bims-auttor Biomed News
on Autophagy and mTOR
Issue of 2026–11–01
28 papers selected by
Viktor Korolchuk, Newcastle University



  1. Autophagy. 2026 Oct 28. 1-14
      The condition of having a healthy, functional proteome is known as protein homeostasis, or proteostasis. Establishing and maintaining proteostasis is the province of the proteostasis network, a highly interconnected system of over 3000 components that regulate protein synthesis, folding, localization, and degradation. The proteostasis network is a fundamental functional unit in biology that is essential for cellular health and has direct relevance to many diseases of protein conformation. However, it is not well defined or annotated, hindering its functional characterization in health and disease. In this series of manuscripts, we aim to operationally define the human proteostasis network by providing a comprehensive, annotated list of its components. In the other manuscripts in this series, we survey the components of the proteostasis network that make up (1) the machineries for protein synthesis, protein folding, protein trafficking into and out of organelles, and organelle-specific degradation pathways and (2) the ubiquitin-proteasome system. Here, we have compiled a curated list of over 850 unique high-confidence components of the autophagy-lysosome pathway, the other major protein degradation system in human cells. This resource will facilitate the rigorous investigation of autophagy-lysosome pathway dysfunction as a driver of proteostasis imbalance in aging and disease.
    Keywords:  Aging; annotation; degradation; lysosomal catabolism; neurodegenerative disease; systems
    DOI:  https://doi.org/10.1080/15548627.2026.2741038
  2. Front Aging. 2026 ;7 1971981
       Background: Human aging is characterized by a progressive, time-dependent deterioration in physiological and cognitive functioning. Aging is driven by an array of interconnected cellular hallmarks, including genomic instability, mitochondrial dysfunction, telomere attrition, epigenetic alteration and dysfunctional autophagy. Autophagy is a cytoprotective (cellular degradation and recycling) pathway that maintains homeostasis during starvation or stress, and whose activity is associated with extended lifespan. This multi-step process comprises autophagosome formation and maturation, autophagosome-lysosome fusion, and cargo degradation. Thus, analysis of autophagy flux is necessary to precisely design therapeutic interventions aimed at restoring autophagy in aging.
    Methods: The autophagy flux was comprehensively analyzed in human skin fibroblasts from donors of different ages (20-96 years old), a cell system that retains age-associated cellular and molecular signatures. The subcellular localization and activity of the master transcription factor of autophagy and lysosome biogenesis, TFEB, was analyzed by confocal microscopy assays and transcriptional expression of TFEB target genes (RT-qPCR) respectively. The autophagy flux was evaluated by monitoring the autophagy markers LC3 and p62 by Western blotting and confocal microscopy analyses, using inhibitor drugs to block autophagy or lysosomal activity. Autophagosome maturation and autophagosome-lysosome fusion were analyzed by colocalizing LC3 with Sintaxin-17 and LC3 with the lysosomal protein LAMP1 respectively, using inhibitor drugs and confocal microscopy assays. The analysis of lysosomal morphology and function was evaluated by lysobrite dye staining and live-cell confocal microscopy analysis.
    Results: The initial stages of autophagy, including activation of TFEB, and autophagosome formation, remained apparently functional in fibroblast aging. In contrast, the rate of both autophagosome maturation and autophagosome-lysosome fusion, as well as the lysosomal function appears to be altered in aged fibroblasts. Specifically, enlarged dysfunctional lysosomes were identified as a hallmark of the fibroblasts of the 96-year-old donor. This lysosomal dysfunction may lead to a reduced ability to degrade canonical autophagy markers, LC3-II and p62, and the accumulation of lipofuscin.
    Conclusion: Overall, the results provide evidence that autophagy flux is impaired at the late stages in aged fibroblasts, specifically in autophagosome maturation and autophagosome-lysosome fusion steps. Furthermore, it was demonstrated that this failure correlates with the presence of enlarged dysfunctional lysosomes. This study underscores the significance of enhancing lysosomal activity to counteract autophagy decline in aging.
    Keywords:  aging; autophagosomes; autophagy flux; fibroblast aging; lysosomes
    DOI:  https://doi.org/10.3389/fragi.2026.1971981
  3. Autophagy. 2026 Oct 31. 1-3
      Macroautophagy/autophagy maintains cellular homeostasis by delivering cytoplasmic cargo to lysosomes for degradation. Autophagosome formation requires a substantial supply of phospholipids, mainly supported by the lipid scramblase ATG9A and lipid-transfer proteins ATG2A and ATG2B. Our recent study shows that loss of these proteins also alters small extracellular vesicle (sEV) secretion and composition. Cells lacking ATG9A or ATG2A/B release more sEVs during lysosomal inhibition, yet these vesicles contain less microtubule-associated protein 1A/1B-light chain 3 (LC3) and canonical autophagy cargo receptors. These changes are accompanied by impaired amphisome formation and extensive remodeling of the cellular lipidome. Our findings suggest that ATG9A and ATG2A/B coordinate membrane and cargo distribution between autophagy and endosomal secretion, raising the possibility that disrupted lipid supply to autophagosomes redirects lipids toward extracellular vesicle (EV) biogenesis.
    Keywords:  ATG2A/B; ATG9A; Amphisomes; extracellular vesicles; lipid homeostasis
    DOI:  https://doi.org/10.1080/15548627.2026.2752748
  4. Autophagy. 2026 Oct 25.
      Although ubiquitination is required for the recognition of invading bacteria by selective autophagy receptors and subsequent lysosomal destruction (xenophagy), how the host ubiquitin machinery is recruited to intracellular pathogens remains incompletely understood. In our recent study, we revealed that mitochondrial injury serves as an indispensable licensing checkpoint for antibacterial xenophagy. Outer mitochondrial membrane rupture externalizes inner membrane-anchored PHB2/prohibitin 2, which tethers damaged mitochondria to bacteria by engaging PHB (prohibitin) domain-containing proteins on the bacterial cell wall. Concurrently, PHB2 recruits the E3 ligase ARIH1 (ariadne RBR E3 ubiquitin protein ligase 1) or PRKN/Parkin - two well-characterized mitophagy-associated enzymes - which undergo auto-ubiquitination to assemble a localized polyubiquitin coat, ultimately driving organelle-bacterial co-autophagy (mito-xenophagy) independent of canonical mitophagy.
    Keywords:  E3 ubiquitin ligase; host-pathogen interaction; innate immunity; intracellular pathogens; organelle-pathogen crosstalk; polyubiquitination; selective autophagy
    DOI:  https://doi.org/10.1080/15548627.2026.2754671
  5. Adv Sci (Weinh). 2026 Oct 29. pii: e78570. [Epub ahead of print]
      Mitophagy is a central mitochondrial quality-control pathway, and its pharmacological activation is considered to be geroprotective. However, its small-molecule activators act indirectly by perturbing metabolism or mitochondrial function, limiting selectivity and increasing toxicity. Here, we describe a chemical biology strategy for activating damage-responsive mitophagy using bifunctional small molecules that couple mitochondrial recognition to the recruitment of the autophagic machinery. We designed and synthesized a focused library of chimeric molecules and identified MG-1 as a lead compound. It had minimal effects on basal autophagy but markedly enhanced autophagic flux and mitochondrial clearance under conditions of mitochondrial stress. Biochemical analyses, together with fluorescence and electron microscopy, showed that MG-1 promotes lysosomal degradation of damaged mitochondria without acting as a direct mitochondrial uncoupler. MG-1 was well tolerated across experimental systems and improved locomotor performance in a zebrafish model of MPTP-induced mitochondrial dysfunction. These findings establish damage-gated small-molecule chimeras as a promising approach for selective control of mitochondrial quality.
    Keywords:  autophagy; bifunctional molecules; damage‐responsive autophagy; drug discovery; medicinal chemistry; mitophagy; neurodegeneration; small‐molecule chimeras
    DOI:  https://doi.org/10.1002/advs.78570
  6. Autophagy. 2026 Oct 26. 1-28
      The retinal pigment epithelium (RPE) sustains lifelong proteostasis under chronic stress, yet how post-mitotic cells activate macroautophagy/autophagy when canonical kinase pathways suppress it remains unresolved. Here we demonstrate that AKT1 (protein kinase B alpha), drives autophagy through a non-canonical transcriptional mechanism triggered by isoform imbalance. In RPE and age-related macular degeneration (AMD) models, AKT2 (protein kinase B beta) hyperactivation destabilizes MTORC2 (mechanistic target of rapamycin complex 2) and engages RPS6KB/S6K (ribosomal protein S6 kinase beta) -mediated IRS-1 (insulin Receptor Substrate 1) inhibition, creating a feedforward autophagic arrest. Compensatory AKT1 activation via MTORC2 phosphorylates TERT (telomerase reverse transcriptase) at serine 824, driving nuclear translocation that is independent of telomere maintenance. In the nucleus, TERT assembles with FOXO3 (forkhead Box O3) and MYC (MYC proto-oncogene, bHLH transcription factor) into a tripartite transcriptional complex that occupies the EIF2AK3/PERK promoter (eukaryotic translation initiation factor 2-alpha kinase 3/ protein kinase R-like endoplasmic reticulum kinase), enabling EIF2AK3 transcriptional activation. This activity converts the unfolded protein response from pro-apoptotic to cytoprotective: EIF2AK3-ATF4 (activating transcription factor 4) signaling promotes core autophagy machinery biogenesis and selective ERphagy through the receptors TEX264 (testis expressed 264) and CCPG1(cell cycle progression 1), which prevents pathological EIF2AK3 clustering and preserves tubular ER architecture in diseased RPE. Using C. elegans phosphorylation-deficient mutants, mouse models and AMD patient iPSC-RPE, we establish that AKT1-mediated TERT phosphorylation is an evolutionarily conserved prerequisite for FOXO/DAF-16 nuclear function and lysosomal homeostasis in post-mitotic cells, offering therapeutic potential through targeted pharmacologic inhibition of AKT2.Abbreviations: ACTB: actin, beta; AKT1: AKT serine/threonine kinase 1; AKT2: AKT serine/threonine kinase 2; ALP: autophagy-lysosomal pathway; AMD: age-related macular degeneration, ATF4: activating transcription factor 4; ATG3: autophagy related 3; ATG4B: autophagy related 4B cysteine peptidase; ATG7: autophagy related 7; CCPG1: cell cycle progression 1; CFH: complement factor H; C57BL/6J: C57 black 6J; DMSO: dimethyl sulfoxide; MYC: MYC proto-oncogene, bHLH transcription factor; EIF2A/eIF2α: eukaryotic translation initiation factor 2A; EIF2AK3/PERK: eukaryotic translation initiation factor 2 alpha kinase 3; ER: endoplasmic reticulum; ERN1/IRE-1α: endoplasmic reticulum to nucleus signaling 1; ERphagy: endoplasmic reticulum-selective autophagy; FOXO1: forkhead box O1; FOXO3: forkhead box O3; iPSC-RPE: induced pluripotent stem cell-derived retinal pigment epithelium; ITGB1/integrin β1: integrin subunit beta 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MAPKAP1/SIN1: MAPK associated protein 1; MTOR: mechanistic target of rapamycin kinase; MTORC1: MTOR complex 1; MTORC2: MTOR complex 2; PBS: phosphate-buffered saline; PI3K: phosphoinositide 3-kinase; RICTOR: RPTOR independent companion of MTOR complex 2; RPE: retinal pigment epithelium; RPTOR: regulatory associated protein of MTOR complex 1; SQSTM1/p62: sequestosome 1; TERT: telomerase reverse transcriptase; TEX264: testis expressed 264, ER-phagy receptor; UPR: unfolded protein response; VCL: vinculin; WT: wild type.
    Keywords:  AKT1; Age-Related Macular Degeneration (AMD); EIF2AK3/PERK-ATF4 signaling; Telomerase Reverse Transcriptase (TERT); autophagy/Erphagy; proteostasis
    DOI:  https://doi.org/10.1080/15548627.2026.2750048
  7. Autophagy. 2026 Oct 29. 1-2
      Hox proteins act as repressors of developmental autophagy in the Drosophila larval fat body. This repression occurs at the transcriptional level and is associated with the preferential positioning of autophagy-related (atg) genes at the nuclear periphery. Notably, this specific spatial localization depends on Hox proteins. Furthermore, Hox-mediated repression of autophagy relies on the nuclear lamina Lamin-C (LamC) protein. Both the Hox protein Ultrabithorax (Ubx) and LamC are preferentially enriched and preferentially interact in the atg-repressive nuclear compartment. Moreover, the Ubx DNA-binding domain is essential for Ubx-LamC interaction and to target atg loci to the nuclear periphery. Altogether, these findings uncover a novel molecular mechanism in which a Hox transcription factor acts as an anchoring molecule, bringing atg genes into a LamC-rich repressive nuclear microenvironment. Here, we describe this mechanism, adress the questions that remain to be explored and discuss its broader implications for other Hox/Lamin-dependent regulatory contexts.Abbreviations: atg: autophagy related genes; FB: fat body; LamC: Lamin-C; L3F:third-instar larval feeding stage; L3W: third-instar larval wanderingstage; Ubx: Ultrabithorax.
    Keywords:  Autophagy related genes; Drosophila; Hox; Lamin-C; fat body; transcription
    DOI:  https://doi.org/10.1080/15548627.2026.2755924
  8. Autophagy. 2026 Oct 27.
      Excess lipid accumulation and a sedentary lifestyle are associated with metabolic dysfunction-associated fatty liver disease (MAFLD), but the causal mechanisms and preventive methods are not fully understood. Macroautophagy/autophagy is a lysosomal degradation pathway robustly induced by exercise and plays a key role in lipid metabolism. Understanding the mechanisms by which exercise activates autophagy and elicits metabolic benefits in the liver will provide important insights into the pathogenesis of MAFLD. Here, we discovered negative correlations between expression and lactylation of WDR41 (WD repeat domain 41) and pathogenesis of a series of human hepatic metabolic diseases. We found that WDR41 was a pro-autophagy protein that underwent lactylation in response to autophagy-inducing conditions, such as exercise. WDR41 was lactylated at lysine 319 (K319), a modification facilitated by LDHA (lactate dehydrogenase A) upon autophagy induction, and delactylated by SIRT2 (sirtuin 2). Lactylated WDR41 promoted autophagy initiation by directly interacting with the autophagy proteins ATG13 (autophagy related 13) and RB1CC1/FIP200 (RB1 inducible coiled-coil 1) and driving the ULK1 (unc-51 like autophagy activating kinase 1) complex assembly. Physiologically, WDR41 and WDR41K319 lactylation, were important for exercise-induced improvements in insulin sensitivity and lipid metabolism against excess lipid accumulation in the liver. Thus, we demonstrated that WDR41 lactylation at K319 is an important regulatory mechanism by which exercise regulates autophagy and hepatic glucose and lipid metabolism.
    Keywords:  Glucose metabolism; MAFLD; ULK1 kinase; hepatic steatosis; insulin sensitivity; lactate; lipid metabolism
    DOI:  https://doi.org/10.1080/15548627.2026.2754683
  9. bioRxiv. 2026 Sep 03. pii: 2026.09.01.748611. [Epub ahead of print]
      Maintenance of cellular homeostasis requires tight coordination between protein synthesis and degradation, particularly at old age and under conditions of stress including starvation. Autophagy contributes to sustain this balance by degrading cytoplasmic proteins and organelles. It thus is essential to prevent the accumulation of damaged proteins and organelles and to recycle nutrients. Of the three forms of autophagy, macroautophagy, chaperone mediated autophagy, and (endosomal) microautophagy (e-MI), the latter remains the least well understood. During e-MI, cytosolic substrate proteins are captured into late endosomes via ESCRT-dependent multivesicular body formation and then degraded in late endosomes or lysosomes. e-MI is thought to contribute to protein quality control under basal conditions and under stress. Importantly, very little is known about the endogenous substrates of e-MI in flies and thus about its physiological role. Performing integrative multi-omic analyses in Drosophila larval fat body that has functions similar to mammalian liver and adipose tissue, we identified 153 high-confidence endogenous e-MI substrates with the degradation of ribosomal proteins by e-MI being the most strongly affected functional category. Generally, we found that starvation caused the depletion of proteins involved in translation, aminoacyl-tRNA synthesis, and ribosomal biogenesis, without affecting their level of transcripts. Importantly, we observe a striking specificity between e-MI and macroautophagy, as the two pathways largely target distinct protein sets including different subsets of ribosomal proteins. Our metabolomic analysis further shows that genetic inhibition of e-MI reverses the reduced levels of amino acid caused by starvation. Together, our findings reveal ribosome turnover as a central physiological function of Drosophila e-MI and establish e-MI as a pathway driving metabolic adaptation during starvation.
    HIGHLIGHTS: Proteomic and metabolomic analysis of Drosophila fat body under starvation stress Systematic identification of endosomal microautophagy (e-MI) substrates.Ribosomal proteins are a major target of e-MI.e-MI and macroautophagy degrade distinct proteins incl. different ribosomal ones.Prolonged starvation alters amino acid levels.
    DOI:  https://doi.org/10.64898/2026.09.01.748611
  10. Transl Neurodegener. 2026 Oct 28. pii: 58. [Epub ahead of print]15(1):
      Neurodegenerative diseases such as Alzheimer's disease (AD), frontotemporal dementia (FTD), and Parkinson's disease (PD) are characterized by the accumulation of intrinsically disordered proteins (IDPs), including amyloid-β (Aβ), tau, and α-synuclein (αSyn). These proteins disrupt neuronal homeostasis through toxic aggregation, impaired proteostasis, and progressive neurodegeneration, in part via dysfunction of the autophagy-lysosomal pathway (ALP). A central feature of this impairment is defective vacuolar-type (H+)-ATPase (V-ATPase) function, leading to lysosomal deacidification and reduced degradative capacity. Pathological IDP species converge on V-ATPase through direct interactions with its subunits or by perturbing its assembly, while also exerting protein-specific effects, including lysosomal membrane destabilization, impaired hydrolase activity, and disrupted endolysosomal trafficking. These combined mechanisms create a reciprocal relationship between lysosomal dysfunction and IDP accumulation, in which impaired lysosomal degradation further promotes the persistence and aggregation of pathological IDP species. This review synthesizes current insights into the molecular interplay between IDPs and lysosomal acidification across AD, FTD, and PD, and highlights how these processes contribute to disease progression. We further discuss emerging therapeutic strategies aimed at restoring lysosomal function. These findings underscore lysosomal dysfunction as a common feature of IDP-driven neurodegeneration and a potential therapeutic target across these disorders.
    Keywords:  Autophagy; Intrinsically disordered proteins; Lysosomal acidification; Neuroinflammation and neurodegeneration; Protein degradation; Therapeutic strategies
    DOI:  https://doi.org/10.1186/s40035-026-00591-z
  11. Autophagy. 2026 Oct 29. 1-33
      Modification by ubiquitination governs the half-lives of thousands of proteins that are fated for elimination by either the proteasome or autophagy pathways, depending on the intricate architectures of ubiquitin modification. This system mediates quality control for individual proteins, protein complexes, and organelles, as well as myriad purely regulatory functions. Here we provide a comprehensive survey of the ubiquitin-proteasome system (UPS), the scope of which is at present poorly defined. The UPS, with the inclusion of pathways involving ubiquitin-like modifiers, comprises in our estimate over 1430 distinct components in humans, a vast set of activities whose collective impact on the biology of the cell is pervasive. The UPS is an integral component of the proteostasis network (PN), the remainder of which is surveyed in the accompanying reports. With the addition of molecular chaperones, proteins from autophagy-lysosome pathway, and related activities, the PN includes in total over 3150 components by our estimates. Comprehensive and systematic definition of these pathways should facilitate a range of ongoing investigations in the areas of genomics, proteomics, biochemistry, cell biology, and disease research.Abbreviations: APC, anaphase promoting complex; CDD, Conserved Domain Database; CRL, cullin RING ligase; DSB, double-strand break; DUB, deubiquitinating enzyme; ERAD, ER-associated degradation; PN, proteostasis network; RBR, RING-between-RING; RCR, RING-Cys-Relay; SPOC, Structure Prediction and Omics-informed Classifier; UB, ubiquitin; UBL, ubiquitin-like; UBLM, ubiquitin-like modifier; UEV, ubiquitin-conjugating enzyme variant; UPS, ubiquitin-proteasome system.
    Keywords:  Cullin; UFMylation; deubiquitination; sumoylation; ubiquitin ligase; ubiquitin-like modifier
    DOI:  https://doi.org/10.1080/15548627.2026.2741092
  12. Front Neurol. 2026 ;17 1891393
      The accumulation of α-synuclein (α-syn) in the form of Lewy bodies and Lewy neurites is a neuropathological hallmark of Parkinson's disease (PD) and is closely associated with disease progression. Targeting the autophagy pathway to enhance the clearance of α-syn aggregates therefore represents a promising therapeutic strategy. In the present study, we conducted high-throughput screening using rat embryonic primary neurons, followed by validation of the identified compounds in human induced pluripotent stem cell (iPSC)-derived neurons. We identified dibucaine, a local anesthetic, as a compound that induced autophagic flux in neuronal models. In human iPSC-derived dopaminergic neurons from a patient with PD carrying an SNCA duplication, dibucaine reduced cellular levels of Ser129-phosphorylated α-synuclein (pS129 α-syn). In SH-SY5Y cells, dibucaine increased 5'-AMP-activated protein kinase (AMPK) Thr172 phosphorylation. LY364947 partially attenuated dibucaine-induced LC3-II accumulation in the iPSC-derived neurons through an unidentified mechanism. Although the requirement for AMPK and the mechanism underlying the reduction in pS129 α-syn remain unresolved, our findings show that dibucaine induces autophagic flux and reduces pS129 α-syn levels in disease-relevant human neurons.
    Keywords:  Parkinson’s disease; alpha-synuclein; autophagy; dibucaine; neurodegenerative disease; protein aggregation
    DOI:  https://doi.org/10.3389/fneur.2026.1891393
  13. Am J Physiol Cell Physiol. 2026 Oct 16.
      Intracellular proteolytic mechanisms are important in clearing aberrant proteins causal for different pathologies including cardiovascular diseases, cancer, and neurological disorders. Chaperone-mediated autophagy (CMA) is a protein degradation pathway that employs chaperones to bind proteins bearing a unique KFERQ (Lys-Phe-Asp-Arg-Gln)-like motif and delivers them to lysosomes for degradation via a CMA-specific receptor, namely, Lysosome Associated Membrane Protein 2A (LAMP2A). Several assays are available to monitor CMA function. However, most of these methods are laborious, expensive and cannot be performed on frozen samples. We have developed a straightforward and inexpensive fluorogenic assay to assess CMA activity in both fresh and frozen samples. The CMA substrate, KFERQ-AMC (7-amino-4-methylcoumarin), was synthesized by Solid-Phase Peptide Synthesis. Mechanistically, AMC fluorescence remains quenched when the fluorophore is conjugated to KFERQ. Upon lysosomal hydrolysis of KFERQ-AMC, free AMC is released, and its fluorescence levels serve as an indicator for CMA activity. Lysate from fresh or frozen mouse tissue and cells when incubated with the KFERQ-AMC peptide displayed a time-dependent increase in CMA activity (0-15 hours for tissues and 0-6 hours for cells). KFERQ-AMC fluorescence was markedly reduced in cultured cells following transfection with Lamp2a siRNA, indicating suppression of CMA activity. In contrast, overexpression of Lamp2a via adenoviral delivery enhanced CMA and promoted KFERQ-AMC degradation. Notably, inhibition of proteasomal or macroautophagic pathways had no effect on KFERQ-AMC degradation, underscoring the assay's specificity for CMA. This novel fluorescence-based approach provides a valuable tool for elucidating the role of CMA across diverse experimental systems.
    Keywords:  Chaperone-Mediated Autophagy; E64D; Fluorescence; KFERQ-AMC; LAMP2A; Lysosome; Macroautophagy; Peptides; Proteasome
    DOI:  https://doi.org/10.1152/ajpcell.90174.2026
  14. J Cell Biol. 2026 Dec 07. pii: e202606052. [Epub ahead of print]225(12):
      Recent work from two independent studies has uncovered mitochondria as a previously unrecognized proton source driving lysosomal acidification. In this Viewpoint, we summarize these findings, examine the associated proteins and functional mechanisms, and discuss their relevance to disease.
    DOI:  https://doi.org/10.1083/jcb.202606052
  15. Nat Commun. 2026 Sep 29. pii: 11215. [Epub ahead of print]17(1):
      During mitotic growth, Saccharomyces cerevisiae cells age by dividing asymmetrically, producing young daughter cells while retaining age-associated damage in the mother cell, which will eventually become senescent. Gametogenesis naturally and fully resets precursor cell lifespan, even for replicatively aged cells. However, the mechanisms responsible for gametogenic rejuvenation have remained mysterious. This is partly due to the existing methods to quantify lifespan resetting in this context, which are limited to low-throughput and labor-intensive approaches. Here, we introduce a high-throughput assay that allows systematic characterization of factors required for gametogenic rejuvenation. With this approach, we show that we can sensitively measure a wide range of gamete replicative lifespans that are consistent with established mutants. Excitingly, we also discover that Atg39 and Atg40, receptors involved in selective autophagy of the ER, are molecular determinants of gametogenic rejuvenation. This technique will enable systematic identification of the molecular factors that drive gametogenic rejuvenation.
    DOI:  https://doi.org/10.1038/s41467-026-77993-0
  16. bioRxiv. 2026 Sep 02. pii: 2026.09.01.748694. [Epub ahead of print]
      In Caenorhabditis elegans, a brief, sublethal heat shock (HS) induces a hormetic response that increases resistance to subsequent stress and extends lifespan. These benefits require hlh-30, the ortholog of mammalian transcription factor EB (TFEB). Although HS induces robust HLH-30 nuclear translocation, how this response is regulated remains poorly understood. Nutrient- and energy-sensing pathways, including mTORC1 and AMPK, regulate HLH-30/TFEB subcellular localization under other physiological conditions, but whether they mediate its nuclear translocation during HS is unknown. Here, we show that, although HS inhibited mTORC1 and dephosphorylated its conserved HLH-30 S201 target site, HLH-30 S201 phosphorylation was dispensable for HS-induced HLH-30 nuclear localization and hormetic protection. Moreover, HS remained protective in hlh-30 mutants when mTORC1 activity was reduced, revealing an HLH-30-independent component of the hormetic response. HS also activated AMPK and aak-2 was required for hormetic protection but dispensable for HS-induced HLH-30 nuclear localization and autophagosome formation. Together, these findings demonstrate that although HS engages canonical mTORC1 and AMPK signaling, these pathways do not account for HS-induced HLH-30 nuclear localization and instead make distinct contributions to hormetic protection. Our findings reveal stress-specific regulation of HLH-30/TFEB and point to additional mechanisms that drive its activation during heat stress.
    DOI:  https://doi.org/10.64898/2026.09.01.748694
  17. Autophagy. 2026 Oct 28. 1-27
      The network of transcription factors (TFs) is an integral component of executing macroautophagy/autophagy-lysosome gene expression to maintain cellular homeostasis. Across metazoans, conserved TFs, particularly the helix-loop-helix factor TFEB, convert upstream signals into specific genetic programs through mechanisms ranging from DNA recognition and chromatin remodeling to biomolecular condensates. The dysregulation of TF-governed gene programming disrupts the progression of metabolic disease and cancer, highlighting that dissection of transcriptional regulation makes it a promising therapeutic target. Consequently, instead of indirectly modulating the pathways in which they are involved, targeting these essential TFs directly is becoming a new trend for pharmaceutical development. In this review, we systematically elucidate current mechanisms of the TF-driven autophagic transcriptome, and summarize current small molecules targeting these TFs in various disease.Abbreviations: AD: Alzheimer disease; AFF4: ALF transcription elongation factor 4; AKT: AKT serine/threonine kinase; AMPK: AMP-activated protein kinase; AR: androgen receptor; ATF4: activating transcription factor 4; ATG: autophagy related; BECN1: beclin 1; BNIP3: BCL2 interacting protein 3; BRD4: bromodomain containing 4; CRC: colorectal cancer; CREBBP/CBP: CREB binding lysine acetyltransferase; CTNNB1/β-catenin: catenin beta 1; DBD: DNA-binding domain; DDIT3: DNA damage inducible transcript 3; DRAM1: DNA damage regulated autophagy modulator 1; E2F1: E2F transcription factor 1; EHMT2/G9a: euchromatic histone lysine methyltransferase 2; EO: eltrombopag; EP300/p300: EP300 lysine acetyltransferase; ERBB2: erb-b2 receptor tyrosine kinase 2; FOXO3: forkhead box O3; GSH: glutathione; GSK3B/GSK3β: glycogen synthase kinase 3 beta; HD: Huntington disease; KAT2B/GCN5: lysine acetyltransferase 2B; HMGB1: high mobility group box 1; KDACs: lysine deacetylases; KEAP1: kelch like ECH associated protein 1; KLF4: KLF transcription factor 4; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MAPK: mitogen-activated protein kinase; MITF: melanocyte inducing transcription factor; MTORC1: mechanistic target of rapamycin kinase complex 1; MiT/TFE: microphthalmia-transcription factor E; MYC: proto-oncogene, bHLH transcription factor; NDs: neurodegenerative disorders; NFE2L2/NRF2: NFE2 like bZIP transcription factor 2; P-TEFb: positive transcription elongation factor b; PARP1: poly(ADP-ribose) polymerase 1; PD: Parkinson disease; PIC: pre-initiation complex; PIK3C3/VPS34: phosphatidylinositol 3-kinase catalytic subunit type 3; PTMs: post-translational modifications; POLR2: RNA polymerase II; SIRT1: sirtuin 1; SNAI2: snail family transcriptional repressor 2; STAT3: signal transducer and activator of transcription 3; TFE3: transcription factor binding to IGHM enhancer 3; TFEB: transcription factor EB; TFs: transcription factors; TNKS: tankyrase; TP53: tumor protein p53; ULK1: unc-51 like autophagy activating kinase 1; YWHA/14-3-3: tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein; YY1: YY1 transcription factor; ZKSCAN3: zinc finger with KRAB and SCAN domains 3.
    Keywords:  Autophagy; POLR2 dynamics; PTMs; epigenetic regulation; pharmacological strategies; transcription factors
    DOI:  https://doi.org/10.1080/15548627.2026.2753996
  18. Cell Rep. 2026 Oct 26. pii: S2211-1247(26)01262-3. [Epub ahead of print]45(11): 118183
      Increasing evidence supports a pathogenic role for impaired energy metabolism in organ damage. Genetic diseases provide opportunities to investigate these mechanisms, as exemplified by Fabry disease (FD), caused by an α-galactosidase A (GLA) deficiency and globotriaosylceramide (Gb3) accumulation, with cardiomyopathy as the leading cause of death. Beyond Gb3 storage, impaired energy metabolism may contribute to cardiomyopathy. Here, we demonstrate mitochondrial dysfunction in FD heart and its therapeutic targeting. Using a humanized FD mouse model (R301Q-Tg/GLA knockout), embryonic fibroblasts, and neonatal and adult cardiomyocytes, we found impaired mitophagy and mitochondrial respiration, increased reactive oxygen species, and a vicious cycle aggravating lysosomal dysfunction. These defects progressed with age, causing accumulation of dysfunctional mitochondria, energetic failure, apoptosis, cardiac hypertrophy, and diastolic dysfunction. L-arginine, promoting NO/PGC-1α-dependent mitochondrial rescue, prevented cardiac abnormalities. Our findings identify mitochondrial dysfunction as a key driver of FD cardiomyopathy and reveal the lysosome-mitochondria axis as a targetable pathway in FD and beyond.
    Keywords:  CP: Cell biology; CP: Metabolism; Fabry disease; L-arginine; mitochondria; mitophagy
    DOI:  https://doi.org/10.1016/j.celrep.2026.118183
  19. J Neurochem. 2026 Oct;pii: e70561. [Epub ahead of print]170(10):
      PINK1 and Parkin regulate mitochondrial quality control in both neuronal and immune-cell populations, but their roles during autoimmune neuroinflammation in aging remain incompletely understood. We investigated the association of PINK1 or Parkin deficiency with clinical disease, peripheral immune responses, CNS inflammation, and neuronal mitochondrial morphology during experimental autoimmune encephalomyelitis (EAE). EAE was induced in aged PINK1-/- and PARK2-/- mice and age-matched controls. Clinical disease was assessed longitudinally, while independent cohorts were analyzed at peak disease using flow cytometry, spinal cord histology, transmission electron microscopy, and Western blotting of mitochondrial fractions. PINK1-/- and PARK2-/- showed greater cumulative disease burden and incomplete clinical recovery, most prominently in PARK2-/- mice. At peak disease, knockout mice exhibited increased dendritic cells, monocytes, and CD8+ T cells, while aged knockouts showed more IFN-γ-producing CD4+ and CD8+ T cells following ex vivo stimulation. Increased spinal cord inflammation was not accompanied by genotype-dependent differences in myelin staining. Ultrastructural analysis revealed more numerous, smaller mitochondria in substantia nigra pars compacta and motor cortex neurons, accompanied by selective alterations in OPA1 and DRP1, but not MFN2. These findings demonstrate that PINK1 or Parkin deficiency is associated with enhanced inflammation, greater EAE disease burden, and altered neuronal mitochondrial morphology in aging. These results support an association between immune dysregulation and altered mitochondrial homeostasis without establishing impaired mitophagy or a direct causal relationship.
    Keywords:  EAE; PARKIN; PINK1; aging; mitochondrial fragmentation; mitophagy; neuroinflammation; substantia nigra
    DOI:  https://doi.org/10.1111/jnc.70561
  20. medRxiv. 2026 Sep 01. pii: 2026.08.27.26360298. [Epub ahead of print]
      Pathogenic variants in RUBCN , encoding the Run domain Beclin-1 interacting and cysteine-rich domain-containing protein (Rubicon) have been implicated in autosomal recessive spinocerebellar ataxia 15 (SCAR15). However, the molecular mechanisms underlying disease pathogenesis remain poorly understood. Here, we report 18 individuals from 15 unrelated families harbouring biallelic RUBCN variants, who present with an aggressive neurodevelopmental disorder variably characterized by seizures, developmental delay, intellectual disability and movement abnormalities that cause regression, progressive brain atrophy and neurodegenerative features. Through functional characterization, we demonstrate that a subset of disease-associated putative truncating variants disrupt autophagy regulation. In Caenorhabditis elegans models, loss-of-function RUBCN variants result in an increased autophagic flux and impaired neuronal function, recapitulating key features in humans. Correspondingly, cellular assays reveal that nonsense and frameshift RUBCN variants lead to defective autophagy inhibition, underscoring a crucial role for RUBCN as a key negative autophagy regulator. Molecular dynamics simulations rank the eleven missense variants by structural effect, with p.Arg813Trp alone altering the target protein at both the local and the regional level and lying within the RAB7A-binding module that the truncating alleles remove altogether. Our findings establish and expand the RUBCN -related disorders as a clinically and molecularly distinct subset of autophagy-related diseases. By delineating both the genetic landscape and cellular consequences of Rubicon dysfunction, this study enhances our understanding of autophagy-related neurodevelopmental disorders and provides a foundation for future therapeutic investigations.
    DOI:  https://doi.org/10.64898/2026.08.27.26360298
  21. Front Immunol. 2026 ;17 1942769
      Glioma remains largely refractory to immune-checkpoint blockade, in part because tumor-intrinsic mechanisms sustain programmed death-ligand 1 (PD-L1) and reinforce an immunosuppressive microenvironment. Tripartite motif-containing 14 (TRIM14) is an immune associated protein. However, the role of TRIM14 in PD-L1 homeostasis in glioma is incompletely defined. Here we reported that TRIM14 was increased in malignancies and was particularly associated with overall survival in glioma. Single-nucleus analysis showed that TRIM14-positive nuclei were predominantly malignant, indicating association between TRIM14 and glioma progression. We also found TRIM14 upregulated PD-L1 protein levels without materially changing CD274 mRNA in glioma cells. Additionally, knockout of TRIM14 reduced tumor growth in vivo. Mechanistically, TRIM14 recruits deubiquitinase BRCC3 to reduce K63-linked ubiquitination of PD-L1 in glioma cells, thereby inhibiting p62-mediated autophagic degradation of PD-L1. This pathway prompts that TRIM14 or BRCC3 maybe candidate targets for therapeutic intervention in glioma.
    Keywords:  PD-L1; TRIM14; glioma; selective autophagy; ubiquitination
    DOI:  https://doi.org/10.3389/fimmu.2026.1942769
  22. bioRxiv. 2026 Sep 01. pii: 2026.08.27.747662. [Epub ahead of print]
      Tauopathies are characterized by the accumulation and spread of pathogenic tau aggregates throughout the brain, a process that is increasingly recognized to involve not only neurons but also microglia. However, whether pathogenic MAPT directly alters microglial degradative capacity remains poorly understood. Here, using isogenic human induced pluripotent stem cell-derived microglia carrying the pathogenic MAPT IVS10+16 mutation, we identify tau as a regulator of microglial lysosomal function. MAPT IVS10+16 microglia exhibited coordinated suppression of lysosomal and autophagic pathways, reduced lysosomal protease abundance and activity, and impaired autophagosome-lysosome fusion. Mutant microglia also showed reduced uptake of extracellular tau aggregates, reduced tau accumulation in acidic compartments, and a blunted lysosomal response to proteopathic stress. Conversely, genetic loss of MAPT increased lysosomal degradative capacity and accumulation of extracellular tau aggregates within acidic compartments, supporting a cell-intrinsic role for endogenous tau in regulating microglial degradative function. Pharmacologic enhancement of the autophagy lysosome pathway in MAPT IVS10+16 microglia increased proteolytic activity and improved tau handling. Together, these findings reveal a reciprocal relationship between tau and microglial lysosome function and identify degradative capacity as a modifiable component of the microglial response to tau pathology.
    DOI:  https://doi.org/10.64898/2026.08.27.747662
  23. J Mol Cell Biol. 2026 Oct 30. pii: mjag046. [Epub ahead of print]
      Hair follicle (HF) development and regeneration rely on the precise differentiation of hair follicle stem cells (HFSCs), a process governed by epigenetic regulation. While nutrient-sensing mTOR signaling is known to be pivotal, the upstream epigenetic triggers and the downstream events orchestrating this pathway remain poorly defined. The histone H3K9me2 demethylase KDM3B has recently emerged as a key player in stem cell fate decisions. By integrating recent high-throughput sequencing data and employing a conditional knockout mouse model, we demonstrated that KDM3B was essential for HFSC differentiation, as its loss led to severe defects in postnatal HF development and HFSC differentiation. Mechanistically, we identified the mTOR signaling pathway and its downstream protein translation machinery as the primary effectors of KDM3B. KDM3B activated mTOR complex 1 (mTORC1) signaling, which subsequently upregulated the TOP mRNA-binding protein LARP1 to drive ribosome biogenesis and global protein synthesis. Our work delineated a complete 'KDM3B-mTORC1-LARP1-ribosome' axis that functionally integrates epigenetic control with translational regulation to direct HFSC differentiation. These findings not only establish KDM3B as a novel key regulator in skin epithelia but also provide the first comprehensive mechanistic link from an epigenetic modifier through the mTOR pathway to the ribosomal translation program within the HF model.
    Keywords:  AKT–mTOR pathway; KDM3B; hair follicle differentiation; hair follicle stem cells; ribosome
    DOI:  https://doi.org/10.1093/jmcb/mjag046
  24. Sci Adv. 2026 Oct 30. 12(44): eaeg1787
      Chaperone-mediated autophagy (CMA), regulated by its lysosomal receptor LAMP2A, is a key pathway for αSynuclein (αSyn) clearance and a direct target of αSyn-related neurotoxicity. Rodent studies show that LAMP2A enhancement reverses neurodegeneration, whereas its deficiency accelerates pathology. To test translational relevance, we examined whether increasing LAMP2A expression in nonhuman primates could mitigate α-synucleinopathy induced by injections of Parkinson's disease patient-derived Lewy body (LB) extract. Increasing LAMP2A expression protected nigral dopaminergic neurons from LB-induced αSyn neurodegeneration, delayed the formation and release of pathology-related αSyn species, and evoked a beneficial effect on motor behavior and on cognitive functions of the primate model. Our findings provide preliminary preclinical evidence supporting CMA enhancement as a therapeutic strategy for αSynucleinopathies.
    DOI:  https://doi.org/10.1126/sciadv.aeg1787
  25. Am J Physiol Cell Physiol. 2026 Oct 19.
      Transmembrane protein 175 (TMEM175) is a lysosomal cation channel that has emerged as a promising drug target for Parkinson's disease (PD). Genetic and functional studies linking TMEM175 loss-of-function variants to increased PD risk, lysosomal dysfunction, and α-synuclein accumulation have generated considerable interest in developing pharmacological approaches to enhance channel activity. As a lysosomal cation channel with reported K+ and H+ permeability, TMEM175 regulates lysosomal membrane potential, pH stability, autophagic flux, and degradative capacity, placing it at a critical control point for cellular proteostasis. Recent advances in high-throughput screening, automated and lysosomal patch clamp electrophysiology, cryoelectron microscopy, and structure-guided medicinal chemistry have transformed TMEM175 from a relatively obscure lysosomal ion channel into a tractable drug target. These approaches have enabled the discovery of multiple classes of TMEM175 modulators while providing new insights into channel gating and mechanisms of activation. In this review, we summarize current progress in TMEM175 pharmacology, including advances in functional assay development and the emerging landscape of tool compounds used to study channel function. We discuss TMEM175 physiology and structure-function relationships, the growing evidence supporting therapeutic intervention, and recent discoveries revealing multiple mechanisms of channel activation. Finally, we highlight key challenges that remain for the field, including the development of potent and selective modulators, opportunities afforded by synergistic channel activation, and the potential application of TMEM175-directed therapeutics beyond Parkinson's disease in a broader range of neurodegenerative and lysosome-associated disorders.
    Keywords:  Parkinson’s disease; TMEM175; ion channel pharmacology; lysosome; α-synuclein clearance
    DOI:  https://doi.org/10.1152/ajpcell.90012.2026
  26. Autophagy. 2026 Oct 27. 1-15
      The condition of having a healthy, functional proteome is known as protein homeostasis, or proteostasis. Maintaining proteostasis is the province of the proteostasis network, which consists of the cellular components that regulate protein synthesis, folding, localization, and degradation. The proteostasis network is a fundamental functional unit in biology with relevance to many diseases. Despite its importance, the human proteostasis network has until now lacked a precise definition, limiting our ability to interrogate proteostasis, integrate multiomic datasets, compare results across studies, or model proteostasis dysfunction in disease. To address this limitation, we have operationally defined the human proteostasis network by providing a comprehensive, annotated, and manually curated list of its components classified into nine Branches based on their function and localization - cytonuclear proteostasis, ER proteostasis, mitochondrial proteostasis, nuclear proteostasis, proteostasis network regulation, translation, extracellular proteostasis, the autophagy-lysosome pathway, and the ubiquitin-proteasome system - which we present in a series of three manuscripts of which this is the first. Overall, the proteostasis network annotation encompasses 3,151 components described by 4,043 annotations. Here, we present the 1,190 components that make up the first seven of these Branches, which comprise the compartment-based proteostasis network (cytonuclear, ER, mitochondrial, nuclear, and extracellular proteostasis), proteostasis network regulation, and translation. These Branches include chaperones, folding enzymes, systems for trafficking proteins, organelle-specific degradation systems, and the cell's translation machinery. This work provides a framework that will facilitate insights into how proteostasis is preserved in health, lost in aging and disease, and how it could be restored through pharmacological intervention.
    Keywords:  Annotation; cellular stress responses; chaperones; protein folding; protein synthesis; protein transport
    DOI:  https://doi.org/10.1080/15548627.2026.2741033
  27. Exp Neurol. 2026 Oct 30. pii: S0014-4886(26)00469-3. [Epub ahead of print] 116101
      Cerebral ischemia-reperfusion (I/R) injury is a major contributor to ischemic cerebral damage and poor functional outcomes following ischemic stroke, and effective neuroprotective strategies remain limited. Remote ischemic preconditioning (RIPC) has emerged as a promising, noninvasive approach; however, its underlying mechanisms are incompletely understood. Here, we investigated whether lactate serves as a key metabolic mediator linking RIPC to neuroprotection through regulation of autophagy. Using an oxygen-glucose deprivation/reoxygenation (OGD/R) model in PC12 cells and a middle cerebral artery occlusion (MCAO) model in rats, we demonstrate that I/R impairs autophagic flux, as evidenced by p62 accumulation and reduced LC3-II and Beclin-1 expression, leading to increased cellular apoptosis and injury. Lactate supplementation restored autophagic flux, enhanced cell viability, and suppressed apoptosis under OGD/R conditions. Mechanistically, lactate activated the AMPK/ULK1 signaling pathway, whereas pharmacological inhibition of AMPK or ULK1 attenuated lactate-induced autophagy and cytoprotection. In vivo, RIPC elevated plasma and cerebral lactate levels, activated AMPK/ULK1 signaling, promoted autophagy, reduced infarct volume, and improved acute neurological outcomes. Notably, blockade of lactate transport or inhibition of AMPK/ULK1 signaling attenuated these protective effects. Collectively, our findings suggest that lactate serves as an important mediator of RIPC-induced neuroprotection and reveal a novel lactate-AMPK/ULK1-autophagy axis that mitigates cerebral I/R injury. These results provide mechanistic insight into RIPC and suggest potential therapeutic targets for ischemic stroke.
    Keywords:  AMPK/ULK1 signaling; Autophagy; Cerebral ischemia-reperfusion injury; Lactate; Remote ischemic preconditioning
    DOI:  https://doi.org/10.1016/j.expneurol.2026.116101
  28. J Biochem. 2026 Oct 31. pii: mvag081. [Epub ahead of print]
      SKN-1, a Cap'n'Collar transcription factor in Caenorhabditis elegans, is a well-established regulator of oxidative stress responses and xenobiotic detoxification. Over the past two decades, the late Dr. T. Keith Blackwell (1957-2025) and colleagues made seminal contributions to defining its biological functions and regulatory mechanisms. Owing to its robust conservation with mammalian Nrf family proteins, SKN-1 research has yielded fundamental insights into how nutrient and stress signals modulate metabolism, proteostasis, and aging. Recently, the discovery that distinct SKN-1 isoforms execute unique physiological roles has further refined this field. In this review, we summarize how SKN-1 regulates longevity, particularly through the mTOR nutrient-sensing pathway, discuss recent advances in isoform-specific regulation, and highlight critical questions for future research.
    Keywords:   C. elegans ; Lifespan; SKN-1; mTOR
    DOI:  https://doi.org/10.1093/jb/mvag081