AutophagyPub Date : 2025-06-01Epub Date: 2025-01-11DOI: 10.1080/15548627.2024.2448913
Caiwei Song, Qincai Dong, Yi Yao, Yan Cui, Chunmei Zhang, Lijun Lin, Lin Zhu, Yong Hu, Hainan Liu, Yanwen Jin, Ping Li, Xuan Liu, Cheng Cao
{"title":"Nonreceptor tyrosine kinase ABL1 regulates lysosomal acidification by phosphorylating the ATP6V1B2 subunit of the vacuolar-type H<sup>+</sup>-ATPase.","authors":"Caiwei Song, Qincai Dong, Yi Yao, Yan Cui, Chunmei Zhang, Lijun Lin, Lin Zhu, Yong Hu, Hainan Liu, Yanwen Jin, Ping Li, Xuan Liu, Cheng Cao","doi":"10.1080/15548627.2024.2448913","DOIUrl":"10.1080/15548627.2024.2448913","url":null,"abstract":"<p><p>The vacuolar-type H<sup>+</sup>-ATPase (V-ATPase) is a proton pump responsible for controlling the intracellular and extracellular pH of cells. Its activity and assembly are tightly controlled by multiple pathways, of which phosphorylation-mediated regulation is poorly understood. In this report, we show that in response to starvation stimuli, the nonreceptor tyrosine kinase ABL1 directly interacts with ATP6V1B2, a subunit of the V<sub>1</sub> domain of the V-ATPase, and phosphorylates ATP6V1B2 at Y68. Y68 phosphorylation in ATP6V1B2 facilitates the recruitment of the ATP6V1D subunit into the V<sub>1</sub> subcomplex of V-ATPase, therefore potentiating the assembly of the V<sub>1</sub> subcomplex with the membrane-embedded V<sub>0</sub> subcomplex to form the integrated functional V-ATPase. ABL1 inhibition or depletion impairs V-ATPase assembly and lysosomal acidification, resulting in an increased lysosomal pH, a decreased lysosomal hydrolase activity, and consequently, the suppressed degradation of lumenal cargo during macroautophagy/autophagy. Consistently, the efficient removal of damaged mitochondrial residues during mitophagy is also impeded by ABL1 deficiency. Our findings suggest that ABL1 is a crucial autophagy regulator that maintains the adequate lysosomal acidification required for both physiological conditions and stress responses.<b>Abbreviation</b>: ANOVA: analysis of variance; Baf A1: bafilomycin A1; CCCP: carbonyl cyanide 3-chlorophenylhydrazone; CRK: CRK proto-oncogene, adaptor protein; CTSD: cathepsin D; DMSO: dimethylsulfoxide; EBSS: Earle's balanced salt solution; FITC: fluorescein isothiocyanate; GFP: green fluorescent protein; GST: glutathione S-transferase; LAMP2: lysosomal associated membrane protein 2; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTORC1: mechanistic target of rapamycin kinase complex 1; PD: Parkinson disease; PLA: proximity ligation assay; RFP: red fluorescent protein; WT: wild-type.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1192-1211"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142932467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AutophagyPub Date : 2025-06-01Epub Date: 2025-02-19DOI: 10.1080/15548627.2025.2465396
Meng-Meng Wang, Wuyang Wang, Jiansong Qi
{"title":"Lysosomal Fe<sup>2+</sup> influx through MCOLN1 channel prevents sustained inflammation by limiting PHDs-regulated NFKB activation in macrophages.","authors":"Meng-Meng Wang, Wuyang Wang, Jiansong Qi","doi":"10.1080/15548627.2025.2465396","DOIUrl":"10.1080/15548627.2025.2465396","url":null,"abstract":"<p><p>Lysosomes are best known for their involvement in inflammatory responses, where they participate in the macroautophagy/autophagy process to eliminate inflammasomes. Recently, we have identified a previously overlooked function of lysosomes in regulating macrophage inflammatory responses. Specifically, lysosomes finely control the production of IL1B (interleukin 1 beta) by manipulating the release of lysosomal Fe<sup>2+</sup> through MCOLN1. Mechanistically, reactive oxygen species (ROS), accumulated during sustained inflammation in macrophages, cause activation of the MCOLN1, a lysosomal cationic channel. The activation of MCOLN1 triggers the release of lysosomal Fe<sup>2</sup> toward the cytosol, which in turn activates prolyl hydroxylase domain enzymes (PHDs). PHDs' activation represses the transcriptional regulator NFKB/NF-kB (nuclear factor kappa B) activity by restraining RELA/p65 in the cytosol, leading to decreased <i>IL1B</i> transcription in macrophages. Consequently, the property of controlling production and subsequent release of IL1B from macrophages allows the lysosome to finely restrict sustained inflammatory responses. These findings demonstrate that apart from relying on its degradative capability, the lysosome also limits excessive inflammatory responses to facilitate the restoration of cellular and tissue homeostasis in macrophages by modulating the release of lysosomal Fe<sup>2+</sup> through MCOLN1. Even more, by suppressing IL1B production, <i>in vivo</i> stimulation of the MCOLN1 channel alleviates multiple clinical symptoms of dextran sulfate sodium (DSS)-induced colitis in mice, highlighting MCOLN1 as a promising therapeutic target for inflammatory bowel disease (IBD) in clinical settings.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1376-1378"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143401024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AutophagyPub Date : 2025-06-01Epub Date: 2024-07-11DOI: 10.1080/15548627.2024.2377421
Yuxiang Huang, Daniel J Klionsky
{"title":"Pho81 is a novel regulator of pexophagy induced by phosphate starvation.","authors":"Yuxiang Huang, Daniel J Klionsky","doi":"10.1080/15548627.2024.2377421","DOIUrl":"10.1080/15548627.2024.2377421","url":null,"abstract":"<p><p>In the budding yeast <i>Saccharomyces cerevisiae</i>, macroautophagy/autophagy can be induced by various types of starvation. It is thought that potential autophagic substrates vary to meet specific nutritional demands under different starvation conditions. In a recent study, Gross <i>et al</i>. found that autophagy induced by phosphate starvation includes many selective aspects. For example, this work identified Pho81 as a regulator of pexophagy under conditions of phosphate starvation. Pho81 senses phosphate metabolites and directly interacts with Atg11 to promote Atg1-mediated Atg11 phosphorylation. This finding provides an example of how modulation of the Atg1/ULK kinase complex can convey specific metabolic information to regulate autophagic substrates.<b>Abbreviation</b>: AKC: Atg1/ULK kinase complex.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1171-1172"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141592415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AutophagyPub Date : 2025-06-01Epub Date: 2025-01-14DOI: 10.1080/15548627.2024.2447213
Yiu Wing Sunny Cheung, Sung-Eun Nam, Gage M J Fairlie, Karlton Scheu, Jennifer M Bui, Hannah R Shariati, Jörg Gsponer, Calvin K Yip
{"title":"Structure of the human autophagy factor EPG5 and the molecular basis of its conserved mode of interaction with Atg8-family proteins.","authors":"Yiu Wing Sunny Cheung, Sung-Eun Nam, Gage M J Fairlie, Karlton Scheu, Jennifer M Bui, Hannah R Shariati, Jörg Gsponer, Calvin K Yip","doi":"10.1080/15548627.2024.2447213","DOIUrl":"10.1080/15548627.2024.2447213","url":null,"abstract":"<p><p>The multi-step macroautophagy/autophagy process ends with the cargo-laden autophagosome fusing with the lysosome to deliver the materials to be degraded. The metazoan-specific autophagy factor EPG5 plays a crucial role in this step by enforcing fusion specificity and preventing mistargeting. How EPG5 exerts its critical function and how its deficiency leads to diverse phenotypes of the rare multi-system disorder Vici syndrome are not fully understood. Here, we report the first structure of human EPG5 (HsEPG5) determined by cryo-EM and AlphaFold2 modeling. Our structure revealed that HsEPG5 is constructed from helical bundles analogous to tethering factors in membrane trafficking pathways but contains a unique protruding thumb domain positioned adjacent to the atypical tandem LIR motifs involved in interaction with the GABARAP subfamily of Atg8-family proteins. Our NMR spectroscopic, molecular dynamics simulations and AlphaFold modeling studies showed that the HsEPG5 tandem LIR motifs only bind the canonical LIR docking site (LDS) on GABARAP without engaging in multivalent interaction. Our co-immunoprecipitation analysis further indicated that full-length HsEPG5-GABARAP interaction is mediated primarily by LIR1. Finally, our biochemical affinity isolation, X-ray crystallographic analysis, affinity measurement, and AlphaFold modeling demonstrated that this mode of binding is observed between <i>Caenorhabditis elegans</i> EPG-5 and its Atg8-family proteins LGG-1 and LGG-2. Collectively our work generated novel insights into the structural properties of EPG5 and how it potentially engages with the autophagosome to confer fusion specificity.<b>ABBREVIATIONS</b>: ATG: autophagy related; CSP: chemical shift perturbation; eGFP: enhanced green fluoresent protein; EM: electron microscopy; EPG5: ectopic P-granules 5 autophagy tethering factor; GST: glutathione S-transferase; HP: hydrophobic pocket; HSQC: heteronuclear single-quantum correlation; ITC: isothermal titration calorimetry; LDS: LC3 docking site; LIR: LC3-interacting region; MD: molecular dynamics; NMR: nuclear magnetic resonance; TEV: tobacco etch virus.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1173-1191"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142985867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AutophagyPub Date : 2025-06-01Epub Date: 2025-02-24DOI: 10.1080/15548627.2025.2465404
Jaebeom Kim, Young Suk Yu, Keun Il Kim, Sung Hee Baek
{"title":"Transcriptional repression of autophagy and lysosome biogenesis.","authors":"Jaebeom Kim, Young Suk Yu, Keun Il Kim, Sung Hee Baek","doi":"10.1080/15548627.2025.2465404","DOIUrl":"10.1080/15548627.2025.2465404","url":null,"abstract":"<p><p>The microphthalmia/transcription factor E (MiT/TFE) family activates macroautophagy/autophagy and lysosomal genes during acute nutrient deficiency. However, the mechanisms that suppress transcription of these genes under steady-state, nutrient-rich conditions to prevent unnecessary expression remain unclear. In this study, we identified a previously unrecognized mechanism of transcriptional repression for autophagy and lysosomal genes. Under nutrient-rich conditions, USF2 (upstream transcription factor 2) binds to the coordinated lysosomal expression and regulation (CLEAR) motif, recruiting a repressive complex containing HDAC (histone deacetylase). In contrast, during nutrient deficiency, TFEB (transcription factor EB) displaces USF2 at the same motif, activating transcription. This switch is regulated by USF2 phosphorylation at serine 155 by GSK3B (glycogen synthase kinase 3 beta). Reduced phosphorylation under nutrient-deprived conditions weakens USF2's DNA binding affinity, allowing TFEB to competitively bind and activate target genes. Knockdown or knockout of <i>Usf2</i> upregulates specific autophagy and lysosomal genes, leading to enhanced lysosomal functionality and increased autophagic flux. In USF2-deficient cells, the SERPINA1 Z variant/antitrypsin Z - an aggregation-prone mutant protein used as a model - is rapidly cleared via the autophagy-lysosome pathway. Therefore, modulation of USF2 activity may be a therapeutic strategy for managing diseases associated with autophagy and lysosomal dysfunction.<b>Abbreviation</b>: CLEAR: coordinated lysosomal expression and regulation; GSK3B: glycogen synthase kinase 3 beta; HDAC: histone deacetylase; MiT/TFE: microphthalmia/transcription factor E; NuRD: nucleosome remodeling and deacetylation; SERPINA1 Z variant/ATZ/antitrypsin Z; TFE3: transcription factor E3; TFEB: transcription factor EB; USF2: upstream transcription factor 2.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1379-1381"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143401096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AutophagyPub Date : 2025-06-01Epub Date: 2025-03-16DOI: 10.1080/15548627.2025.2466145
Meng Chen, Guowen Liu, Zhiyuan Fang, Wenwen Gao, Yuxiang Song, Lin Lei, Xiliang Du, Xinwei Li
{"title":"Buddleoside alleviates nonalcoholic steatohepatitis by targeting the AMPK-TFEB signaling pathway.","authors":"Meng Chen, Guowen Liu, Zhiyuan Fang, Wenwen Gao, Yuxiang Song, Lin Lei, Xiliang Du, Xinwei Li","doi":"10.1080/15548627.2025.2466145","DOIUrl":"10.1080/15548627.2025.2466145","url":null,"abstract":"<p><p>Nonalcoholic steatohepatitis (NASH) is a combination of hepatic steatosis, inflammation, and fibrosis, and it often follows simple hepatic steatosis in nonalcoholic fatty liver disease (NAFLD). However, no pharmacological treatment is currently available for NASH. Given the important role of TFEB (transcription factor EB) in regulating the macroautophagy/autophagy-lysosomal pathway, TFEB is potentially a novel therapeutic target for treatment of NASH, which function can be regulated by AMP-activated protein kinase (AMPK) and MTOR (mechanistic target of rapamycin kinase) complex 1 (MTORC1). Buddleoside (Bud), a natural flavonoid compound, has recently emerged as a promising drug candidate for liver diseases. Here, we shown that Bud treatment alleviated hepatic steatosis, insulin resistance, inflammation, and fibrosis in mice fed a high-fat and high-cholesterol (HFHC) diet. Notably, Bud activated AMPK, inhibited MTORC1, and enhanced TFEB transcriptional activity as well as autophagic flux <i>in vivo</i> and <i>in vitro</i>. Inhibition of AMPK or knockout of hepatic <i>Tfeb</i> abrogated the alleviation effects of Bud on hepatic steatosis, insulin resistance, inflammation, and fibrosis. Mechanistic investigation revealed that Bud bound to the PRKAB1 subunit via Val81, Arg83, and Ser108 residues and activated AMPK, thereby eliciting phosphorylation of RPTOR (regulatory associated protein of MTOR complex 1) and inhibiting the kinase MTORC1, which activated the TFEB-mediated autophagy-lysosomal pathway and further ameliorated HFHC-induced NASH in mice. Altogether, our results indicate that Bud ameliorates NASH by activating hepatic the AMPK-TFEB axis, suggesting that Bud is a potential therapeutic strategy for NASH.<b>Abbreviations:</b> ACAC, acetyl-CoA carboxylase; ADaM, allosteric drug and metabolite; AICAR, 5-aminoimidazole-4-carboxamide1-β-D-ribofuranoside; AKT, AKT serine/threonine kinase; ALP, autophagy-lysosomal pathway; AMPK, AMP-activated protein kinase; Bud, buddleoside; CAMKK2, calcium/calmodulin dependent protein kinase kinase 2; CC, compound C; CETSA, cellular thermal shift assay; C<sub>max</sub>, maximum concentration; CQ, chloroquine; DARTS, drug affinity responsive target stability assay; EIF4EBP1, eukaryotic translation factor 4E binding protein 1; GOT1, glutamic-oxaloacetic transaminase 1; GPT, glutamic-pyruvic transaminase; GSK3B, glycogen synthase kinase 3 beta; GTT, glucose-tolerance test; HFD, high fat diet; HFHC, high-fat and high-cholesterol; HOMA-IR, homeostasis model assessment of insulin resistance; IKBKB, inhibitor of nuclear factor kappa B kinase subunit beta; INSR, insulin receptor; ITT, insulin-tolerance test; LDH, lactate dehydrogenase; STK11, serine/threonine kinase 11; MAP1LC3/LC3, microtubule associated protein 1 light chain 3; MTORC1, MTOR complex 1; NAFLD, non-alcoholic fatty liver disease; NASH, non-alcoholic steatohepatitis; ND, normal diet; NFKB, nuclear factor kappa B; PA, palmitic acid; PSR, picrosirius r","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1316-1334"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143401069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AutophagyPub Date : 2025-06-01Epub Date: 2025-02-19DOI: 10.1080/15548627.2025.2465395
Lei Feng, Xibao Li, Wenjin Shen, Caiji Gao
{"title":"Stress granules as transient reservoirs for autophagy proteins: a key mechanism for plant recovery from heat stress.","authors":"Lei Feng, Xibao Li, Wenjin Shen, Caiji Gao","doi":"10.1080/15548627.2025.2465395","DOIUrl":"10.1080/15548627.2025.2465395","url":null,"abstract":"<p><p>Stress granules (SGs) are transient, non-membrane-bound cytoplasmic condensates that form in response to environmental stresses, serving as protective reservoirs for mRNAs and proteins. In plants, SGs play a crucial role in stress adaptation, but their relationship with macroautophagy/autophagy, a key process for degrading damaged organelles and misfolded proteins, remains poorly understood. In a recent study, we revealed that key autophagy proteins, including components of the ATG1-ATG13 kinase complex, the class III phosphatidylinositol 3-kinase (PtdIns3K) complex, and the ATG8-PE system, translocate to SGs during heat stress (HS) in <i>Arabidopsis thaliana</i>. Using biochemical, cell biological and genetic approaches, we demonstrated that ATG proteins accumulate on HS-induced SGs and are released to the cytosol upon SG disassembly during the post-HS recovery stage. This process facilitates rapid autophagy activation. Notably, a SG-deficient mutant (<i>ubp1abc</i>) exhibits delayed autophagy activation and impaired clearance of ubiquitinated protein aggregates, highlighting the importance of SGs in regulating autophagy. Our findings uncover a novel mechanism by which SGs sequester autophagy proteins during stress, ensuring their rapid availability for stress recovery, and provide new insights into the interplay between SGs and autophagy in plant stress responses.<b>Abbreviation</b>: ATG, autophagy related; HS, heat stress; PtdIns3K, phosphatidylinositol 3-kinase; RBP47B, RNA-binding protein 47B; SG, stress granule; UBP1, ubiquitin-specific protease 1.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1373-1375"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143461071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AutophagyPub Date : 2025-06-01Epub Date: 2025-03-10DOI: 10.1080/15548627.2025.2469129
Chenyu Luo, Haisheng Liang, Mintao Ji, Caiyong Ye, Yiping Lin, Yuhan Guo, Zhisen Zhang, Yinyin Shu, Xiaoni Jin, Shuangshuang Lu, Wanling Lu, Yazheng Dang, Hong Zhang, Bingyan Li, Guangming Zhou, Zengli Zhang, Lei Chang
{"title":"Autophagy induced by mechanical stress sensitizes cells to ferroptosis by NCOA4-FTH1 axis.","authors":"Chenyu Luo, Haisheng Liang, Mintao Ji, Caiyong Ye, Yiping Lin, Yuhan Guo, Zhisen Zhang, Yinyin Shu, Xiaoni Jin, Shuangshuang Lu, Wanling Lu, Yazheng Dang, Hong Zhang, Bingyan Li, Guangming Zhou, Zengli Zhang, Lei Chang","doi":"10.1080/15548627.2025.2469129","DOIUrl":"10.1080/15548627.2025.2469129","url":null,"abstract":"<p><p>Ferroptosis is an iron-dependent regulated form of cell death implicated in various diseases, including cancers, with its progression influenced by iron-dependent peroxidation of phospholipids and dysregulation of the redox system. Whereas the extracellular matrix of tumors provides mechanical cues influencing tumor initiation and progression, its impact on ferroptosis and its mechanisms remains largely unexplored. In this study, we reveal that heightened mechanical tension sensitizes cells to ferroptosis, whereas decreased mechanics confers resistance. Mechanistically, reduced mechanical tension reduces intracellular free iron levels by enhancing FTH1 protein expression. Additionally, low mechanics significantly diminishes NCOA4, pivotal in mediating FTH1 phase separation-induced ferritinophagy. Targeting NCOA4 effectively rescues ferroptosis susceptibility under low mechanical tension through modulation of FTH1 phase separation-driven autophagy. In conclusion, our findings demonstrate that mechanics regulates iron metabolism via NCOA4-FTH1 phase separation-mediated autophagy, thereby influencing ferroptosis sensitivity and offering promising therapeutic avenues for future exploration.<b>Abbreviations:</b> ACO1: aconitase 1; ATG5: autophagy related 5; DMSO: dimethyl sulfoxide; EGFP: enhanced green fluorescent protein; FACS: fluorescence-activated cell sorting; FER-1: ferrostatin-1; FTH1: ferritin heavy chain 1; FTL: ferritin light chain; GPX4: glutathione peroxidase 4; IR: ionizing radiation; IREB2: iron responsive element binding protein 2; NCOA4: nuclear receptor coactivator 4; NFE2L2: NFE2 like bZIP transcription factor 2; NOPP: norepinephrine; PBS: phosphate-buffered saline; PI: propidium iodide; RSL3: (1S,3 R)-RSL3; TCGA: The Cancer Genome Atlas; WWTR1: WW domain containing transcription regulator 1; YAP1: Yes1 associated transcriptional regulator.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1263-1282"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143484983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AutophagyPub Date : 2025-06-01Epub Date: 2025-02-27DOI: 10.1080/15548627.2025.2468140
Xinming Pan, Yangyang Sun, Jianan Liu, Rong Chen, Zhen Zhang, Caiying Li, Huochun Yao, Jiale Ma
{"title":"A bacterial RING ubiquitin ligase triggering stepwise degradation of BRISC via TOLLIP-mediated selective autophagy manipulates host inflammatory response.","authors":"Xinming Pan, Yangyang Sun, Jianan Liu, Rong Chen, Zhen Zhang, Caiying Li, Huochun Yao, Jiale Ma","doi":"10.1080/15548627.2025.2468140","DOIUrl":"10.1080/15548627.2025.2468140","url":null,"abstract":"<p><p>Numerous bacterial pathogens have evolved tactics to interfere with the host ubiquitination network to evade clearance by the innate immune system. Nevertheless, the subtle antagonism between a bacterial ubiquitinase and a host deubiquitinase, through which they modify their respective targets within a multifaceted network, has yet to be characterized. BRCC3 isopeptidase complex (BRISC) is a newly identified K63-specific deubiquitinase complex that plays a crucial role in cellular signaling pathways such as inflammation. NleG, a type III secretion system (T3SS) effector, contains a conserved RING E3 ubiquitin ligase domain that interacts with host ubiquitination machinery, along with a distinct substrate-recognition domain that targets host proteins. Here, one particular variant, NleG6, was identified as mediating K27- and K29-linked polyubiquitination at residues K89 and K114 of ABRAXAS2/FAM175B, a scaffolding protein within the BRISC complex, leading to its degradation through TOLLIP (toll interacting protein)-mediated selective autophagy. Further investigations elucidated that ABRAXAS2 degradation triggered the subsequent degradation of adjacent BRCC3, which in turn, hindered TNIP1/ABIN1 degradation, ultimately inhibiting NFKB/NF-κB (nuclear factor kappa B)-mediated inflammatory responses. This chain of events offers valuable insights into the NFKB activation by the K63-specific deubiquitinating role of BRISC, unveiling how bacteria manipulate ubiquitin regulation and selective autophagy within the BRISC network to inhibit the host's inflammatory response and thus dominate a pathogen-host tug-of-war.<b>Abbreviations:</b> 3-MA: 3-methyladenine; A/E: attaching and effacing; ATG7: autophagy related 7; BafA1: bafilomycin A<sub>1</sub>; BNIP3L/Nix: BCL2 interacting protein 3 like; BRISC: BRCC3 isopeptidase complex; Cas9: CRISPR-associated system 9; co-IP: co-immunoprecipitation; CQ: chloroquine; CRISPR: clustered regulatory interspaced short palindromic repeat; DAPI: 4',6-diamidino2-phenylindole; DMSO: dimethyl sulfoxide; DUB: deubiquitinating enzyme; <i>E. coli</i>: <i>Escherichia coli</i>; EHEC: enterohemorrhagic <i>Escherichia coli</i>; EPEC: enteropathogenic <i>Escherichia coli</i>; GFP: green fluorescent protein; LEE: locus of enterocyte effacement; MAP1LC3B/LC3: microtubule associated protein 1 light chain 3 beta; MG132: cbz-leu-leu-leucinal; MOI: multiplicity of infection; NBR1: NBR1 autophagy cargo receptor; NC: negative control; NFKB/NF-κB: nuclear factor kappa B; NH<sub>4</sub>Cl: ammonium chloride; OPTN: optineurin; SQSTM1/p62: sequestosome 1; sgRNAs: small guide RNAs; T3SS: type III secretion system; TNF: tumor necrosis factor; TOLLIP: toll interacting protein; TRAF: TNF receptor associated factor; TUBB: tubulin beta class I; WCL: whole cell lysate; WT: wide type.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1353-1372"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143517670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}