{"title":"Stromal softness confines pancreatic cancer growth through lysosomal-cathepsin mediated YAP1 degradation.","authors":"Tianci Zhang, Jingjing Chen, Huan Yang, Xiaoyan Sun, Yiran Ou, Qiang Wang, Mouad Edderkaoui, Sujun Zheng, Feng Ren, Ying Tong, Richard Hu, Jiaye Liu, Yun Gao, Stephen J Pandol, Yuan-Ping Han, Xiaofeng Zheng","doi":"10.1007/s00018-024-05466-y","DOIUrl":"10.1007/s00018-024-05466-y","url":null,"abstract":"<p><p>The progression and malignancy of many tumors are associated with increased tissue stiffness. Conversely, the oncogenically transformed cells can be confined in soft stroma. Yet, the underlying mechanisms by which soft matrix confines tumorigenesis and metastasis remain elusive. Here, we show that pancreatic cancer cells are suppressed in the soft extracellular matrix, which is associated with YAP1 degradation through autophagic-lysosomal pathway rather than Hippo signal mediated proteasome pathway. In the soft stroma, PTEN is upregulated and activated, which consequently promotes lysosomal biogenesis, leading to the activation of cysteine-cathepsins for YAP1 degradation. In vitro, purified cathepsin L can directly digest YAP1 under acidic conditions. Lysosomal stress, either caused by chloroquine or overexpression of cystatin A/B, results in YAP1 accumulation and malignant transformation. Likewise, liver fibrosis induced stiffness can promote malignant potential in mice. Clinical data show that down-regulation of lysosomal biogenesis is associated with pancreatic fibrosis and stiffness, YAP1 accumulation, and poor prognosis in PDAC patients. Together, our findings suggest that soft stroma triggers lysosomal flux-mediated YAP1 degradation and induces cancer cell dormancy.</p>","PeriodicalId":10007,"journal":{"name":"Cellular and Molecular Life Sciences","volume":"81 1","pages":"442"},"PeriodicalIF":6.2,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11512982/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142496095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dmitry I Maltsev, Maxim A Solotenkov, Liana F Mukhametshina, Rostislav A Sokolov, Georgy M Solius, David Jappy, Aleksandra S Tsopina, Ilya V Fedotov, Aleksandr A Lanin, Andrei B Fedotov, Viktoriya G Krut', Yulia G Ermakova, Aleksandr A Moshchenko, Andrei Rozov, Aleksei M Zheltikov, Oleg V Podgorny, Vsevolod V Belousov
{"title":"Human TRPV1 is an efficient thermogenetic actuator for chronic neuromodulation.","authors":"Dmitry I Maltsev, Maxim A Solotenkov, Liana F Mukhametshina, Rostislav A Sokolov, Georgy M Solius, David Jappy, Aleksandra S Tsopina, Ilya V Fedotov, Aleksandr A Lanin, Andrei B Fedotov, Viktoriya G Krut', Yulia G Ermakova, Aleksandr A Moshchenko, Andrei Rozov, Aleksei M Zheltikov, Oleg V Podgorny, Vsevolod V Belousov","doi":"10.1007/s00018-024-05475-x","DOIUrl":"https://doi.org/10.1007/s00018-024-05475-x","url":null,"abstract":"<p><p>Thermogenetics is a promising neuromodulation technique based on the use of heat-sensitive ion channels. However, on the way to its clinical application, a number of questions have to be addressed. First, to avoid immune response in future human applications, human ion channels should be studied as thermogenetic actuators. Second, heating levels necessary to activate these channels in vivo in brain tissue should be studied and cytotoxicity of these temperatures addressed. Third, the possibility and safety of chronic neuromodulation has to be demonstrated. In this study, we present a comprehensive framework for thermogenetic neuromodulation in vivo using the thermosensitive human ion channel hTRPV1. By targeting hTRPV1 expression to excitatory neurons of the mouse brain and activating them within a non-harmful temperature range with a fiber-coupled infrared laser, we not only induced neuronal firing and stimulated locomotion in mice, but also demonstrated that thermogenetics can be employed for repeated neuromodulation without causing evident brain tissue injury. Our results lay the foundation for the use of thermogenetic neuromodulation in brain research and therapy of neuropathologies.</p>","PeriodicalId":10007,"journal":{"name":"Cellular and Molecular Life Sciences","volume":"81 1","pages":"437"},"PeriodicalIF":6.2,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11502623/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142496093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marika Foglia, Luca Guarrera, Mami Kurosaki, Giada Andrea Cassanmagnago, Marco Bolis, Matteo Miduri, Anna Cereseto, Alessandro Umbach, Ilaria Craparotta, Maddalena Fratelli, Arianna Vallerga, Gabriela Paroni, Adriana Zanetti, Andrea Vincenzo Cavallaro, Luca Russo, Enrico Garattini, Mineko Terao
{"title":"The NIPBL-gene mutation of a Cornelia de Lange Syndrome patient causes deficits in the hepatocyte differentiation of induced Pluripotent Stem Cells via altered chromatin-accessibility.","authors":"Marika Foglia, Luca Guarrera, Mami Kurosaki, Giada Andrea Cassanmagnago, Marco Bolis, Matteo Miduri, Anna Cereseto, Alessandro Umbach, Ilaria Craparotta, Maddalena Fratelli, Arianna Vallerga, Gabriela Paroni, Adriana Zanetti, Andrea Vincenzo Cavallaro, Luca Russo, Enrico Garattini, Mineko Terao","doi":"10.1007/s00018-024-05481-z","DOIUrl":"10.1007/s00018-024-05481-z","url":null,"abstract":"<p><p>The Cornelia de Lange syndrome (CdLS) is a rare genetic disease, which is characterized by a cohesinopathy. Mutations of the NIPBL gene are observed in 65% of CdLS patients. A novel iPSC (induced Pluripotent Stem Cell) line was reprogrammed from the leukocytes of a CdLS patient carrying a missense mutation of the NIPBL gene. A mutation-corrected isogenic iPSC-line and two iPSC-lines generated from the healthy parents were used as controls. The iPSC lines were differentiated along the hepatocyte-lineage. Comparative immunofluorescence, RNA-seq and ATAC-seq analyses were performed on undifferentiated and differentiated iPSCs. In addition, chromatin organization was studied by ChIP-Seq analysis on the patient derived iPSCs as well as the respective controls. Relative to the mutation-corrected and the healthy-parents iPSCs, the patient-derived counterparts are defective in terms of differentiation along the hepatocyte-lineage. One-third of the genes selectively up-regulated in CdLS-derived iPSCs and hepatic cells are non-protein-coding genes. By converse, most of the selectively down-regulated genes code for transcription factors and proteins regulating neural differentiation. Some of the transcriptionally silenced loci, such as the DPP6 gene on chromosome 7q36.2 and the ZNF gene cluster on chromosome 19p12, are located in closed-chromatin regions. Relative to the corresponding controls, the global transcriptomic differences observed in CdLS undifferentiated iPSCs are associated with altered chromatin accessibility, which was confirmed by ChIP-Seq analysis. Thus, the deficits in the differentiation along the hepatocyte lineage observed in our CdLS patient is likely to be due to a transcriptional dysregulation resulting from a cohesin-dependent alteration of chromatin accessibility.</p>","PeriodicalId":10007,"journal":{"name":"Cellular and Molecular Life Sciences","volume":"81 1","pages":"439"},"PeriodicalIF":6.2,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11511806/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142496096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Weixia Xuan, Xu Wu, Longcheng Zheng, Huayun Jia, Xiaoju Zhang, Xulong Zhang, Bin Cao
{"title":"Gut microbiota-derived acetic acids promoted sepsis-induced acute respiratory distress syndrome by delaying neutrophil apoptosis through FABP4.","authors":"Weixia Xuan, Xu Wu, Longcheng Zheng, Huayun Jia, Xiaoju Zhang, Xulong Zhang, Bin Cao","doi":"10.1007/s00018-024-05474-y","DOIUrl":"https://doi.org/10.1007/s00018-024-05474-y","url":null,"abstract":"<p><p>In patients with sepsis, neutrophil apoptosis tends to be inversely proportional to the severity of sepsis, but its mechanism is not yet clear. This study aimed to explore the mechanism of fatty acid binding protein 4 (FABP4) regulating neutrophil apoptosis through combined analysis of gut microbiota and short-chain fatty acids (SCFAs) metabolism. First, neutrophils from bronchoalveolar lavage fluid (BALF) of patients with sepsis-induced acute respiratory distress syndrome (ARDS) were purified and isolated RNA was applied for sequencing. Then, the cecal ligation and puncture (CLP) method was applied to induce the mouse sepsis model. After intervention with differential SCFAs sodium acetate, neutrophil apoptosis and FABP4 expression were further analyzed. Then, FABP4 inhibitor BMS309403 was used to treat neutrophils. We found CLP group had increased lung injury score, lung tissue wet/dry ratio, lung vascular permeability, and inflammatory factors IL-1β, TNF-α, IL-6, IFN-γ, and CCL3 levels in both bronchoalveolar lavage fluid and lung tissue. Additionally, FABP4 was lower in neutrophils of ARDS patients and mice. Meanwhile, CLP-induced dysbiosis of gut microbiota and changes in SCFAs levels were observed. Further verification showed that acetic acids reduced neutrophil apoptosis and FABP4 expression via FFAR2. Besides, FABP4 affected neutrophil apoptosis through endoplasmic reticulum (ER) stress, and neutrophil depletion alleviated the promotion of ARDS development by BMS309403. Moreover, FABP4 in neutrophils regulated the injury of RLE-6TN through inflammatory factors. In conclusion, FABP4 affected by gut microbiota-derived SCFAs delayed neutrophil apoptosis through ER stress, leading to increased inflammatory factors mediating lung epithelial cell damage.</p>","PeriodicalId":10007,"journal":{"name":"Cellular and Molecular Life Sciences","volume":"81 1","pages":"438"},"PeriodicalIF":6.2,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11511807/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142496092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"N6-methyladenosine-modified circCDK14 promotes ossification of the ligamentum flavum via epigenetic modulation by targeting AFF4.","authors":"Yongzhao Zhao, Longting Chen, Qian Xiang, Jialiang Lin, Shuai Jiang, Weishi Li","doi":"10.1007/s00018-024-05460-4","DOIUrl":"10.1007/s00018-024-05460-4","url":null,"abstract":"<p><strong>Background: </strong>The ligamentum flavum (LF) is an important anatomical structure of the spine. Ossification of the LF (OLF) has become the leading cause of thoracic spinal stenosis. Circular RNAs (circRNAs) and N6-methyladenosine (m6A) modification are reported to be associated with several human diseases. However, the role of circRNAs and m6A modification in the pathogenesis of OLF has not been fully investigated. Here, we aimed to explore the vital function of circRNAs and m6A modification in OLF.</p><p><strong>Materials and methods: </strong>We analysed the circRNA expression of 4 OLF tissues and 4 normal LF tissues using bioinformatic analysis and identified circCDK14 for further analysis. We investigated the effects of circCDK14 on the osteogenic differentiation of LF cells. We observed that circCDK14 regulated its target genes by binding to miRNAs as a miRNA sponge. Moreover, the circRNA pull-down assay indicated that RNA-binding proteins might regulate the expression of circCDK14 via m6A modification.</p><p><strong>Results: </strong>CircCDK14 was significantly upregulated in OLF tissues compared to normal LF tissues. Overexpression of circCDK14 promoted the osteogenic differentiation of LF cells. Mechanistically, CircCDK14 promoted the expression of ALF transcription elongation Factor 4 (AFF4) by serving as a sponge for miR-93-5p. Moreover, Wilms tumour 1-associated protein (WTAP) increased the stability of circCDK14 via N6-methyladenosine modification.</p><p><strong>Conclusion: </strong>The m6A-modified CircCDK14 binding to miR-93-5p played an important role in the osteogenesis of LF cells by targeting AFF4, providing a promising therapeutic target for OLF.</p>","PeriodicalId":10007,"journal":{"name":"Cellular and Molecular Life Sciences","volume":"81 1","pages":"436"},"PeriodicalIF":6.2,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11488824/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142459322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Oliver Goldmann, Julia C Lang, Manfred Rohde, Tobias May, Gabriella Molinari, Eva Medina
{"title":"Alpha-hemolysin promotes internalization of Staphylococcus aureus into human lung epithelial cells via caveolin-1- and cholesterol-rich lipid rafts.","authors":"Oliver Goldmann, Julia C Lang, Manfred Rohde, Tobias May, Gabriella Molinari, Eva Medina","doi":"10.1007/s00018-024-05472-0","DOIUrl":"10.1007/s00018-024-05472-0","url":null,"abstract":"<p><p>Staphylococcus aureus is a pathogen associated with severe respiratory infections. The ability of S. aureus to internalize into lung epithelial cells complicates the treatment of respiratory infections caused by this bacterium. In the intracellular environment, S. aureus can avoid elimination by the immune system and the action of circulating antibiotics. Consequently, interfering with S. aureus internalization may represent a promising adjunctive therapeutic strategy to enhance the efficacy of conventional treatments. Here, we investigated the host-pathogen molecular interactions involved in S. aureus internalization into human lung epithelial cells. Lipid raft-mediated endocytosis was identified as the main entry mechanism. Thus, bacterial internalization was significantly reduced after the disruption of lipid rafts with methyl-β-cyclodextrin. Confocal microscopy confirmed the colocalization of S. aureus with lipid raft markers such as ganglioside GM1 and caveolin-1. Adhesion of S. aureus to α5β1 integrin on lung epithelial cells via fibronectin-binding proteins (FnBPs) was a prerequisite for bacterial internalization. A mutant S. aureus strain deficient in the expression of alpha-hemolysin (Hla) was significantly impaired in its capacity to enter lung epithelial cells despite retaining its capacity to adhere. This suggests a direct involvement of Hla in the bacterial internalization process. Among the receptors for Hla located in lipid rafts, caveolin-1 was essential for S. aureus internalization, whereas ADAM10 was dispensable for this process. In conclusion, this study supports a significant role of lipid rafts in S. aureus internalization into human lung epithelial cells and highlights the interaction between bacterial Hla and host caveolin-1 as crucial for the internalization process.</p>","PeriodicalId":10007,"journal":{"name":"Cellular and Molecular Life Sciences","volume":"81 1","pages":"435"},"PeriodicalIF":6.2,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11488825/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142459318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Seth M Moore, Joseph Gawron, Mckayla Stevens, Leandro N Marziali, Emmanuel S Buys, G Todd Milne, Maria Laura Feltri, Jordan J S VerPlank
{"title":"Pharmacologically increasing cGMP improves proteostasis and reduces neuropathy in mouse models of CMT1.","authors":"Seth M Moore, Joseph Gawron, Mckayla Stevens, Leandro N Marziali, Emmanuel S Buys, G Todd Milne, Maria Laura Feltri, Jordan J S VerPlank","doi":"10.1007/s00018-024-05463-1","DOIUrl":"https://doi.org/10.1007/s00018-024-05463-1","url":null,"abstract":"<p><p>Increasing cyclic GMP activates 26S proteasomes via phosphorylation by Protein Kinase G and stimulates the intracellular degradation of misfolded proteins. Therefore, agents that raise cGMP may be useful therapeutics against neurodegenerative diseases and other diseases in which protein degradation is reduced and misfolded proteins accumulate, including Charcot Marie Tooth 1A and 1B peripheral neuropathies, for which there are no treatments. Here we increased cGMP in the S63del mouse model of CMT1B by treating for three weeks with either the phosphodiesterase 5 inhibitor tadalafil, or the brain-penetrant soluble guanylyl cyclase stimulator CYR119. Both molecules activated proteasomes in the affected peripheral nerves, reduced polyubiquitinated proteins, and improved myelin thickness and nerve conduction. CYR119 increased cGMP more than tadalafil in the peripheral nerves of S63del mice and elicited greater biochemical and functional improvements. To determine whether raising cGMP could be beneficial in other neuropathies, we first showed that polyubiquitinated proteins and the disease-causing protein accumulate in the sciatic nerves of the C3 mouse model of CMT1A. Treatment of these mice with CYR119 reduced the levels of polyubiquitinated proteins and the disease-causing protein, presumably by increasing their degradation, and improved myelination, nerve conduction, and motor coordination. Thus, pharmacological agents that increase cGMP are promising treatments for CMT1 neuropathies and may be useful against other proteotoxic and neurodegenerative diseases.</p>","PeriodicalId":10007,"journal":{"name":"Cellular and Molecular Life Sciences","volume":"81 1","pages":"434"},"PeriodicalIF":6.2,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11473742/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142459323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tianyu Wu, Yao Lu, Yue Yu, Yan Hua, Gaoyuan Ge, Wei Zhao, Kaiyan Chen, Zhuen Zhong, Fengxiang Zhang
{"title":"Long noncoding RNA AK144717 exacerbates pathological cardiac hypertrophy through modulating the cellular distribution of HMGB1 and subsequent DNA damage response.","authors":"Tianyu Wu, Yao Lu, Yue Yu, Yan Hua, Gaoyuan Ge, Wei Zhao, Kaiyan Chen, Zhuen Zhong, Fengxiang Zhang","doi":"10.1007/s00018-024-05464-0","DOIUrl":"10.1007/s00018-024-05464-0","url":null,"abstract":"<p><p>DNA damage induced by oxidative stress during cardiac hypertrophy activates the ataxia telangiectasia mutated (ATM)-mediated DNA damage response (DDR) signaling, in turn aggravating the pathological cardiomyocyte growth. This study aims to identify the functional associations of long noncoding RNA (lncRNAs) with cardiac hypertrophy and DDR. The altered ventricular lncRNAs in the mice between sham and transverse aortic constriction (TAC) group were identified by microarray analysis, and a novel lncRNA AK144717 was found to gradually upregulate during the development of pathological cardiac hypertrophy induced by TAC surgery or angiotensin II (Ang II) stimulation. Silencing AK144717 had a similar anti-hypertrophic effect to that of ATM inhibitor KU55933 and also suppressed the activated ATM-DDR signaling induced by hypertrophic stimuli. The involvement of AK144717 in DDR and cardiac hypertrophy was closely related to its interaction with HMGB1, as silencing HMGB1 abolished the effects of AK144717 knockdown. The binding of AK144717 to HMGB1 prevented the interaction between HMGB1 and SIRT1, contributing to the increased acetylation and then cytosolic translocation of HMGB1. Overall, our study highlights the role of AK144717 in the hypertrophic response by interacting with HMGB1 and regulating DDR, hinting that AK144717 is a promising therapeutic target for pathological cardiac growth.</p>","PeriodicalId":10007,"journal":{"name":"Cellular and Molecular Life Sciences","volume":"81 1","pages":"432"},"PeriodicalIF":6.2,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11470913/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142459319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"MERS-CoV-nsp5 expression in human epithelial BEAS 2b cells attenuates type I interferon production by inhibiting IRF3 nuclear translocation.","authors":"Y Zhang, S Kandwal, D Fayne, N J Stevenson","doi":"10.1007/s00018-024-05458-y","DOIUrl":"10.1007/s00018-024-05458-y","url":null,"abstract":"<p><p>Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is an enveloped, positive-sense RNA virus that emerged in 2012, causing sporadic cases and localized outbreaks of severe respiratory illness with high fatality rates. A characteristic feature of the immune response to MERS-CoV infection is low type I IFN induction, despite its importance in viral clearance. The non-structural proteins (nsps) of other coronaviruses have been shown to block IFN production. However, the role of nsp5 from MERS-CoV in IFN induction of human respiratory cells is unclear. In this study, we elucidated the role of MERS-CoV-nsp5, the viral main protease, in modulating the host's antiviral responses in human bronchial epithelial BEAS 2b cells. We found that overexpression of MERS-CoV-nsp5 had a dose-dependent inhibitory effect on IFN-β promoter activation and cytokine production induced by HMW-poly(I:C). It also suppressed IFN-β promoter activation triggered by overexpression of key components in the RIG-I-like receptor (RLR) pathway, including RIG-I, MAVS, IKK-ε and IRF3. Moreover, the overexpression of MERS-CoV-nsp5 did not impair expression or phosphorylation of IRF3, but suppressed the nuclear translocation of IRF3. Further investigation revealed that MERS-CoV-nsp5 specifically interacted with IRF3. Using docking and molecular dynamic (MD) simulations, we also found that amino acids on MERS-CoV-nsp5, IRF3, and KPNA4 may participate in protein-protein interactions. Additionally, we uncovered protein conformations that mask the nuclear localization signal (NLS) regions of IRF3 and KPNA4 when interacting with MERS-CoV-nsp5, suggesting a mechanism by which this viral protein blocks IRF3 nuclear translocation. Of note, the IFN-β expression was restored after administration of protease inhibitors targeting nsp5, indicating this suppression of IFN-β production was dependent on the enzyme activity of nsp5. Collectively, our findings elucidate a mechanism by which MERS-CoV-nsp5 disrupts the host's innate antiviral immunity and thus provides insights into viral pathogenesis.</p>","PeriodicalId":10007,"journal":{"name":"Cellular and Molecular Life Sciences","volume":"81 1","pages":"433"},"PeriodicalIF":6.2,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11470912/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142459320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stephan Tetenborg, Fatemeh Ariakia, Elizabeth Martinez-Soler, Eyad Shihabeddin, Ignacio Cebrian Lazart, Adam C Miller, John O'Brien
{"title":"Regulation of Cx36 trafficking through the early secretory pathway by COPII cargo receptors and Grasp55.","authors":"Stephan Tetenborg, Fatemeh Ariakia, Elizabeth Martinez-Soler, Eyad Shihabeddin, Ignacio Cebrian Lazart, Adam C Miller, John O'Brien","doi":"10.1007/s00018-024-05440-8","DOIUrl":"10.1007/s00018-024-05440-8","url":null,"abstract":"<p><p>Gap junctions formed by the major neuronal connexin Cx36 function as electrical synapses in the nervous system and provide unique functions such as synchronizing neuron activities or supporting network oscillations. Although the physiological significance of electrical synapses for neuronal networks is well established, little is known about the pathways that regulate the transport of its main component: Cx36. Here we have used HEK293T cells as an expression system in combination with siRNA and BioID screens to study the transition of Cx36 from the ER to the cis Golgi. Our data indicate that the C-terminal tip of Cx36 is a key factor in this process, mediating binding interactions with two distinct components in the early secretory pathway: the COPII complex and the Golgi stacking protein Grasp55. The C-terminal amino acid valine serves as an ER export signal to recruit COPII cargo receptors Sec24A/B/C at ER exit sites, whereas the PDZ binding motif \"SAYV\" mediates an interaction with Grasp55. These two interactions have opposing effects in their respective compartments. While Sec24 subunits carry Cx36 out of the ER, Grasp55 stabilizes Cx36 in the Golgi as shown in over expression experiments. These early regulatory steps of Cx36 are expected to be essential for the formation, function, regulation and plasticity of electrical synapses in the developing and mature nervous system.</p>","PeriodicalId":10007,"journal":{"name":"Cellular and Molecular Life Sciences","volume":"81 1","pages":"431"},"PeriodicalIF":6.2,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11470877/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142459324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}