Autophagy最新文献

{"title":"Reconsidering the selectivity of bulk autophagy: cargo hitchhiking specifies cargo for degradation.","authors":"Eigo Takeda, Alexander I May, Yoshinori Ohsumi","doi":"10.1080/15548627.2024.2447209","DOIUrl":"10.1080/15548627.2024.2447209","url":null,"abstract":"<p><p>Bulk macroautophagy/autophagy, typically induced by starvation, is generally thought to isolate cytosolic components for degradation in a non-selective manner. Despite the fundamental nature of the eukaryotic degradation pathway, the question of what cargo is isolated by autophagy has remained unaddressed for over 30 years. We recently employed mass spectrometry to analyze the contents of isolated autophagic bodies. In the process of these experiments, we uncovered Hab1 (Highly enriched in Autophagic Bodies 1), a novel protein that is delivered extremely preferentially via autophagy. We report that Hab1 is a novel receptor protein, the N-terminus of which binds Atg8-PE, whereas the C-terminus binds ribosomes. Surprisingly, detailed biochemical and microscopic analyses revealed that ribosome-bound Hab1 is preferentially delivered to the vacuole by \"'hitchhiking'\" on phagophores/isolation membranes that form during bulk autophagy. This is a completely different mechanism of cargo selection that differs from previous descriptions of selective autophagy, in which the cargo-specific receptor proteins initiate phagophore membrane formation via scaffold proteins such as Atg11. We propose that cargo hitchhiking allows for the specification of cargo during bulk autophagy, which is otherwise a non-selective process.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"910-911"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11925106/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142901034","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}

{"title":"CKAP4 in hepatocellular carcinoma: competitive RETREG1/FAM134B binding, reticulophagy regulation, and cancer progression.","authors":"Jie Mo, Chen Su, Pengcheng Li, Zhenhua Yang, Ran Tao, Qiumeng Liu, Chaoyi Yuan, Lei Xu, Qianyun Ge, Deng Ning, Huifang Liang, Haidan Zhu, Yan Luo, Xiaoping Chen, Jin Chen, Bixiang Zhang","doi":"10.1080/15548627.2024.2435236","DOIUrl":"10.1080/15548627.2024.2435236","url":null,"abstract":"<p><p>RETREG1/FAM134B is known for its role as a reticulophagy receptor. Our previous study established that RETREG1 is upregulated in hepatocellular carcinoma (HCC) and contributes to disease progression by activating the AKT signaling pathway. However, the specific mechanisms underlying the elevated expression of RETREG1 in HCC remain unclear. This study unveils the interaction of RETREG1 with CKAP4 and TRIM21. We demonstrated that TRIM21 ubiquitinates RETREG1 at K247 and K252, facilitating its proteasomal degradation. Conversely, CKAP4 shields RETREG1 from degradation by competitively binding to it, revealing a novel post-translational modification mechanism for RETREG1. By modulating RETREG1 expression, CKAP4, and TRIM21 intricately regulate reticulophagy. Additionally, we observed that stress-induced TRIM21 upregulation mitigates the function of RETREG1 to restore ER stress equilibrium. The oncogenic potential of CKAP4 in HCC was demonstrated using various animal models. Clinical sample analyses suggested that CKAP4 is a potential biomarker for HCC prognosis and diagnosis.<b>Abbreviation</b>: AKT: thymoma viral proto-oncogene; aa: amino acid; bp: base pair; CHX: cycloheximide; co-IP: co-Immunoprecipitation; CQ: chloroquine; CKAP4: cytoskeleton-associated protein 4; DKK1: dickkopf WNT signaling pathway inhibitor 1; DUBs: deubiquitinating enzymes; EBSS: Earle's balanced salt solution; EGFP: enhanced green fluorescent protein; ER: endoplasmic reticulum; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GFP: green fluorescent protein; HCC: hepatocellular carcinoma; HFD: high-fat diet; HiTV: hyperdynamic tail vein injection; IF: immunofluorescence; IHC: immunohistochemistry; IP-MS: immunoprecipitation-mass spectrometry; LIR: LC3-interacting region; mAbs: monoclonal antibodies; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; mCherry: monomeric cherry; oe: overexpression; PDX: patient-derived tumor xenograft; reticulophagy: endoplasmic reticulum selective autophagy; RETREG1: reticulophagy regulator 1; RHD: reticulon-homology domain; Tg: thapsigargin; Tm: tunicamycin; TRIM21: tripartite motif-containing 21; UB: ubiquitin; WT: wild-type.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"840-859"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11925109/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142848383","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}

{"title":"Autophagy controls neuronal differentiation by regulating the WNT-DVL signaling pathway.","authors":"Vincencius Vidyawan, Lesly Puspita, Virginia Blessy Juwono, Magdalena Deline, Kelvin Pieknell, Mi-Yoon Chang, Sang-Hun Lee, Jae-Won Shim","doi":"10.1080/15548627.2024.2407707","DOIUrl":"10.1080/15548627.2024.2407707","url":null,"abstract":"<p><p>Macroautophagy/autophagy dysregulation is associated with various neurological diseases, including Vici syndrome. We aimed to determine the role of autophagy in early brain development. We generated neurons from human embryonic stem cells and developed a Vici syndrome model by introducing a loss-of-function mutation in the <i>EPG5</i> gene. Autophagy-related genes were upregulated at the neuronal progenitor cell stage. Inhibition of autolysosome formation with bafilomycin A₁ treatment at the neuronal progenitor cell stage delayed neuronal differentiation. Notably, WNT (Wnt family member) signaling may be part of the underlying mechanism, which is negatively regulated by autophagy-mediated DVL2 (disheveled segment polarity protein 2) degradation. Disruption of autolysosome formation may lead to failure in the downregulation of WNT signaling, delaying neuronal differentiation. <i>EPG5</i> mutations disturbed autolysosome formation, subsequently inducing defects in progenitor cell differentiation and cortical layer generation in organoids. Disrupted autophagy leads to smaller organoids, recapitulating Vici syndrome-associated microcephaly, and validating the disease relevance of our study.<b>Abbreviations</b>: BafA1: bafilomycin A1; co-IP: co-immunoprecipitation; DVL2: dishevelled segment polarity protein 2; EPG5: ectopic P-granules 5 autophagy tethering factor; gRNA, guide RNA; hESC: human embryonic stem cells; KO: knockout; mDA, midbrain dopamine; NIM: neural induction media; NPC: neuronal progenitor cell; qPCR: quantitative polymerase chain reaction; UPS: ubiquitin-proteasome system; WNT: Wnt family member; WT: wild type.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"719-736"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142395879","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}

{"title":"Impaired chaperone-mediated autophagy leads to abnormal SORT1 (sortilin 1) turnover and CES1-dependent triglyceride hydrolysis.","authors":"You-Jin Choi, Yoon Ah Nam, Ji Ye Hyun, Jihyeon Yu, Yewon Mun, Sung Ho Yun, Wonseok Lee, Cheon Jun Park, Byung Woo Han, Byung-Hoon Lee","doi":"10.1080/15548627.2024.2435234","DOIUrl":"10.1080/15548627.2024.2435234","url":null,"abstract":"<p><p>SORT1 (sortilin 1), a member of the the Vps10 (vacuolar protein sorting 10) family, is involved in hepatic lipid metabolism by regulating very low-density lipoprotein (VLDL) secretion and facilitating the lysosomal degradation of CES1 (carboxylesterase 1), crucial for triglyceride (TG) breakdown in the liver. This study explores whether SORT1 is targeted for degradation by chaperone-mediated autophagy (CMA), a selective protein degradation pathway that directs proteins containing KFERQ-like motifs to lysosomes via LAMP2A (lysosomal-associated membrane protein 2A). Silencing LAMP2A or HSPA8/Hsc70 with siRNA increased cytosolic SORT1 protein levels. Leupeptin treatment induced lysosomal accumulation of SORT1, unaffected by si<i>LAMP2A</i> co-treatment, indicating CMA-dependent degradation. Human SORT1 contains five KFERQ-like motifs (₆₅₈VVTKQ₆₆₂, ₇₃₀VREVK₇₃₄, ₇₃₃VKDLK₇₃₇, ₇₃₄KDLKK₇₃₈, and ₇₃₅DLKKK₇₃₉), crucial for HSPA8 recognition; mutating any single amino acid within these motifs decreased HSPA8 binding. Furthermore, compromised CMA activity resulted in elevated SORT1-mediated degradation of CES1, contributing to increased lipid accumulation in hepatocytes. Consistent with <i>in vitro</i> findings, LAMP2A knockdown in mice exacerbated high-fructose diet-induced fatty liver, marked by increased SORT1 and decreased CES1 levels. Conversely, LAMP2A overexpression promoted SORT1 degradation and CES1D accumulation, counteracting fasting-induced CES1D suppression through CMA activation. Our findings reveal that SORT1 is a substrate of CMA, highlighting its crucial role in directing CES1 to lysosomes. Consequently, disrupting CMA-mediated SORT1 degradation significantly affects CES1-dependent TG hydrolysis, thereby affecting hepatic lipid homeostasis.<b>Abbreviations</b>: APOB: apolipoprotein B; CES1: carboxylesterase 1; CMA: chaperone-mediated autophagy; HSPA8/Hsc70: heat shock protein family A (Hsp70) member 8; LAMP2A: lysosomal associated membrane protein 2A; LDL-C: low-density lipoprotein-cholesterol; PLIN: perilipin; SORT1: sortilin 1; TG: triglyceride; VLDL: very low-density lipoprotein; Vps10: vacuolar protein sorting 10.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"827-839"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11925108/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142752380","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}

{"title":"Identification of the mammalian VPS4A as a selective lipophagy receptor.","authors":"Dimitra Dialynaki, Daniel J Klionsky","doi":"10.1080/15548627.2024.2441535","DOIUrl":"10.1080/15548627.2024.2441535","url":null,"abstract":"<p><p>Lipophagy is a selective type of autophagy where lipid droplets are targeted to the lysosome/vacuole for degradation. Even though lipophagy has been reported in various species, many questions remain unaddressed. How are the lipid droplets sequestered to the lysosome? What is the lipophagy receptor? How is this receptor regulated at a posttranslational level? A new collaborative study among several universities conducted on mouse and human hepatocytes sheds light on these questions, deciphering the lipophagy mechanism in the liver. In a recent paper, Das and colleagues identified VPS4A (vacuolar protein sorting 4 homolog A) as a selective receptor, providing new insights into the mechanistic pathway of lipophagy in mammals and its inverse association with steatotic liver diseases.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"691-692"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11925104/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142901119","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}

{"title":"Efficient PHB2 (prohibitin 2) exposure during mitophagy depends on VDAC1 (voltage dependent anion channel 1).","authors":"Moumita Roy, Sumangal Nandy, Elena Marchesan, Chayan Banerjee, Rupsha Mondal, Federico Caicci, Elena Ziviani, Joy Chakraborty","doi":"10.1080/15548627.2024.2426116","DOIUrl":"10.1080/15548627.2024.2426116","url":null,"abstract":"<p><p>Exposure of inner mitochondrial membrane resident protein PHB2 (prohibitin 2) during autophagic removal of depolarized mitochondria (mitophagy) depends on the ubiquitin-proteasome system. This uncovering facilitates the PHB2 interaction with phagophore membrane-associated protein MAP1LC3/LC3. It is unclear whether PHB2 is exposed randomly at mitochondrial rupture sites. Prior knowledge and initial screening indicated that VDAC1 (voltage dependent anion channel 1) might play a role in this phenomenon. Through <i>in vitro</i> biochemical assays and imaging, we have found that VDAC1-PHB2 interaction increases during mitochondrial depolarization. Subsequently, this interaction enhances the efficiency of PHB2 exposure and mitophagy. To investigate the relevance <i>in vivo</i>, we utilized <i>porin</i> (equivalent to VDAC1) knockout <i>Drosophila</i> line. Our findings demonstrate that during mitochondrial stress, porin is essential for Phb2 exposure, Phb2-Atg8 interaction and mitophagy. This study highlights that VDAC1 predominantly synchronizes efficient PHB2 exposure through mitochondrial rupture sites during mitophagy. These findings may provide insights to understand progressive neurodegeneration.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"897-909"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142607141","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}

{"title":"AMPK protects proximal tubular epithelial cells from lysosomal dysfunction and dedifferentiation induced by lipotoxicity.","authors":"Louise Pierre, Florian Juszczak, Valentine Delmotte, Morgane Decarnoncle, Benjamin Ledoux, Laurent Bultot, Luc Bertrand, Marielle Boonen, Patricia Renard, Thierry Arnould, Anne-Emilie Declèves","doi":"10.1080/15548627.2024.2435238","DOIUrl":"10.1080/15548627.2024.2435238","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Renal proximal tubules are a primary site of injury in metabolic diseases. In obese patients and animal models, proximal tubular epithelial cells (PTECs) display dysregulated lipid metabolism, organelle dysfunctions, and oxidative stress that contribute to interstitial inflammation, fibrosis and ultimately end-stage renal failure. Our research group previously pointed out AMP-activated protein kinase (AMPK) decline as a driver of obesity-induced renal disease. Because PTECs display high macroautophagic/autophagic activity and rely heavily on their endo-lysosomal system, we investigated the effect of lipid stress on autophagic flux and lysosomes in these cells. Using a model of highly differentiated primary PTECs challenged with palmitate, our data placed lysosomes at the cornerstone of the lipotoxic phenotype. As soon as 6 h after palmitate exposure, cells displayed impaired lysosomal acidification subsequently leading to autophagosome accumulation and activation of lysosomal biogenesis. We also showed the inability of lysosomal quality control to restore acidic pH which finally drove PTECs dedifferentiation. When palmitate-induced AMPK activity decline was prevented by AMPK activators, lysosomal acidification and the differentiation profile of PTECs were preserved. Our work provided key insights on the importance of lysosomes in PTECs homeostasis and lipotoxicity and demonstrated the potential of AMPK in protecting the organelle from lipid stress.&lt;b&gt;Abbreviation&lt;/b&gt;: ACAC: acetyl-CoA carboxylase; ACTB: actin beta; AICAR: 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside; AMPK: AMP-activated protein kinase; APQ1: aquaporin 1 (Colton blood group); BSA: bovine serum albumin; CDH16: cadherin 16; CKD: chronic kidney disease; CTSB: cathepsin B; CTSD: cathepsin D; EPB41L5: erythrocyte membrane protein band 4.1 like 5; EIF4EBP1: eukaryotic translation initiation factor 4E binding protein 1; EMT: epithelial-to-mesenchymal transition; FA: fatty acid; FCCP: carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone; GFP: green fluorescent protein; GUSB: glucuronidase beta; HEXB: hexosaminidase subunit beta; LAMP: lysosomal associated membrane protein; LD: lipid droplet; LGALS3: galectin 3; LLOMe: L-leucyl-L-leucine methyl ester hydrobromide; LMP: lysosomal membrane permeabilization; LRP2: LDL receptor related protein 2; LSD: lysosomal storage disorder; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MCOLN1: mucolipin TRP cation channel 1; MG132: N-benzyloxycarbonyl-L-leucyl-L-leucyl-L-leucinal; MmPTECs: Mus musculus (mouse) proximal tubular epithelial cells; MTORC1: mechanistic target of rapamycin kinase complex 1; OA: oleate; PA: palmitate; PIKFYVE: phosphoinositide kinase, FYVE-type zinc finger containing; PTs: proximal tubules; PTECs: proximal tubular epithelial cells; PRKAA: protein kinase AMP-activated catalytic subunit alpha; RFP: red fluorescent protein; RPS6KB: ribosomal protein S6 kinase B; SLC5A2: solute carrier family 5 member 2; ","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"860-880"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11925112/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142831025","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}

{"title":"Upregulation of ISG15 induced by MAPT/tau accumulation represses autophagic flux by inhibiting HDAC6 activity: a vicious cycle in Alzheimer disease.","authors":"Qian Liu, Xin Wang, Zhi-Ting Fang, Jun-Ning Zhao, Xue-Xiang Rui, Bing-Ge Zhang, Ye He, Rui-Juan Liu, Jian Chen, Gao-Shang Chai, Gong-Ping Liu","doi":"10.1080/15548627.2024.2431472","DOIUrl":"10.1080/15548627.2024.2431472","url":null,"abstract":"<p><p>Alzheimer disease (AD), a prevalent neurodegenerative condition in the elderly, is marked by a deficit in macroautophagy/autophagy, leading to intracellular MAPT/tau accumulation. While ISG15 (ISG15 ubiquitin like modifier) has been identified as a regulator of selective autophagy in ataxia telangiectasia (A-T), its role in AD remains unexplored. Our study reveals elevated ISG15 levels in the brains of patients with sporadic AD and AD models <i>in vivo</i> and <i>in vitro</i>. ISG15 overexpression in cells and the hippocampus inhibited HDAC6 (histone deacetylase 6) activity through C-terminal LRLRGG binding to HDAC6. Consequently, this increased CTTN (cortactin) acetylation, disrupted CTTN and F-actin recruitment to lysosomes, and impaired autophagosome (AP)-lysosome (LY) fusion. These disruptions led to MAPT/tau accumulation, synaptic damage, neuronal loss, and cognitive deficits. Conversely, ISG15 knockdown in our HsMAPT (human MAPT) pathology model restored HDAC6 activity, promoted AP-LY fusion, and improved cognitive function. This study identifies ISG15 as a key regulator of autophagic flux in AD, suggesting that targeting ISG15-mediated autophagy could offer therapeutic potential for AD.<b>Abbreviation</b>: AAV: adeno-associated virus; AD: Alzheimer disease; ALP: autophagy-lysosomal pathway; ANOVA: analysis of variance; AP: autophagosome; BafA1: bafilomycin A₁; CHX: cycloheximide; CQ: chloroquine; CTTN: cortactin; FC: fear conditioning; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GRIN/NMDARs: N-methyl-D-aspartate glutamate ionotropic receptor NMDA types; HDAC6: histone deacetylase 6; HEK293: human embryonic kidney 293; HsMAPT: human MAPT; IF: immunofluorescence; IHC: immunohistochemistry; IP: immunoprecipitation; ISG15: ISG15 ubiquitin like modifier; LAMP1: lysosomal associated membrane protein 1; LY: lysosome; MAPT: microtubule associated protein tau; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MWM: Morris water maze; NOR: novel object recognition; SQSTM1/p62: sequestosome 1; ZnF UBP: zinc finger ubiquitin-binding protein.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"807-826"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11925114/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788088","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}

{"title":"Chaperone-mediated autophagy degrades SERPINA1^E342K/α1-antitrypsin Z variant and alleviates cell stress.","authors":"Jiayu Lin, Xinyue Wei, Yan Dai, Haorui Lu, Yajian Song, Jiansong Ju, Rihan Wu, Qichen Cao, Hao Yang, Lang Rao","doi":"10.1080/15548627.2025.2480037","DOIUrl":"10.1080/15548627.2025.2480037","url":null,"abstract":"<p><p>Chaperone-mediated autophagy (CMA) is a specific form of autophagy that selectively targets proteins containing a KFERQ-like motif and relies on the chaperone protein HSPA8/HSC70 for substrate recognition. In SERPINA1/a1-antitrypsin deficiency (AATD), a disease characterized by the hepatic buildup of the SERPINA1^E342K/ATZ, CMA's role had been unclear. This work demonstrates the critical role that CMA plays in preventing SERPINA1^E342K/ATZ accumulation; suppressing CMA worsens SERPINA1^E342K/ATZ accumulation while activating it through chemical stimulation or LAMP2A overexpression promotes SERPINA1^E342K/ATZ breakdown. Specifically, SERPINA1^E342K/ATZ's ₁₂₁QELLR₁₂₅ motif is critical for HSPA8/HSC70 recognition and LAMP2A's charged C-terminal cytoplasmic tail is vital for substrate binding, facilitating CMA-mediated degradation of SERPINA1^E342K/ATZ. This selective activation of CMA operates independently of other autophagy pathways and alleviates SERPINA1^E342K/ATZ aggregate-induced cellular stress. In vivo administration of AR7 promotes hepatic SERPINA1^E342K/ATZ elimination and mitigates hepatic SERPINA1^E342K/ATZ aggregation pathology. These findings highlight CMA's critical function in cellular protein quality control of SERPINA1^E342K/ATZ and place it as a novel target for AATD treatment.<b>Abbreviation:</b> AR7: atypical retinoid 7; ATG16L1: autophagy related 16 like 1; AATD: SERPINA1/alpha-1 antitrypsin deficiency; CHX: cycloheximide; CMA: chaperone-mediated autophagy; CQ: chloroquine; ER: endoplasmic reticulum; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HSPA8/HSC70: heat shock protein family A (Hsp70) member 8; LAMP2A: lysosomal associated membrane protein 2A; LAMP2B: lysosomal associated membrane protein 2B; LAMP2C: lysosomal associated membrane protein 2C; MG132: carbobenzoxy-L-leucyl-L-leucyl-L-leucinal; PAS-D: periodic acid-Schiff plus diastase; SERPINA1/A1AT: serpin family A member 1; SERPINA1^E342K/ATZ: Z variant of SERPINA1; TMRE: tetramethyl rhodamine ethyl ester perchlorate.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-18"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671496","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}

{"title":"RHOD mediates ATG9A trafficking to promote autophagosome formation during autophagy in cancer.","authors":"Sijia Wang, Jing Ren, Jinghan Chi, Yifei Guan, Ran Zheng, Juan Wang, Xinhui Liu, Hua Huang","doi":"10.1080/15548627.2025.2484604","DOIUrl":"10.1080/15548627.2025.2484604","url":null,"abstract":"<p><p>ATG9A is a transmembrane protein essential for macroautophagy/autophagy that drives autophagosome formation by delivering essential proteins and lipids to the phagophore through vesicle trafficking. Here, we demonstrate that the atypical Rho GTPase RHOD is required for ATG9A trafficking and stimulates autophagosome formation. Upon starvation, RHOD interacted with ATG9A and accompanied ATG9A trafficking from the Golgi toward phagophores. In addition, starvation-induced high levels of RHOD resulted in Golgi fragmentation to further promote ATG9A vesicle export from the trans-Golgi network to the peripheral region. Loss of RHOD suppressed ATG9A trafficking and reduced the distribution of ATG9A on the phagophore. Moreover, WHAMM (WASP homolog associated with actin, golgi membranes and microtubules) forms a complex with RHOD and participates in this process in a RHOD-dependent manner. Importantly, RHOD mutants, which lack the exon II-containing effector region motif that is required for ATG9A binding or lack the CAAX box that is responsible for membrane targeting, fail to stimulate ATG9A trafficking and autophagosome formation. Furthermore, RHOD plays a distinct suppressor role in tumor development, partly associated with its regulatory effect on autophagy. These findings reveal the important roles of RHOD in autophagy and tumor development.<b>Abbreviation</b>: ATG9A: autophagy related 9A; BafA1: bafilomycin A₁; BiFC: bimolecular fluorescence complementation; co-IP: co-immunoprecipitation; EBSS: Earle's balanced salt solution; FM: full culture medium; KO: knockout; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; PUP-IT: pupylation-based interaction tagging; RHOD: ras homolog family member D; SQSTM1: sequestosome 1; TGN: trans-Golgi network; VC: Venus C-terminal; VN: Venus N-terminal; WHAMM: WASP homolog associated with actin, golgi membranes and microtubules; WIPI2: WD repeat domain, phosphoinositide interacting 2; WT: wild-type; 3-MA: phosphatidylinositol 3-kinase (PtdIns3K) inhibitor 3-methyladenine.</p>","PeriodicalId":93893,"journal":{"name":"Autophagy","volume":" ","pages":"1-19"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143722986","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}