Biochemical Journal最新文献_第3页

Allosteric regulation of proteolytic machines unveiled by the synergy between cryo-EM and solution NMR spectroscopy. 低温电镜和溶液核磁共振波谱的协同作用揭示了蛋白水解机器的变构调节。

IF 4.3 3区生物学

Biochemical Journal Pub Date : 2025-08-26 DOI: 10.1042/BCJ20253239

Madison Turner, Robert W Harkness, Zev A Ripstein, Rui Huang, Siavash Vahidi

{"title":"Allosteric regulation of proteolytic machines unveiled by the synergy between cryo-EM and solution NMR spectroscopy.","authors":"Madison Turner, Robert W Harkness, Zev A Ripstein, Rui Huang, Siavash Vahidi","doi":"10.1042/BCJ20253239","DOIUrl":"10.1042/BCJ20253239","url":null,"abstract":"Mechanistic studies of biomolecular machines involved in intracellular protein degradation-such as the caseinolytic protease P, ATPases associated with diverse cellular activities (AAA+) motors, and the high-temperature requirement A family of enzymes-are of great interest as they are implicated in a host of human diseases. The function of these systems is dependent on both their fine-tuned three-dimensional structure and the conformational dynamics that modulate this structure. Their large sizes, inherent conformational plasticity, and oligomeric heterogeneity dictate that their mechanism of action cannot be deciphered by any one method. Synergistic application of methyl-transverse relaxation optimized spectroscopy (methyl-TROSY), nuclear magnetic resonance (NMR), and single-particle electron cryomicroscopy (cryo-EM) has uniquely positioned researchers to tackle the outstanding questions in this area of structural biology. Cryo-EM enables structural characterization and modeling of the large and conformationally heterogeneous complexes involved in protein degradation, while methyl-TROSY NMR enables monitoring structural transitions and conformational dynamics of these systems in response to various stimuli in solution at atomic resolution. This review highlights how combining these two approaches offers a distinct and powerful means to unravel allosteric pathways within complex, multipartite biomolecular machines.","PeriodicalId":8825,"journal":{"name":"Biochemical Journal","volume":"483 17","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12493191/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144940773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Lipid nanoparticle-delivered intrabodies for inhibiting necroptosis and pyroptosis. 脂质纳米颗粒递送体内抑制坏死和焦亡。

IF 4.3 3区生物学

Biochemical Journal Pub Date : 2025-08-20 DOI: 10.1042/BCJ20253191

Veerasikku Gopal Deepagan, Xiuquan Ma, Farzaneh Bazregari, Jiyi Pang, Jan Schaefer, Joanne M Hildebrand, Ruby K Dempsey, Marcel Doerflinger, Christopher A Baldwin, Florian I Schmidt, James M Murphy, Ranja Salvamoser, James E Vince

{"title":"Lipid nanoparticle-delivered intrabodies for inhibiting necroptosis and pyroptosis.","authors":"Veerasikku Gopal Deepagan, Xiuquan Ma, Farzaneh Bazregari, Jiyi Pang, Jan Schaefer, Joanne M Hildebrand, Ruby K Dempsey, Marcel Doerflinger, Christopher A Baldwin, Florian I Schmidt, James M Murphy, Ranja Salvamoser, James E Vince","doi":"10.1042/BCJ20253191","DOIUrl":"10.1042/BCJ20253191","url":null,"abstract":"Intrabodies are intracellularly expressed high-affinity protein binders such as nanobodies and monobodies that offer an alternative approach to small molecules. However, the maturation of intrabody technology into new therapeutic modalities has been limited by the availability of a clinically relevant delivery system enabling sufficiently high levels of protein to be expressed in the cytosol. Here, we use lipid nanoparticle (LNP) systems based on clinically approved formulations for the efficient intracellular delivery of mRNAs encoding for intrabodies targeting mixed lineage kinase domain-like pseudokinase (MLKL) and apoptosis-associated speck-like protein containing a CARD (ASC), key mediators of the necrotic cell death modalities, necroptosis and pyroptosis, respectively. LNP delivery of intrabody mRNA resulted in robust protein expression, with an MLKL-binding intrabody preventing MLKL membrane translocation and protecting against necroptotic cell death. Similarly, LNP delivery of a bivalent intrabody targeting the inflammasome adaptor protein ASC protected against NLRP3 and AIM2 inflammasome-driven responses, including caspase-1 and IL-1β activation and gasdermin D-driven pyroptotic killing. These findings establish that LNPs harbouring anti-necrotic intrabody mRNAs allow for sufficient intracellular expression to neutralize necrotic cell death signalling and provide a general, clinically relevant, strategy for delivering therapeutic intrabodies into cells.","PeriodicalId":8825,"journal":{"name":"Biochemical Journal","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12493153/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144815746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High tide or low tide: the transport and metabolism of mitochondrial nucleotides. 涨潮或退潮：线粒体核苷酸的转运和代谢。

IF 4.3 3区生物学

Biochemical Journal Pub Date : 2025-08-18 DOI: 10.1042/10.1042/BCJ20253237

Thomas MacVicar

{"title":"High tide or low tide: the transport and metabolism of mitochondrial nucleotides.","authors":"Thomas MacVicar","doi":"10.1042/10.1042/BCJ20253237","DOIUrl":"10.1042/10.1042/BCJ20253237","url":null,"abstract":"Mitochondria are multifaceted organelles that support numerous cellular metabolic pathways, including the biosynthesis of nucleotides required for cell growth and proliferation. Owing to an ancient endosymbiotic origin, mitochondria contain multiple copies of their own genome and therefore demand sufficient (deoxy)nucleotides in the mitochondrial matrix for DNA replication and transcription into RNA. Disturbed mitochondrial deoxynucleotide homeostasis can lead to a decline in mitochondrial DNA abundance and integrity, causing mitochondrial diseases with diverse and severe symptoms. Mitochondrial nucleotides are not only required for nucleic acid synthesis but also for bioenergetics and mitochondrial enzymatic activity. This review first explores how mitochondria supply energy and anabolic precursors for nucleotide synthesis and how the mitochondrial network influences the spatial control of cellular nucleotide metabolism. Then follows an in-depth discussion of the mechanisms that supply mitochondria with sufficient and balanced nucleotides and why these mechanisms are relevant to human mitochondrial disease. Lastly, the review highlights the emergence of regulated mitochondrial nucleotide supply in physiological processes including innate immunity and discusses the implications of dysregulated mitochondrial and cytosolic nucleotide homeostasis in pathophysiology.","PeriodicalId":8825,"journal":{"name":"Biochemical Journal","volume":"482 16","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144871208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Mutational insights into human kynurenine aminotransferase 1: modulation of transamination and β-elimination activities across diverse substrates. 人类犬尿氨酸转氨酶1的突变洞察：跨不同底物的转氨化和β消除活性的调节。

IF 4.3 3区生物学

Biochemical Journal Pub Date : 2025-08-18 DOI: 10.1042/BCJ20253178

Arun Kumar Selvam, Renhua Sun, Ali Razaghi, Hugh Salter, Tatiana Sandalova, Mikael Björnstedt, Adnane Achour

{"title":"Mutational insights into human kynurenine aminotransferase 1: modulation of transamination and β-elimination activities across diverse substrates.","authors":"Arun Kumar Selvam, Renhua Sun, Ali Razaghi, Hugh Salter, Tatiana Sandalova, Mikael Björnstedt, Adnane Achour","doi":"10.1042/BCJ20253178","DOIUrl":"10.1042/BCJ20253178","url":null,"abstract":"Human kynurenine aminotransferase 1 (hKYAT1) plays a crucial role in the transamination of aromatic amino acids and kynurenine. This promiscuous homodimeric enzyme transaminates various amino acids into their corresponding α-keto acids. Additionally, hKYAT1 is known to catalyze the β-elimination of cysteine-S conjugates and cysteine-Se conjugates. In this study, we performed mutational analyses of hKYAT1, targeting its catalytic, ligand-binding, and substrate-binding sites. The transamination activity of 13 mutant variants was systematically evaluated against sixteen different amino acid substrates, including kynurenine, selenomethionine (SeMet), and Se-methylselenocysteine (MSC), as well as for the β-elimination of SeMet and MSC. Our results demonstrate that mutations of residues E27 in the catalytic site and H279 in the substratestabilizing site significantly enhanced the transamination of several amino acids, including phenylalanine, tryptophan, histidine, and MSC. The H279F mutation increased transamination and β-elimination of MSC by 2- and 1.5-fold, respectively. Furthermore, mutation at the ligand-binding residues R398, F125, and N185 substantially reduced MSC transamination activity of hKYAT1. Interestingly, none of the tested mutations affected the transamination of l-kynurenine, a natural substrate of hKYAT1. Altogether, these findings support future investigation into hKYAT1 as a modifiable target in selenium-mediated anticancer approaches.","PeriodicalId":8825,"journal":{"name":"Biochemical Journal","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12493182/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144815747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High tide or low tide: the transport and metabolism of mitochondrial nucleotides. 涨潮或退潮：线粒体核苷酸的转运和代谢。

IF 4.3 3区生物学

Biochemical Journal Pub Date : 2025-08-18 DOI: 10.1042/BCJ20253237

Thomas MacVicar

{"title":"High tide or low tide: the transport and metabolism of mitochondrial nucleotides.","authors":"Thomas MacVicar","doi":"10.1042/BCJ20253237","DOIUrl":"10.1042/BCJ20253237","url":null,"abstract":"Mitochondria are multifaceted organelles that support numerous cellular metabolic pathways, including the biosynthesis of nucleotides required for cell growth and proliferation. Owing to an ancient endosymbiotic origin, mitochondria contain multiple copies of their own genome and therefore demand sufficient (deoxy)nucleotides in the mitochondrial matrix for DNA replication and transcription into RNA. Disturbed mitochondrial deoxynucleotide homeostasis can lead to a decline in mitochondrial DNA abundance and integrity, causing mitochondrial diseases with diverse and severe symptoms. Mitochondrial nucleotides are not only required for nucleic acid synthesis but also for bioenergetics and mitochondrial enzymatic activity. This review first explores how mitochondria supply energy and anabolic precursors for nucleotide synthesis and how the mitochondrial network influences the spatial control of cellular nucleotide metabolism. Then follows an in-depth discussion of the mechanisms that supply mitochondria with sufficient and balanced nucleotides and why these mechanisms are relevant to human mitochondrial disease. Lastly, the review highlights the emergence of regulated mitochondrial nucleotide supply in physiological processes including innate immunity and discusses the implications of dysregulated mitochondrial and cytosolic nucleotide homeostasis in pathophysiology.","PeriodicalId":8825,"journal":{"name":"Biochemical Journal","volume":"482 16","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12493167/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144871209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Functional and structural characterization of AtAbf43C: an exo-1,5-α-L-arabinofuranosidase from Acetivibrio thermocellus DSM1313. 热细胞活弧菌DSM1313的外显式1,5-α- l -阿拉伯糖氟葡萄糖苷酶AtAbf43C的功能和结构表征

IF 4.3 3区生物学

Biochemical Journal Pub Date : 2025-08-18 DOI: 10.1042/BCJ20253186

Joey L Galindo, Philip D Jeffrey, Angela Zhu, A James Link, Jonathan M Conway

{"title":"Functional and structural characterization of AtAbf43C: an exo-1,5-α-L-arabinofuranosidase from Acetivibrio thermocellus DSM1313.","authors":"Joey L Galindo, Philip D Jeffrey, Angela Zhu, A James Link, Jonathan M Conway","doi":"10.1042/BCJ20253186","DOIUrl":"10.1042/BCJ20253186","url":null,"abstract":"Acetivibrio thermocellus degrades diverse polysaccharides found in plant biomass using an array of glycoside hydrolase (GH) enzymes. Here, we describe the structure and function of AtAbf43C, an uncharacterized GH family 43 subfamily 26 (GH43_26) α-L-arabinofuranosidase (EC 3.2.1.55) from A. thermocellus. AtAbf43C is optimally active on para-nitrophenol-α-L-arabinofuranoside at pH 5.5 and 65 °C, making it the most thermophilic bacterial GH43_26 enzyme characterized to date. We solved high-resolution crystal structures of full-length AtAbf43C and its individual carbohydrate binding module family 42 (CBM42) and GH43 domains, including a structure with L-arabinofuranose molecules bound to the CBM42. The CBM42 domain adopts a typical β-trefoil fold, and the GH43 domain forms a canonical 5-bladed β-propeller, each resembling those in the mesophilic GH43_26 enzyme SaAraf43A from Streptomyces avermitilis (PDB 3AKH). However, AtAbf43C exhibits a unique domain organization, with the CBM42 at the N-terminus and the GH43 domain at the C-terminus, the reverse of the arrangement observed in SaAraf43A. Structural alignment enabled identification of the conserved catalytic triad (D168, D283, and E344) in AtAbf43C, which we confirmed experimentally with site-directed mutagenesis. The deep-narrow topology of the AtAbf43C GH43 binding pocket is consistent with exo activity on arabino-oligosaccharide (AOS) substrates. Indeed, liquid chromatography-mass spectrometry (LC-MS) analysis of polysaccharides and oligosaccharides hydrolyzed by AtAbf43C confirmed exo activity primarily toward α-1,5-linked AOSs. This suggests AtAbf43C contributes to the degradation of AOS released from arabinose-rich polysaccharides by other A. thermocellus enzymes. Together, these results expand our understanding of the structure-function of GH43_26 enzymes and their role in plant biomass deconstruction.","PeriodicalId":8825,"journal":{"name":"Biochemical Journal","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12493170/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144815745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Gut reactions and gut instincts: regulation of intestinal homeostasis by receptor guanylyl cyclase C (GC-C). 肠道反应和肠道本能：受体胍基环化酶C （GC-C）对肠道稳态的调节。

IF 4.1 3区生物学

Biochemical Journal Pub Date : 2025-08-13 DOI: 10.1042/bcj20253055

Avipsa Bose,Sandhya S Visweswariah

引用次数: 0

Evolution of the conformational ensemble and allosteric networks of apoptotic caspases in chordates. 脊索动物凋亡半胱天冬酶的构象集合和变构网络的演化。

IF 4.3 3区生物学

Biochemical Journal Pub Date : 2025-08-05 DOI: 10.1042/BCJ20250001

Isha Joglekar, Mithun Nag Karadi Giridhar, David A Diaz, Ankit Deo, A Clay Clark

{"title":"Evolution of the conformational ensemble and allosteric networks of apoptotic caspases in chordates.","authors":"Isha Joglekar, Mithun Nag Karadi Giridhar, David A Diaz, Ankit Deo, A Clay Clark","doi":"10.1042/BCJ20250001","DOIUrl":"10.1042/BCJ20250001","url":null,"abstract":"Apoptotic caspases exist not as static structures but as dynamic ensembles in solution, finely tuned by post-translational modifications and oligomerization. The fine-tuning of this ensemble by cellular cues allows caspases to influence not only apoptotic pathways but also the non-apoptotic pathways in which they are involved. These ensembles span a complex conformational landscape from well-characterized low-energy states captured in structural databases to transient high-energy intermediates that remain elusive and poorly understood. This limited structural view poses a major barrier to fully understanding how caspase activity is regulated and diversified across cellular contexts. To address this, we integrate evolutionary, folding, and mutational data with molecular dynamics simulations and network analysis to uncover a highly conserved residue network in structural space that has been faithfully passed on in sequence space over 500 million years of vertebrate evolution. This network encodes a high-energy intermediate consistently present in the ensemble of all present-day vertebrate apoptotic caspases. It not only guides folding but also scaffolds dynamic motions, functioning like a structural backbone that supports the ensemble. Building on this foundation, we identify differentially evolving networks surrounding the conserved core in initiator and effector caspase subfamilies. These variations provide thermodynamic insight into how initiators stabilize monomeric conformations while effectors favor dimeric states, revealing how evolution shapes ensembles to diversify function in protein families. Additionally, we discover conserved hub residues near an allosteric hotspot, distinct from the core network, that regulate the dynamics of surrounding evolving networks and act as control centers that modulate the conformational equilibrium within the apoptotic caspase ensemble.","PeriodicalId":8825,"journal":{"name":"Biochemical Journal","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12409990/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144697467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Structural Insights and Biophysical Characterization of p90RSK2:ERK2 complex. p90RSK2:ERK2复合物的结构见解和生物物理特性。

IF 4.1 3区生物学

Biochemical Journal Pub Date : 2025-07-25 DOI: 10.1042/bcj20253110

Evan Kobori,Hoang Nguyen,Jian Wu,Katherine Chen,Rodeon Malinovski,Susan Taylor

{"title":"Structural Insights and Biophysical Characterization of p90RSK2:ERK2 complex.","authors":"Evan Kobori,Hoang Nguyen,Jian Wu,Katherine Chen,Rodeon Malinovski,Susan Taylor","doi":"10.1042/bcj20253110","DOIUrl":"https://doi.org/10.1042/bcj20253110","url":null,"abstract":"Kinase domains are often flanked by flexible tails and intrinsically disordered regions (IDRs) that contain conserved motifs. The coordinated action and interplay of IDRs and folded kinase domains is necessary for the proper function of kinases and kinase complexes. Characterization of full length kinases and complexes is often challenging due to the flexible nature of flanking IDRs, yet necessary to fully understand their function and regulation. The p90 ribosomal S6 kinase (RSK) family is an unique kinase family with two distinct, functional kinase domains (NTK and CTK) flanked by flexible tails and a linker. RSK2 forms a stable complex with its activating kinase, ERK2, and here, we use multiple complementary techniques, HDXMS, cryoEM, and Alphafold modeling to study the full length RSK2:ERK2 complex. We find that broadly, ERK2 is more solvent protected than the NTK/CTK. The NTK N-lobe has quite high deuterium uptake, and analysis of published NTK crystal structures suggests that the NTK N-lobe is dynamic and can adopt a wide range of conformations. CryoEM reveals that the RSK2:ERK2 complex adopts a compact shape, and this is consistent with AlphaFold model of the complex hints at a possible additional interface between the NTK and ERK2. Collectively, our approach demonstrates that employing multiple complementary techniques can provide insight into the structure and biophysical characteristics of this challenging to study kinase complex.","PeriodicalId":8825,"journal":{"name":"Biochemical Journal","volume":"11 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144747817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Nitration-driven structural changes in Hsp90 linked to gain of pathological functions. 硝酸驱动的Hsp90结构变化与病理功能的获得有关。

IF 4.1 3区生物学

Biochemical Journal Pub Date : 2025-07-25 DOI: 10.1042/bcj20253230

Tilottama Chatterjee,Alfonso Taboada,Isabelle E Logan,Patience N Paul,Miranda Huerta,Patrick Reardon,Rafael Radi,Ari Zeida,Maria Clara Franco

{"title":"Nitration-driven structural changes in Hsp90 linked to gain of pathological functions.","authors":"Tilottama Chatterjee,Alfonso Taboada,Isabelle E Logan,Patience N Paul,Miranda Huerta,Patrick Reardon,Rafael Radi,Ari Zeida,Maria Clara Franco","doi":"10.1042/bcj20253230","DOIUrl":"https://doi.org/10.1042/bcj20253230","url":null,"abstract":"Protein tyrosine (Y) nitration is an oxidative modification that occurs in pathological conditions such as neurodegenerative diseases and solid tumors. Depending on the location of the tyrosine residue, nitration can modify protein structure and function and affect cellular processes. We previously showed that site-specific nitration of the molecular chaperone Heat shock protein 90 (Hsp90) leads to distinct pathological gain-of-function that cannot be compensated or overcome by native Hsp90. While Hsp90 nitrated on Y33 localizes in mitochondria and decreases mitochondrial metabolism, Hsp90 nitrated on Y56 activates the purinergic receptor and calcium channel P2X7, triggering downstream signaling pathways that can lead to either cell proliferation or apoptosis, depending on the cell type. Herein, using complementary biophysical, biochemical, and in silico methods, we show that nitration on Y33 and Y56 triggers significant site-dependent local and global structural changes, linked to changes in Hsp90 activity. Nitration of these critical residues led to destabilization of Hsp90 dimer and formation of stable oligomeric species, with differential effects on Hsp90 ATPase and chaperone holdase activities depending on the nitrated residue. Molecular dynamics simulations further support the impact of nitration on Y33 and Y56 on the ATP-lid dynamics and the interaction of ATP with R392, critical to Hsp90 ATPase activity. Establishing the molecular basis of nitration-induced structural changes in Hsp90 leading to disease-driving functions is the first step towards the development of therapeutic approaches selectively targeting these pathological variants of Hsp90.","PeriodicalId":8825,"journal":{"name":"Biochemical Journal","volume":"1 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144737420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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