Journal of Biological Chemistry最新文献

{"title":"First-in-class inhibitors of Nsp15 endoribonuclease of SARS-CoV-2: modeling, synthesis, and enzymatic assay of thiazolidinedione and rhodanine analogs.","authors":"Nimer Mehyar,Nosaibah Samman,Shatha Al Gheribi,Abdullah Mashhour,Pearl Chan,Rabih O Al-Kaysi,Stanley Perlman,Mohamed Boudjelal,Imadul Islam","doi":"10.1016/j.jbc.2025.110409","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110409","url":null,"abstract":"During infection, the coronavirus Nsp15, a uridine-specific endoribonuclease, suppresses the host cell's antiviral response. Recently, researchers have paid more attention to this relatively underexplored yet potentially viable drug target. In this study, we employed fluorescence resonance energy transfer-based screening assays to identify potent Nsp15 inhibitors. Subsequently, we used active-site in silico docking methods to design new molecules with enhanced inhibitory properties. Solution assays were used to measure the potency and determine the mechanism of these inhibitors. We identified a novel class of thiazolidinedione and rhodanine analogs that inhibit SARS-CoV-2 Nsp15. Docking these compounds into the uridine-binding site shows that most analogs form two hydrogen bonds with Ser294. The most potent inhibitors are compounds KCO237 and KCO251 (half-maximal inhibitory concentration: 0.304 μM, 0.931 μM respectively). The inhibition kinetics of KCO237 and KCO251 best align with a reversible mixed inhibition model. Mutating Ser294 did not completely abolish Nsp15 activity or the inhibitory effect of KCO237 or KCO251. These findings suggest that thiazolidinedione and rhodanine analogs likely inhibit Nsp15 by binding to the uridine active site while also implicating a possible secondary allosteric binding site. The ability of these compounds to inhibit VERO 6 cell infection with SARS-CoV-2 at subtoxic levels highlights their potential for development as novel antiviral treatments for SARS-CoV-2 and other coronavirus-related diseases.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":"27 1","pages":"110409"},"PeriodicalIF":4.8,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144488033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence against efficient spontaneous disassembly of prions into small oligomers","authors":"Daniel Shoup, Andrew G. Hughson, Brent Race, Parvez Alam, Daniel Dulebohn, Suzette A. Priola, Byron Caughey","doi":"10.1016/j.jbc.2025.110411","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110411","url":null,"abstract":"Infectious prion assemblies must fragment to replicate, spread, and trigger disease. However, the extent to which various types of amyloid fibrils fragment on their own versus being driven by other cellular processes is unclear. In the case of highly infectious, tissue-derived prion (PrP<ce:sup loc=\"post\">Sc</ce:sup>) preparations, over 40 years of previous studies have yielded starkly contradictory indications on this question. Many have reported high stability of PrP<ce:sup loc=\"post\">Sc</ce:sup> multimers in even strong detergents. However, others using non-disinfecting detergents and size exclusion chromatography combined with light scattering measurements, have described complete spontaneous disassembly into dimeric-tetrameric units. In attempting to replicate the latter experiments, we determined that PrP<ce:sup loc=\"post\">Sc</ce:sup> size exclusion elution behavior was dominated by binding to the column matrix, not particle size. The light scattering behavior of fractions containing PrP<ce:sup loc=\"post\">Sc</ce:sup> was dominated by the co-elution of detergent micelles similar in size to hypothetical PrP<ce:sup loc=\"post\">Sc</ce:sup> dimers-trimers. Furthermore, sedimentation velocity centrifugation and electron microscopy indicated that most detergent-treated PrP<ce:sup loc=\"post\">Sc</ce:sup> particles remained larger than 70-mers. When added to live cells that lacked PrP<ce:sup loc=\"post\">C</ce:sup> and were therefore incapable of new PrP<ce:sup loc=\"post\">Sc</ce:sup> assembly, most PrP<ce:sup loc=\"post\">Sc</ce:sup> remained in the form of large multimers for ≥24 h, confirming substantial stability in a cellular model. Thus, we found no evidence that the much larger assemblies that predominate in brain homogenates or purified PrP<ce:sup loc=\"post\">Sc</ce:sup> preparations fragment spontaneously into small oligomers. Moreover, our identification of prion-associated size exclusion chromatography artifacts reconciles previously disparate reports about prion disassembly.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":"48 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144341316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Maintenance of proper phosphatidylinositol-4-phosphate level by Stt4 and Sac1 contributes to vesicular transport to and from the plasma membrane","authors":"Tomoki Sano, Makoto Nagano, Hiroki Shimamura, Wataru Yamamoto, Tomoyuki Tamada, Junko Y. Toshima, Jiro Toshima","doi":"10.1016/j.jbc.2025.110410","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110410","url":null,"abstract":"Growing evidence suggests that counter-transport of phosphatidylinositol-4-phosphate (PtdIns(4)P) and phosphatidylserine (PS) at endoplasmic reticulum (ER)-plasma membrane (PM) contact sites is required for intracellular vesicle transport. PtdIns(4)P is metabolized by Stt4 PI 4-kinase residing at the PM and by Sac1 PtdIns(4)P phosphatase at the ER, and ER-PM contact sites are believed to be important for its efficient turnover. Recently, Stt4 has been shown to extensively localize to ER-PM contact sites. However, the precise location of Stt4 and the mechanism of localization to these sites have not been clarified. Additionally, although several studies have suggested a requirement for PS/PtdIns(4)P and sterol/PtdIns(4)P exchange at ER-PM contact sites in endocytosis, it is still unclear whether contact between the ER and PM, turnover of PtdIns(4)P or PS, or maintenance of PtdIns(4)P or PS levels is more important. Here we found that Stt4 localizes to the cER regions where Scs2 and Ist2 are localized abundantly, and that localization of Stt4 is maintained in the Δtether mutant, which has a reduced number of ER-PM contact sites. We also demonstrated that the Δtether and <ce:italic>sac</ce:italic>1Δ mutants showed defects at different stages of endocytosis, and that inactivation mutation of Stt4 restored the endocytosis defect only in the Δtether mutant. Furthermore, these mutants exhibited defective transport in the secretory and recycling pathways, and inactivation of Stt4 restored the secretory pathway in the Δtether mutant, but not the recycling pathway in either mutant. These results suggest that endocytosis, secretion, and recycling pathways are regulated directly or indirectly by different PtdIns(4)P-mediated mechanisms.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":"245 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144341340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the substrate recognition and catalytic mechanism of methyl fucosidases from glycoside hydrolase family 139","authors":"Zak McIver, Alicia Moraleda-Montoya, Zongjia Chen, Ruwan Epa, David Starns, Matthew Davy, Mikel García-Alija, Arnaud Basle, Mario Schubert, Didier Ndeh, Beatriz Trastoy, Spencer J. Williams, Marcelo E. Guerin, Alan Cartmell","doi":"10.1016/j.jbc.2025.110407","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110407","url":null,"abstract":"Rhamnogalacturonan II is one of the most complex plant cell wall carbohydrates and is composed of 13 different sugars and 21 different glycosidic linkages. It is abundant in fruit and indulgence foods, such as chocolate and wine, making it common in the human diet. The human colonic commensal <ce:italic>Bacteroides thetaiotaomicron</ce:italic> expresses a consortium of 22 enzymes to metabolise rhamnogalacturonan II, some of which exclusively target sugars unique to rhamnogalacturonan II. Several of these enzyme families remain poorly described, and, consequently, our knowledge of rhamnogalacturonan II metabolism is limited. Chief among the poorly understood activities is glycoside hydrolase (GH) family 139, with targets α1,2-2<ce:italic>O</ce:italic>-methyl L-fucoside linkages, a sugar residue a sugar not found in any other plant cell wall complex glycans. Although the founding enzyme BT0984 was placed in the RG-II degradative pathway, no GH139 structure or catalytic blueprint had been available. We report the crystal structures of BT0984 and a second homologue, and reveal that the family operates with inverting stereochemistry. Using this data we undertook a mutagenic strategy, backed by molecular dynamics, to identify the important substrate binding and catalytic residues, mapping these residues throughout the GH139 family revealing the importance of the <ce:italic>O</ce:italic>2 methyl interaction of the substrate. We propose a catalytic mechanism that uses a non-canonical Asn as a catalytic base and shares similarity with L-fucosidases/L-galactosidases of family GH95.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":"18 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144341341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PLK1-mediated PDHA1 phosphorylation drives mitochondrial dysfunction, mitophagy, and cancer progression in Cr(VI)-associated lung cancer","authors":"Qiongsi Zhang, Jia Peng, Zhiguo Li, Xiongjian Rao, Derek B. Allison, Qi Qiao, Zhuangzhuang Zhang, Yifan Kong, Yanquan Zhang, Ruixin Wang, Jinghui Liu, Xinyi Wang, Chaohao Li, Fengyi Mao, Qing Shao, Tianyan Gao, Xiaoqi Liu","doi":"10.1016/j.jbc.2025.110406","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110406","url":null,"abstract":"Hexavalent chromium (Cr(VI)) is a class I environmental carcinogen that induces lung epithelial cell transformation and promotes lung cancer progression by altering cell cycle regulation and cellular energy metabolism. In this study, we investigated the role of polo-like kinase 1 (PLK1) in Cr(VI)-transformed (CrT) bronchial epithelial cells (BEAS-2B) and found that PLK1 expression was significantly upregulated in these cells, leading to impaired mitochondrial function and enhanced mitophagy, which in turn stimulated cell proliferation both in vitro and in vivo. Mechanistically, we demonstrated that PLK1 directly phosphorylates the pyruvate dehydrogenase E1 subunit alpha 1 (PDHA1) at Thr57, leading to its destabilization and disruption of pyruvate dehydrogenase complex (PDHc) integrity. This modification inhibits oxidative phosphorylation (OXPHOS) and induces mitochondrial dysfunction. Furthermore, mitochondrial dysfunction triggers mitophagy and accelerates PDHA1 degradation, establishing a positive feedback loop that amplifies mitochondrial impairment and mitophagy, ultimately promoting cancer cell proliferation. These findings underscore the pivotal role of PLK1 in Cr(VI)-associated cancer progression and offer new insights into potential therapeutic targets to inhibit Cr(VI)-induced tumorigenesis","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":"25 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144341318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Functional Genomics and Structural Insights into Maize Aldo-Keto Reductase-4 Family: Stress Metabolism and Substrate Specificity in Embryos","authors":"Sylvia Morais de Sousa, Priscila Oliveira de Giuseppe, Mario Tyago Murakami, Jiahn-Chou Guan, Jonathan W. Saunders, Eduardo Kiyota, Marcelo Leite Santos, Eric A. Schmelz, Jose Andres Yunes, Karen E. Koch","doi":"10.1016/j.jbc.2025.110404","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110404","url":null,"abstract":"Aldo-keto reductases (AKRs) are ubiquitous in nature and are able to reduce a wide range of substrates, from simple sugars to potentially toxic aldehydes. In plants, AKRs are involved in key metabolic processes including reactive aldehyde detoxification. This study aimed to i) delineate a maize gene family encoding Aldo Keto Reductase-4s (AKR4s) ii) help bridge sequence-to-function gaps among them, and iii) focus on a family member implicated in embryo specific stress metabolism. We employed a genome-wide analysis approach to identify maize genes encoding AKR4s, defining and annotating a 15-member gene family that clustered into three subgroups. Expression profiling, validated through wet lab experiments, revealed distinct functional roles: i) AKR4C Zm-1 functions in aldehyde detoxification during stress, ii) AKR4C Zm-2 includes stress-responsive AKRs with diverse substrate affinities, and iii) AKR4A/B Zm-3 contributes to specialized metabolites like phytosiderophores for iron transport. To investigate the impact of sequence variation on function, we characterized ZmAKR4C13, a representative of AKR4C Zm-1. Its mRNA and protein were predominantly localized in embryos, suggesting a specialized role. Recombinant ZmAKR4C13 efficiently reduced methylglyoxal and small aldehydes but showed poor activity toward aldoses larger than four carbons. Crystallographic analysis identified a size constraint at the active site, attributed to the bulkier LEU residue at position 294. Collectively, our results emphasize how subtle modifications in active-site architecture influence AKR substrate specificity. They also demonstrate a potential role of maize ZmAKR4C13 in detoxifying methylglyoxal and other small metabolites that could contribute to stress signaling in embryos.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":"15 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144341320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"HSD3B1 Upregulation via LRH1 Sustains Estrogen Receptor Signaling and Promotes Endocrine Resistance in Breast Cancer","authors":"Xiuxiu Li, Yoon-Mi Chung, Monaben Patel, Nima Sharifi","doi":"10.1016/j.jbc.2025.110405","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110405","url":null,"abstract":"Endocrine resistance is a major challenge in the treatment of estrogen receptor-positive (ER<ce:sup loc=\"post\">+</ce:sup>) breast cancer, often leading to disease recurrence and metastasis. 3β-Hydroxysteroid dehydrogenase 1 (3βHSD1, encoded by <ce:italic>HSD3B1</ce:italic>) catalyzes the rate-limiting conversion of dehydroepiandrosterone (DHEA) to androstenedione (AD), the major substrate for aromatase and a key precursor for estrogen biosynthesis. However, the regulation of <ce:italic>HSD3B1</ce:italic> in endocrine-resistant breast cancer remains unclear. We show that long-term estrogen deprivation (LTED) or tamoxifen treatment induces <ce:italic>HSD3B1</ce:italic> expression and enzymatic activity, sustaining DHEA metabolism and ER signaling in resistant ER<ce:sup loc=\"post\">+</ce:sup> breast cancer cells. T47D-LTED and T47D-4OHT cells exhibited increased <ce:italic>HSD3B1</ce:italic> expression and enhanced DHEA metabolism. <ce:italic>HSD3B1</ce:italic> deficiency impaired DHEA-driven survival, confirming its role in endocrine resistance. Mechanistically, we identify liver receptor homolog-1 (LRH1/NR5A2) as a key transcriptional regulator of <ce:italic>HSD3B1</ce:italic>. LRH1 inhibition suppressed <ce:italic>HSD3B1</ce:italic> expression, DHEA metabolism, and ER target gene activation, demonstrating its role in sustaining estrogen synthesis and tumor adaptation. Our findings establish <ce:italic>HSD3B1</ce:italic> as a critical mediator of endocrine resistance and identify LRH1 as an upstream regulator. Targeting <ce:italic>HSD3B1</ce:italic> or LRH1 may offer a new therapeutic strategy to restore endocrine sensitivity in ER<ce:sup loc=\"post\">+</ce:sup> breast cancer.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":"7 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144341319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A tubulin-binding protein that preferentially binds to GDP-tubulin and promotes GTP exchange.","authors":"Wesley J Yon, Taekjip Ha, Yixian Zheng, Ross T A Pedersen","doi":"10.1016/j.jbc.2025.110401","DOIUrl":"10.1016/j.jbc.2025.110401","url":null,"abstract":"<p><p>α- and β-tubulin are GTPases that form heterodimers and assemble into microtubules. Like other GTPases, the tubulin heterodimer's nucleotide-bound state regulates its activity. In the dimer, α-tubulin is constitutively bound to GTP, while β-tubulin can bind to either GDP (GDP-tubulin) or GTP (GTP-tubulin). Following assembly into microtubules, GTP-tubulin hydrolyzes GTP to GDP, triggering microtubule disassembly. This generates free GDP-tubulin which must exchange GDP for GTP to undergo assembly again. Tubulin dimers undergo rapid nucleotide exchange in vitro, leading to a commonly accepted belief that a tubulin guanine nucleotide exchange factor (GEF) may be unnecessary for microtubule assembly in cells. Here, we use quantitative binding assays to show that BuGZ, a spindle assembly factor, binds tightly to GDP-tubulin, less tightly to GTP-tubulin, and weakly to microtubules. We further show that BuGZ promotes the incorporation of GTP into tubulin using a nucleotide exchange assay. The discovery of a tubulin GEF suggests a mechanism that may aid rapid microtubule assembly dynamics in cells.</p>","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"110401"},"PeriodicalIF":4.0,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144340143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CryoEM Structure of Rv2531c Reveals Cofactor-Induced Tetramer-Dimer Transition in a Tuberculin Amino Acid Decarboxylase.","authors":"Jyoti Gupta,Tina Izard","doi":"10.1016/j.jbc.2025.110394","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110394","url":null,"abstract":"The survival of Mycobacterium tuberculosis relies on its ability to adapt to dynamic and hostile host environments. Amino acid decarboxylases play a crucial role in these adaptations, but their structural and mechanistic properties are not fully understood. Bioinformatic analyses revealed that these enzymes exist in three distinct forms based on their domain organization. We used cryogenic electron microscopy (cryoEM) at 2.86 Å resolution to show that Rv2531c exhibits unexpected oligomeric and conformational flexibility. The enzyme forms a tetramer with distinct open and closed conformations in its apo state, suggesting dynamic inter-subunit interactions. Upon binding pyridoxal 5'-phosphate (PLP), the enzyme undergoes a dramatic structural rearrangement, transitioning into a dimer. These findings reveal a novel mechanism of oligomeric plasticity. We also uncover an amino-terminal domain that might play a role in this process. Our results provide critical insights into the structural adaptations that support bacterial persistence under intracellular stress. By elucidating the apo and PLP-bound states of Rv2531c, we contribute to a deeper understanding of how M. tuberculosis navigates its challenging intracellular environment. These insights into the unique structural features of Rv2531c offer a foundation for targeting metabolic resilience in tuberculosis and open avenues for future studies on the role of this domain in pathogenesis.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":"56 1","pages":"110394"},"PeriodicalIF":4.8,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144337460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rag GTPases control lysosomal acidification by regulating v-ATPase assembly in Drosophila.","authors":"Ying Zhou,Xiaodie Yang,Wenyu Xu,Sulin Shen,Weikang Fan,Guoqiang Meng,Yang Cheng,Yingying Lu,Youheng Wei","doi":"10.1016/j.jbc.2025.110400","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110400","url":null,"abstract":"The Rag GTPases play an important role in sensing amino acids and activating the target of rapamycin complex 1 (TORC1), a master regulator of cell metabolism. Previously, we have shown that GDP-bound RagA stimulates lysosome acidification and autophagic degradation, which are essential for young egg chamber survival under starvation in Drosophila. However, the underlying mechanism is unclear. Here we demonstrate that the GDP-bound RagA breaks the physical interaction between chaperonin containing tailless complex polypeptide 1 (CCT) and Vacuolar H+-ATPase (v-ATPase) subunit V1, and thus promotes the assembly of active v-ATPase and increases the lysosomal acidification. Consistently, knockdown of CCT complex components rescued the accumulation of defective autolysosomes in RagA RNAi. Moreover, the knockdown of Lamtor4, a component of lysosomal adaptor and MAPK and mTOR activator (LAMTOR) that anchors Rag GTPases to the lysosome, resulted in autolysosome accumulation, suggesting that RagGTPases regulate lysosomal acidification depend on their lysosomal localization. Knockdown of the CCT complex components attenuated the autophagic defects in Lamtor 4 RNAi. Our work highlights the interaction between CCT and v-ATPase in regulating lysosomal acidification.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":"70 1","pages":"110400"},"PeriodicalIF":4.8,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144337466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}