Journal of Biological Chemistry最新文献_第7页

Artesunate enhances the efficacy of Enzalutamide in advanced prostate cancer. 青蒿琥酯增强恩杂鲁胺治疗晚期前列腺癌的疗效。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-26 DOI: 10.1016/j.jbc.2025.108458

Xinyi Wang, Jinghui Liu, Fengyi Mao, Yifan Kong, Qiongsi Zhang, Chaohao Li, Daheng He, Chi Wang, Yanquan Zhang, Ruixin Wang, Sally R Ellingson, Qiou Wei, Zhiguo Li, Xiaoqi Liu

{"title":"Artesunate enhances the efficacy of Enzalutamide in advanced prostate cancer.","authors":"Xinyi Wang, Jinghui Liu, Fengyi Mao, Yifan Kong, Qiongsi Zhang, Chaohao Li, Daheng He, Chi Wang, Yanquan Zhang, Ruixin Wang, Sally R Ellingson, Qiou Wei, Zhiguo Li, Xiaoqi Liu","doi":"10.1016/j.jbc.2025.108458","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108458","url":null,"abstract":"Prostate cancer (PCa) is one of the leading causes of death among men worldwide. Treatments targeting the androgen receptor (AR) pathway remain the standard therapy for PCa patients. Enzalutamide (ENZ), a second-generation AR inhibitor, was developed to treat castration-resistant prostate cancer (CRPC). However, while patients initially respond to ENZ, drug resistance typically develops within a few months. Artesunate (ART), a semi-synthetic derivative of the Artemisinin plant, is approved for anti-malaria treatment. In this study, we conducted an FDA-approved drug screening and identified Artesunate as a potential candidate for overcoming ENZ resistance in prostate cancer (ENZ-R PCa). Mechanistically, ART induces the degradation of c-Myc, enhancing the efficacy of ENZ. Additionally, patient dataset analysis revealed that c-Myc plays a significant role in developing ENZ resistance. To summarize, these findings suggest a novel therapeutic strategy for ENZ-resistant prostate cancer.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108458"},"PeriodicalIF":4.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143742894","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}

引用次数: 0

Flavin transferase ApbE: from discovery to applications. 黄素转移酶ApbE：从发现到应用。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-26 DOI: 10.1016/j.jbc.2025.108453

Xiaoman Fan, Marco W Fraaije

{"title":"Flavin transferase ApbE: from discovery to applications.","authors":"Xiaoman Fan, Marco W Fraaije","doi":"10.1016/j.jbc.2025.108453","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108453","url":null,"abstract":"ApbE is a unique, membrane-bound enzyme which covalently attaches a flavin cofactor to specific target proteins. This irreversible post-translational modification is crucial for proper functioning of various bacterial proteins. ApbEs have also been identified in archaea and eukaryotes. This review summarizes current knowledge on the structural and mechanistic properties of this unique protein-modifying enzyme and its recent applications. The relatively small flavin transferase is typically anchored to the outer membrane of bacteria and possesses a conserved flavin-binding domain and a catalytic domain. It recognizes a specific sequence motif of its target proteins, resulting in flavinylation of a threonine or serine. For flavinylation, it depends on magnesium and utilizes FAD as substrate to attach the FMN moiety to the target protein, analogous to phosphorylation. ApbE-mediated flavinylation supports critical bacterial respiratory and metabolic pathways. Recently, ApbE was also shown to be a versatile tool for selectively modifying proteins. Using the flavin-tagging approach, proteins can be decorated with FMN or other flavins. Furthermore, it was demonstrated that ApbE can be employed to turn natural noncovalent flavoproteins into covalent flavoproteins. In summary, ApbE is crucial for the maturation of various flavoproteins by catalyzing covalent flavinylation. While great progress has been made in understanding the role and mode of action of ApbE, there are still many bacterial proteins predicted to be flavinylated by ApbE for which their role is enigmatic. Also, exploration of the potential of ApbE as protein modification tool has just begun. Clearly, future research will generate new ApbE-related insights and applications.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108453"},"PeriodicalIF":4.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143742864","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}

引用次数: 0

A major Toxoplasma Serine Protease Inhibitor protects the parasite against gut-derived serine proteases and NETosis damage. 一个主要的弓形虫丝氨酸蛋白酶抑制剂保护寄生虫免受肠道丝氨酸蛋白酶和NETosis损伤。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-26 DOI: 10.1016/j.jbc.2025.108457

Maryam Saffarian, Julia D Romano, Michael E Grigg, Isabelle Coppens

{"title":"A major Toxoplasma Serine Protease Inhibitor protects the parasite against gut-derived serine proteases and NETosis damage.","authors":"Maryam Saffarian, Julia D Romano, Michael E Grigg, Isabelle Coppens","doi":"10.1016/j.jbc.2025.108457","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108457","url":null,"abstract":"Toxoplasmosis is a life-threatening opportunistic infection in immunocompromised patients, caused by the parasite Toxoplasma gondii. Infection is initiated through oral ingestion of Toxoplasma cysts that must survive the harsh environment of the gut to undergo excystation. Released parasites invade intestinal epithelial cells, and then disseminate throughout tissues for encystation, mainly in the brain. How Toxoplasma escapes destruction mediated by gastrointestinal proteases is poorly understood. T. gondii has nine genes encoding serine protease inhibitor proteins (TgPIs). TgPI-1 is highly expressed across all Toxoplasma strains and developmental stages and contains three domains for binding to various serine proteases. Here, we explore the role of TgPI-1 in protecting Toxoplasma against serine proteases in the gut and neutrophil-derived proteases in the lamina propria. TgPI-1 localizes to the parasite plasma membrane and cyst wall. We generated ΔTgPI-1 parasites, and the mutant is more sensitive to neutrophil elastase (NE), trypsin and chymotrypsin than WT. Neutrophils exposed to Toxoplasma release Neutrophil Extracellular Traps (NET) with strain-dependent morphologies, ranging from spiky to extended cloudy. TgPI-1 was detected on NET containing NE, and ΔTgPI-1 parasites are more susceptible to destruction by NETosis. In mice, ΔTgPI-1 parasites exhibit reduced infectivity, poor dissemination to abdominal organs, and lower cyst burden in the brain. These findings shed light on a strategy employed by Toxoplasma to counteract enzymatic antimicrobial defenses in gut tissues, highlighting potential avenues for controlling tissue dissemination of this medically significant parasite.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108457"},"PeriodicalIF":4.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143742893","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}

引用次数: 0

Signal termination of the chemokine receptor CCR9 is governed by an arrestin-independent phosphorylation mechanism. 趋化因子受体CCR9的信号终止是由一个不依赖于抑制蛋白的磷酸化机制控制的。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-26 DOI: 10.1016/j.jbc.2025.108462

Thomas D Lamme, Martine J Smit, Christopher T Schafer

{"title":"Signal termination of the chemokine receptor CCR9 is governed by an arrestin-independent phosphorylation mechanism.","authors":"Thomas D Lamme, Martine J Smit, Christopher T Schafer","doi":"10.1016/j.jbc.2025.108462","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108462","url":null,"abstract":"The chemokine receptor CCR9 coordinates immune cell migration from the thymus to the small intestine along gradients of the chemokine CCL25. Receptor dysregulation is associated with a variety of inflammatory bowel diseases such as Crohn's and ulcerative colitis, while aberrant CCR9 overexpression correlates with tumor metastasis. Despite being an attractive therapeutic target, attempts to clinically antagonize CCR9 have been unsuccessful. This highlights the need for a deeper understanding of its specific regulatory mechanisms and signaling pathways. CCR9 is a G protein-coupled receptor (GPCR) and activates Gi and Gq pathways. Unexpectedly, live-cell BRET assays reveal only limited G protein activation and signaling is rapidly terminated. Truncating the receptor C-terminus significantly enhanced G protein coupling, highlighting a regulatory role of this domain. Signal suppression was not due to canonical arrestin-coordinated desensitization. Rather, removal of GPCR kinase (GRK) phosphorylation led to sustained and robust G protein activation by CCR9. Using site-directed mutagenesis, we identified specific phosphorylation motifs that attenuate G protein coupling. Receptor internalization did not correlate with G protein activation capabilities. Instead, CCR9 phosphorylation disrupted the interaction of G protein heterotrimers with the receptor. This interference may lead to rapid loss of productive coupling and downstream signaling as phosphorylation would effectively render the receptor incapable of G protein coupling. An arrestin-independent, phosphorylation-driven deactivation mechanism could complement arrestin-dependent regulation of other GPCRs and have consequences for therapeutically targeting these receptors.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108462"},"PeriodicalIF":4.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143742950","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}

引用次数: 0

Spectroscopy and crystallography define carotenoid oxygenases as a new subclass of mononuclear non-heme Fe^II enzymes. 光谱学和晶体学将类胡萝卜素加氧酶定义为单核非血红素FeII酶的一个新亚类。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-25 DOI: 10.1016/j.jbc.2025.108444

Dory E DeWeese, Michael P Everett, Jeffrey T Babicz, Anahita Daruwalla, Edward I Solomon, Philip D Kiser

{"title":"Spectroscopy and crystallography define carotenoid oxygenases as a new subclass of mononuclear non-heme FeII enzymes.","authors":"Dory E DeWeese, Michael P Everett, Jeffrey T Babicz, Anahita Daruwalla, Edward I Solomon, Philip D Kiser","doi":"10.1016/j.jbc.2025.108444","DOIUrl":"10.1016/j.jbc.2025.108444","url":null,"abstract":"Carotenoid cleavage dioxygenases (CCDs) are non-heme FeII enzymes that catalyze the oxidative cleavage of alkene bonds in carotenoids, stilbenoids, and related compounds. How these enzymes control the reaction of O2 with their alkene substrates is unclear. Here, we apply spectroscopy in conjunction with X-ray crystallography to define the iron coordination geometry of a model CCD, CAO1, in its resting state and following substrate binding and coordination sphere substitutions. Resting CAO1 exhibits a five-coordinate (5C), square pyramidal FeII center that undergoes steric distortion towards a trigonal bipyramidal geometry in the presence of piceatannol. Titrations with the O2-analog, nitric oxide (NO), show a >100-fold increase in iron-NO affinity upon substrate binding, defining a crucial role for the substrate in activating the FeII site for O2 reactivity. The importance of the 5C FeII structure for reactivity was probed through mutagenesis of the second-sphere Thr151 residue of CAO1, which occludes ligand binding at the sixth coordination position. A T151G substitution resulted in the conversion of the iron center to a six-coordinate (6C) state and a 135-fold reduction in apparent catalytic efficiency towards piceatannol compared to the wild-type enzyme. Substrate complexation resulted in partial 6C to 5C conversion, indicating solvent dissociation from the iron center. Additional substitutions at this site demonstrated a general functional importance of the occluding residue within the CCD superfamily. Taken together, these data suggest an ordered mechanism of CCD catalysis occurring via substrate-promoted solvent replacement by O2. CCDs thus represent a new class of mononuclear non-heme FeII enzymes.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108444"},"PeriodicalIF":4.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143730055","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}

引用次数: 0

Low dose Taxol causes mitochondrial dysfunction in actively respiring cancer cells. 低剂量紫杉醇引起活跃呼吸癌细胞线粒体功能障碍。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-25 DOI: 10.1016/j.jbc.2025.108450

Rozhin Penjweini, Katie A Link, Shureed Qazi, Nikhil Mattu, Adam Zuchowski, Alexandra Vasta, Dan L Sackett, Jay R Knutson

{"title":"Low dose Taxol causes mitochondrial dysfunction in actively respiring cancer cells.","authors":"Rozhin Penjweini, Katie A Link, Shureed Qazi, Nikhil Mattu, Adam Zuchowski, Alexandra Vasta, Dan L Sackett, Jay R Knutson","doi":"10.1016/j.jbc.2025.108450","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108450","url":null,"abstract":"Mitochondrial oxygen consumption, dynamics and morphology play roles in the occurrence, development and drug resistance of cancer; thus they are main targets for many anticancer drugs. Increased mitochondrial oxygen consumption and impaired oxygen delivery creates hypoxia, which influences the balance of metabolic co-factors for biogenesis, disease progression and response to therapeutics. We therefore investigated the effects of Taxol, a well-known anticancer drug, on mitochondrial respiration (principally via a measure of oxidative phosphorylation (OXPHOS) versus glycolysis), morphology and dynamics. The concomitant effects of Taxol on mitochondrial adenosine triphosphate (ATP) and reactive oxygen species (ROS) production, mitochondrial membrane potential, radical-induced formation of carbonyl groups, mitochondrial release of cytochrome c, as well as cell cycle were investigated. Cells used in this study include: A549 (non-small cell lung epithelial cancer cell line), A549-ρ0 (mitochondrial DNA-depleted derivative of A549), and BEAS-2B (a non-cancer cell line derived from normal bronchial epithelium), as well as PC3 (prostate cancer) and HepG2 (hepatocellular carcinoma); these cell lines are known to have disparate metabolic profiles. Using a multitude of fluorescence-based measurements, we show that Taxol, even at a low dose, still adversely effects mitochondria of actively respiring (aerobic) cancer cells. We find an increase in mitochondrial ROS and cytochrome c release, suppression of ATP production and OXPHOS, fragmentation of the mitochondrial network and disruption of mitochondria-microtubule linkage. We find these changes in oxidative, but not glycolytic, cancer cells. Non-cancer cells, which are oxidative, do not show these changes.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108450"},"PeriodicalIF":4.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143730067","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}

引用次数: 0

The N-terminal ELR⁺ motif of the neutrophil attractant CXCL8 confers susceptibility to degradation by the Group A Streptococcal protease, SpyCEP. 中性粒细胞引诱剂CXCL8的n端ELR+基序使其易于被A群链球菌蛋白酶SpyCEP降解。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-25 DOI: 10.1016/j.jbc.2025.108448

Sean Patrick Giblin, Sophie McKenna, Stephen Matthews, Shiranee Sriskandan, James Edward Pease

{"title":"The N-terminal ELR+ motif of the neutrophil attractant CXCL8 confers susceptibility to degradation by the Group A Streptococcal protease, SpyCEP.","authors":"Sean Patrick Giblin, Sophie McKenna, Stephen Matthews, Shiranee Sriskandan, James Edward Pease","doi":"10.1016/j.jbc.2025.108448","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108448","url":null,"abstract":"Streptococcus pyogenes (Group A Streptococcus or GAS) is a major human pathogen, for which an effective vaccine is highly desirable. Invasive S.pyogenes strains evade the host immune response in part by producing a cell envelope protease, SpyCEP. This neutralises chemokines containing an N-terminal Glu-Leu-Arg motif (ELR+ chemokines) by cleavage at a distal C-terminal site within the chemokine. SpyCEP is a component of several S. pyogenes vaccines, yet the molecular determinants underlying substrate selectivity are poorly understood. We hypothesised that chemokine recognition and cleavage is a multi-step process, involving distinct domains of both substrate and enzyme. We generated a panel of recombinant CXCL8 variants where domains of the chemokine were exchanged or mutated. Chemokine degradation by SpyCEP was assessed by SDS-PAGE, Western blot and ELISA. Extension of the CXCL8 N-terminus was found to inhibit chemokine cleavage. Reciprocal exchanges of the N-termini of CXCL8 with that of the ELR- chemokine CXCL4 resulted in the generation of loss of function and gain of function substrates. This suggested a key role for the ELR motif in substrate recognition, which was supported directly by alanine substitution of the ELR motif of CXCL8, impairing the parameters, KM, Vmax and Kcat in kinetic assays with SpyCEP. Collectively, our findings identify the N-terminal ELR motif as a major determinant for recognition by SpyCEP and expose a vulnerability in the mechanism by which the protease recognises its substrates. This likely presents potential avenues for therapeutic intervention via targeted vaccine design and small molecule inhibition.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108448"},"PeriodicalIF":4.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143730129","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}

引用次数: 0

Role of SIRT3 in the regulation of Gadd45α expression and DNA repair in β-cells. SIRT3在β细胞中调控Gadd45α表达和DNA修复中的作用。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-25 DOI: 10.1016/j.jbc.2025.108451

Aaron Naatz, Kelsey S Bohl, Rachel A Jones Lipinski, Joshua A Nord, Alyssa L Gehant, Polly A Hansen, Brian C Smith, John A Corbett

{"title":"Role of SIRT3 in the regulation of Gadd45α expression and DNA repair in β-cells.","authors":"Aaron Naatz, Kelsey S Bohl, Rachel A Jones Lipinski, Joshua A Nord, Alyssa L Gehant, Polly A Hansen, Brian C Smith, John A Corbett","doi":"10.1016/j.jbc.2025.108451","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108451","url":null,"abstract":"In previous studies, we have shown that growth arrest and DNA damage (Gadd) 45α is required for the repair of nitric oxide-mediated DNA damage in β-cells. Gadd45α expression is stimulated by nitric oxide and requires forkhead box protein (Fox) O1 and NAD+-dependent deacetylase activity. Based on inhibitor studies, we attributed this activity to Sirtuin (SIRT)1; however, the inhibitors used in this previous study also attenuate the deacetylase activity of SIRT2, 3, and 6. We now provide experimental evidence that SIRT1 is dispensable for β-cell expression of Gadd45α and that the mitochondrial localized isoform SIRT3, is required for DNA repair in β-cells. We show that siRNA knockdown of Sirt3 attenuates nitric oxide-stimulated Gadd45α mRNA accumulation in both wildtype and Sirt1-/- INS 832/13 cells as well as isolated rat islets, and that SIRT3 inhibition increases FoxO1 acetylation and attenuates DNA repair in response to nitric oxide. While SIRT3 is predominantly localized to mitochondria, a small fraction is localized in the nucleus of insulin-containing cells and functions to participate in the regulation of FoxO1-dependent, nitric oxide-stimulated DNA repair.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108451"},"PeriodicalIF":4.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143730050","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}

引用次数: 0

Serine mistranslation induces the integrated stress response through the P stalk. 丝氨酸误译通过P柄诱导综合应力响应。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-25 DOI: 10.1016/j.jbc.2025.108447

Hong Zhang, Jiqiang Ling

{"title":"Serine mistranslation induces the integrated stress response through the P stalk.","authors":"Hong Zhang, Jiqiang Ling","doi":"10.1016/j.jbc.2025.108447","DOIUrl":"10.1016/j.jbc.2025.108447","url":null,"abstract":"Aminoacyl-tRNA synthetases (aaRSs) are essential enzymes that support robust and accurate protein synthesis. A rapidly expanding number of studies show that mutations in aaRSs lead to multiple human diseases, including neurological disorders and cancer. How aaRS mutations impact human health is not fully understood. In particular, our knowledge of how aminoacylation errors affect stress responses and fitness in eukaryotic cells remains limited. The integrated stress response (ISR) is an adaptive mechanism in response to multiple stresses. However, chronic activation of the ISR contributes to the development of multiple diseases such as neuropathies. In this study, we show that Ser misincorporation into Ala and Thr codons, resulting from either aaRS editing defects or mutations in tRNAs, actives the ISR. We further demonstrate that activation of the ISR by Ser mistranslation does not depend on the accumulation of uncharged tRNAs, but rather requires the P stalk associated with the ribosome, implying that ribosome stalling and collision are involved. Our work highlights that certain types of aminoacylation errors can lead to chronic activation of the ISR, potentially affecting fitness and disease progression.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108447"},"PeriodicalIF":4.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143730052","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}

引用次数: 0

Unstructured protein domains stabilize RNA binding and mediate RNA folding by AUF1. 非结构化蛋白结构域稳定RNA结合并介导RNA折叠。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-25 DOI: 10.1016/j.jbc.2025.108442

Nina C Lee, Haley H Tilley, Grace A Acle, Patrick J McGinnis, Gerald M Wilson

{"title":"Unstructured protein domains stabilize RNA binding and mediate RNA folding by AUF1.","authors":"Nina C Lee, Haley H Tilley, Grace A Acle, Patrick J McGinnis, Gerald M Wilson","doi":"10.1016/j.jbc.2025.108442","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108442","url":null,"abstract":"AUF1 is an RNA-binding protein that targets AU-rich elements (AREs), cis-acting regulatory sequences commonly enriched in mRNAs encoding inflammatory mediators and oncoproteins. AUF1 post-transcriptionally regulates gene expression by modulating the stability and/or translational efficiency of mRNA targets in a context-specific manner; however, the mechanisms by which AUF1 directly engages RNA substrates and mediates regulatory outcomes remain largely unknown. The purpose of this study was to define the biochemical basis for RNA recognition by AUF1 using the smallest protein isoform (p37AUF1) as a model. AUF1 contains two tandem RNA recognition motifs (RRMs), common RNA-binding domains that stabilize formation of many ribonucleoprotein (RNP) complexes. Using quantitative fluorescence anisotropy-based assays, we observed that p37AUF1's tandem RRM domain only weakly binds ARE substrates. Testing a panel of protein mutants revealed that the N- and C-terminal flanking domains each make modest but similar contributions to stabilization of both the initial RNA:protein complex and a subsequent protein binding event. However, focused protein truncations showed that residues immediately N-terminal of the RRMs were vital for high affinity binding, but only in the context of the C-terminal domain. The C-terminal domain was also required for protein-induced RNA remodeling; both this function and its RNP-stabilizing role involve non-base-specific contacts with RNA upstream of the AU-rich motif. Finally, our data suggest that the C-terminal domain is intrinsically disordered but may undergo a conformational change upon interaction with RNA ligands. Together, these findings reveal distinct roles for flanking protein domains in RNA binding and remodeling by AUF1.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108442"},"PeriodicalIF":4.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143730104","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}

引用次数: 0