AutophagyPub Date : 2025-09-01Epub Date: 2025-05-25DOI: 10.1080/15548627.2025.2508935
Min Seok Song, Hun Ju Sim, Shin Hye Noh, Vivek Malhotra, Min Goo Lee
{"title":"ER tubular body: an ER-derived compartment for redirecting autophagy to secretory functions.","authors":"Min Seok Song, Hun Ju Sim, Shin Hye Noh, Vivek Malhotra, Min Goo Lee","doi":"10.1080/15548627.2025.2508935","DOIUrl":"10.1080/15548627.2025.2508935","url":null,"abstract":"<p><p>The secretion of proteins that do not follow the well-characterized endoplasmic reticulum (ER)-Golgi apparatus pathway, known as unconventional protein secretion (UCPS), is gradually revealing its complexities. Our study has identified an ER-based tubulovesicular network, termed ER tubular body (ER-TB), as a central compartment in this process. We demonstrate that ER-TBs are formed by two reticulophagy receptors, ATL3 and RTN3L, under conditions of cellular stress. In addition to their role in stress-induced secretion, the activation of UCPS via ER-TBs facilitates cell surface trafficking of trafficking-deficient transmembrane proteins such as ΔF508-CFTR. Furthermore, their involvement in ER remodeling and vesicle trafficking suggests a potential role in viral replication, particularly in the formation of membrane compartments utilized by positive-strand RNA viruses. By uncovering ER-TBs as key cellular structures in stress-induced UCPS and demonstrating their regulation by autophagy-related factors, our findings offer valuable insights into protein homeostasis, viral pathogenesis, and potential therapeutic strategies for diseases linked to trafficking defects.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"2082-2084"},"PeriodicalIF":14.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12363525/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144103306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AutophagyPub Date : 2025-09-01Epub Date: 2025-04-25DOI: 10.1080/15548627.2025.2496364
Mingzhu Tang, Guang Lu, Han-Ming Shen
{"title":"SMAD3 and PINK1 constitute a new positive feedback loop in regulation of mitophagy.","authors":"Mingzhu Tang, Guang Lu, Han-Ming Shen","doi":"10.1080/15548627.2025.2496364","DOIUrl":"10.1080/15548627.2025.2496364","url":null,"abstract":"<p><p>Mitophagy, selective degradation of dysfunctional mitochondria by the autophagy-lysosome pathway, is critical for maintaining cellular homeostasis. In recent years, significant progress has been made in understanding how PINK1 (PTEN-induced kinase 1)-mediated phosphorylation and the E3 ubiquitin (Ub) ligase (PRKN/parkin)-mediated ubiquitination form a positive feedforward loop in control of mitophagy. Nevertheless, a fundamental question remains: How is PINK1 transcriptionally modulated under mitochondrial stress to finely support mitophagy? Recently, we unveiled a novel mechanism in control of <i>PINK1</i> transcription by SMAD3 (SMAD family member 3), an essential component of the TGFB/TGFβ (transforming growth factor beta)-SMAD signaling pathway. Upon mitochondrial depolarization, SMAD3 is activated through PINK1-mediated phosphorylation of SMAD3 at serine 423/425 independent of canonical TGFB signaling. More importantly, the SMAD3-PINK1 regulatory axis appears to functionally provide a pro-survival mechanism against mitochondrial stress. Therefore, PINK1 and SMAD3 constitute a newly discovered positive feedforward loop to regulate mitophagy, highlighting the need for further exploring the crosstalk between TGFB-SMAD signaling and mitophagy.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"2074-2076"},"PeriodicalIF":14.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12363504/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144060321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AutophagyPub Date : 2025-09-01Epub Date: 2025-05-30DOI: 10.1080/15548627.2025.2506292
Hayder M Al-Kuraishy, Majid S Jabir, Ali I Al-Gareeb, Ali K Albuhadily, Daniel J Klionsky, Mayyadah F Rafeeq
{"title":"Epilepsy and autophagy modulators: a therapeutic split.","authors":"Hayder M Al-Kuraishy, Majid S Jabir, Ali I Al-Gareeb, Ali K Albuhadily, Daniel J Klionsky, Mayyadah F Rafeeq","doi":"10.1080/15548627.2025.2506292","DOIUrl":"10.1080/15548627.2025.2506292","url":null,"abstract":"<p><p>Epilepsy is a neurological disease characterized by repeated unprovoked seizure. Epilepsy is controlled by anti-epileptic drugs (AEDs); however, one third of epileptic patients have symptoms that are not controlled by AEDs in a condition called refractory epilepsy. Dysregulation of macroautophagy/autophagy is involved in the pathogenesis of epilepsy. Autophagy prevents the development and progression of epilepsy through regulating the balance between inhibitory and excitatory neurotransmitters. Induction of autophagy and autophagy-related proteins could be a novel therapeutic strategy in the management of epilepsy. Despite the protective role of autophagy against epileptogenesis and epilepsy, its role in status epilepticus is perplexing and might reflect its nature as a double-edged sword. Autophagy inducers play a critical role in reducing seizure frequency and severity, and could be an adjuvant treatment in the management of epilepsy. However, autophagy inhibitors also have an anticonvulsant effect. Therefore, the aim of the present mini-review is to discuss the potential role of autophagy in the pathogenesis of epileptogenesis and epilepsy, and how autophagy modulators affect epileptogenesis and epilepsy.<b>Abbreviations:</b> AD: Alzheimer disease; AEDs: antiepileptic drugs; AMPK: adenosine monophosphate-activated protein kinase; ER: endoplasmic reticulum; GABA: gamma aminobutyric acid; HCQ: hydroxycholoroquine; IP<sub>3</sub>: inositol 1,4,5-trisphosphate; NSAID: non-steroidal anti-inflammatory drug; PI3K: phosphoinositide 3-kinase; ROS: reactive oxygen species; SE: status epilepticus; PTZ: pentylenetetrazole; TLE: temporal lobe epilepsy; TSC: tuberous sclerosis complex.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1863-1887"},"PeriodicalIF":14.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12363515/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144082728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AutophagyPub Date : 2025-09-01Epub Date: 2025-05-27DOI: 10.1080/15548627.2025.2509330
Ye Guo, Zhiru Bao, Meiyan Shi, Qiwei Zheng, Yawen Huo, Ran Hu, Yajie Guan, Saiyu Cao, Patrick J Hussey, Xiuxin Deng, Yunjiang Cheng, Pengwei Wang
{"title":"Autophagy plays a dual role in chromoplast transition and degradation and is essential for fruit coloration and ripening.","authors":"Ye Guo, Zhiru Bao, Meiyan Shi, Qiwei Zheng, Yawen Huo, Ran Hu, Yajie Guan, Saiyu Cao, Patrick J Hussey, Xiuxin Deng, Yunjiang Cheng, Pengwei Wang","doi":"10.1080/15548627.2025.2509330","DOIUrl":"10.1080/15548627.2025.2509330","url":null,"abstract":"<p><p>The color of tomato fruits is determined by carotenoids. The process involves removing chloroplast-related components and the biogenesis of chromoplast membranes where carotenoids are stored, but how these events are coordinated is unknown. Here, we demonstrated that part of this mechanism involves macroautophagy/autophagy playing dual roles in chromoplast transition and degradation. We have used fluorescence lifetime imaging microscopy (FLIM) to show that autophagosomes containing chloroplast-derived-vesicles increased significantly during early fruit ripening, which is an essential part of a pathway to the formation of chromoplasts. Interestingly, we also showed that autophagy controls the degradation of the chromoplasts containing carotenoids at the late ripening stage through a process we named chromophagy. This affects fruit color and ABA levels, which were higher in autophagy mutants with a slower turnover of chromoplasts. We concluded that autophagy is a determinant of both fruit coloration and ripening through degrading different plastid-related cargo.<b>Abbreviation</b>: ABA: abscisic acid; ATG: autophagy related; AP: autophagosome; BR: breaker stage; BR + 3: 3 days after breaker stage; BR + 7: 7 days after breaker stage; CV: coefficient of variation; FLIM: fluorescence lifetime imaging microscopy; IG: immature green; LR: light red; MG: mature green; PDVs: plastid-derived-vesicles; RhB: rhodamine B; RNAi: RNA interference; RR: ripe red; TEM: transmission electron microscopy; WLL: white-light laser.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"2058-2068"},"PeriodicalIF":14.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12363503/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144112991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AutophagyPub Date : 2025-09-01Epub Date: 2025-04-04DOI: 10.1080/15548627.2025.2483887
Yi-Tian Ying, Jing Yang, Hui-Wen Ye, Mei-Yi Chen, Xia Liu, Wei Chen, Jin-Xin Xu, Xun Tan
{"title":"<i>Staphylococcus aureus</i> reprograms CASP8 (caspase 8) signaling to evade cell death and Xenophagy.","authors":"Yi-Tian Ying, Jing Yang, Hui-Wen Ye, Mei-Yi Chen, Xia Liu, Wei Chen, Jin-Xin Xu, Xun Tan","doi":"10.1080/15548627.2025.2483887","DOIUrl":"10.1080/15548627.2025.2483887","url":null,"abstract":"<p><p>Regulated cell death and xenophagy constitute fundamental cellular mechanisms against invading microorganisms. <i>Staphylococcus aureus</i>, a notorious pathogen, can invade and persist within host cells for extended periods. Here, we describe a novel mechanism by which <i>S. aureus</i> subverts these host defenses through the manipulation of the CASP8 (caspase 8) signaling pathway. Upon invasion, <i>S. aureus</i> triggers the assembly of a RIPK3 (receptor interacting serine/threonine kinase 3) complex to induce CASP8 autoprocessing. However, the bacterium inhibits CUL3 (cullin 3)-dependent K63-linked ubiquitination, leading to an atypical activation of CASP8. This non-canonical activation does not initiate the CASP8-CASP3 cascade but instead suppresses RIPK3-dependent necroptosis, a regulated cell death pathway typically activated when apoptosis fails. The resulting non-apoptotic, cleaved CASP8 redirects its enzymatic activity toward cleaving SQSTM1/p62, a selective macroautophagy/autophagy receptor, thus enabling <i>S. aureus</i> to evade antimicrobial xenophagy. The results of this study suggest that <i>S. aureus</i> reprograms the CASP8 signaling pathway from inducing cell death to preserving cell survival and inhibiting xenophagy, a critical strategy that supports its stealthy replication and persistence within host cells.<b>Abbreviations</b>: CASP3: caspase 3; CASP8: caspase 8; CFU: colony-forming units; CUL3: cullin 3; DUB: deubiquitinating enzyme; MAP1LC3B-II/LC3B-II: microtubule associated protein 1 light chain 3 beta-II; MOI: multiplicity of infection; RIPK1: receptor interacting protein kinase 1; RIPK3: receptor interacting protein kinase 3; <i>S. aureus</i>: <i>Staphylococcus aureus</i>.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1962-1975"},"PeriodicalIF":14.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12366813/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143722980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AutophagyPub Date : 2025-09-01Epub Date: 2025-05-09DOI: 10.1080/15548627.2025.2498506
Martin P Schwalm, Christopher Lenz, Krishna Saxena, Daniel J Klionsky, Ewgenij Proschak, Stefan Knapp
{"title":"Biochemical investigation of LC3/GABARAP-ligand interaction as an important quality measure for LC3/GABARAP-targeting small molecules: addendum to the guidelines (4th edition).","authors":"Martin P Schwalm, Christopher Lenz, Krishna Saxena, Daniel J Klionsky, Ewgenij Proschak, Stefan Knapp","doi":"10.1080/15548627.2025.2498506","DOIUrl":"10.1080/15548627.2025.2498506","url":null,"abstract":"<p><p>Targeted protein degradation (TPD) represents a new therapeutic modality that allows the targeting of proteins that are considered undruggable by conventional small molecules. While TPD approaches via the ubiquitin-proteasome system are well established and validated, additional degradation pathways still require rigorous characterization. Here, we focus on macroautophagy/autophagy tethering compounds, a class of small molecules, designed to recruit cargo to LC3/GABARAP proteins for subsequent autophagosome-dependent degradation. We provide guidance for the biophysical and structural characterization of small molecule modulators for studying LC3/GABARAP-ligand interactions. In addition, we discuss potential limitations of autophagy-based TPD systems and emphasize the need for rigorous quality control in the development of LC3/GABARAP-targeting small molecules.<b>Abbreviations</b>: DSF: differential scanning fluorimetry; FP: fluorescence polarization; FRET: Förster/fluorescence resonance energy transfer; HTRF: homogeneous time-resolved fluorescence; ITC: isothermal titration calorimetry; LIR: LC3-interacting region; MGs: molecular glues; NMR: nuclear magnetic resonance; PROTACs: PROteolysis-TArgeting Chimeras; SPR: surface plasmon resonance; TPD: targeted protein degradation; TR-FRET: time-resolved Förster/fluorescence resonance energy transfer; UPS: ubiquitin-proteasome system.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"2069-2073"},"PeriodicalIF":14.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12363526/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144065364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AutophagyPub Date : 2025-09-01Epub Date: 2025-06-01DOI: 10.1080/15548627.2025.2508934
Susan Ferro-Novick
{"title":"Endoplasmic reticulum tubule junctions are sites of autophagy.","authors":"Susan Ferro-Novick","doi":"10.1080/15548627.2025.2508934","DOIUrl":"10.1080/15548627.2025.2508934","url":null,"abstract":"<p><p>Selective endoplasmic reticulum (ER) macroautophagy/autophagy, also called reticulophagy, is a disposal pathway that degrades ER domains. A major role of reticulophagy is the removal of ER domains that contain misfolded proteins resistant to ER-associated degradation (ERAD). Our studies have shown that RTN3L, the SEC24C-SEC23 COPII coat subcomplex, and the CUL3<sup>KLHL12</sup> E3 ligase that ubiquitinates RTN3L targets ERAD-resistant misfolded protein condensates for degradation at ER-reticulophagy sites (ERPHS), autophagic sites that form at tubule junctions. Unexpectedly, we found that the Parkinson disease protein PINK1 regulates ER tubulation. Loss of PINK1 disrupts the formation of peripheral tubule junctions, and, as a consequence, reticulophagy is blocked and misfolded proteins accumulate in the ER. Overexpression of the ER tubulating domain of DNM1L/DRP1, a multifunctional PINK1 kinase substrate that localizes to ER-mitochondria contact sites, increases junctions and restores reticulophagy. Our findings show that PINK1 shapes the ER to target misfolded proteins for RTN3L-SEC24C-mediated macroreticulophagy at defined ER sites, peripheral tubule junctions.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"2080-2081"},"PeriodicalIF":14.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12363496/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144144842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AutophagyPub Date : 2025-09-01Epub Date: 2025-04-20DOI: 10.1080/15548627.2025.2487036
Pablo J Tapia, José A Martina, Pablo S Contreras, Akriti Prashar, Eutteum Jeong, Dominic De Nardo, Rosa Puertollano
{"title":"TFEB and TFE3 regulate STING1-dependent immune responses by controlling type I interferon signaling.","authors":"Pablo J Tapia, José A Martina, Pablo S Contreras, Akriti Prashar, Eutteum Jeong, Dominic De Nardo, Rosa Puertollano","doi":"10.1080/15548627.2025.2487036","DOIUrl":"10.1080/15548627.2025.2487036","url":null,"abstract":"<p><p>STING1 is an essential component of the innate immune defense against a wide variety of pathogens. Whereas induction of type I interferon (IFN) responses is one of the best-defined functions of STING1, our transcriptomic analysis revealed IFN-independent activities of STING1 in macrophages, including transcriptional upregulation of numerous lysosomal and autophagic genes. This upregulation was mediated by the STING1-induced activation of the transcription factors TFEB and TFE3, and led to increased autophagy, lysosomal biogenesis, and lysosomal acidification. TFEB and TFE3 also modulated IFN-dependent STING1 signaling by controlling IRF3 activation. IFN production and cell death were increased in TFEB- and TFE3-depleted iBMDMs. Conversely, TFEB overexpression led to reduced IRF3 activation and an almost complete inhibition of IFN synthesis and secretion, resulting in decreased CASP3 activation and increased cell survival. Our study reveals a key role of TFEB and TFE3 as regulators of STING1-mediated innate antiviral immunity.<b>Abbreviation:</b> ACOD1/IRG1, aconitate decarboxylase 1; cGAMP, cyclic guanosine monophosphate-adenosine monophosphate; CGAS, cyclic GMP-AMP synthase; DMXAA, 5,6-dimethylxanthenone-4-acetic acid; EIF4EBP1, eukaryotic translation initiation factor 4E binding protein 1; GABARAP, GABA type A receptor-associated protein; HSV-1, herpes simplex virus type; iBMDMs, immortalized bone marrow-derived macrophages; IFN, type I interferon; IFNB, interferon beta; IKBKE, inhibitor of nuclear factor kappa B kinase subunit epsilon; IRF3, interferon regulatory factor 3; LAMP1, lysosomal associated membrane protein 1; LAMP2, lysosomal associated membrane protein 2; MTORC1, mechanistic target of rapamycin kinase complex 1; RPS6, ribosomal protein S6; STING1, stimulator of interferon response cGAMP interactor 1; TBK1, TANK binding kinase 1; TFE3, transcription factor binding to IGHM enhancer 3; TFEB, transcription factor EB.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"2028-2045"},"PeriodicalIF":14.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12363505/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143805130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}