine (4-IPP) treatment, suppression of mitochondrial fission by Mdivi-1 or inhibiting autophagy with chloroquine phosphate (CQ) all attenuated the development of airway remodeling. Conclusions The present study provides novel insights that MIF promotes airway remodeling in asthma by activating autophagy and degradation of E-cadherin via ERK/Drp1 signaling pathway, suggesting that targeting MIF/ERK/Drp1 might have potential therapeutic value for the prevention and treatment of asthma.
研究领域:
免疫学
·
肺科学
·
细胞生物学
·
药理学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）