Journal of Biological Chemistry最新文献

The common murine retroviral integration site activating Hhex marks a distal regulatory enhancer co-opted in human Early T-cell precursor leukemia.

IF 4.8 2区生物学

Journal of Biological Chemistry Pub Date : 2025-01-27 DOI: 10.1016/j.jbc.2025.108233

Joyce Hardwick,Javier Rodriguez-Hernaez,Giovanni Gambi,Bryan J Venters,Yan Guo,Liqi Li,Paul E Love,Neal G Copeland,Nancy A Jenkins,Dimitrios Papaioannou,Iannis Aifantis,Aristotelis Tsirigos,Mircea Ivan,Utpal P Davé

{"title":"The common murine retroviral integration site activating Hhex marks a distal regulatory enhancer co-opted in human Early T-cell precursor leukemia.","authors":"Joyce Hardwick,Javier Rodriguez-Hernaez,Giovanni Gambi,Bryan J Venters,Yan Guo,Liqi Li,Paul E Love,Neal G Copeland,Nancy A Jenkins,Dimitrios Papaioannou,Iannis Aifantis,Aristotelis Tsirigos,Mircea Ivan,Utpal P Davé","doi":"10.1016/j.jbc.2025.108233","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108233","url":null,"abstract":"The Hhex gene encodes a transcription factor that is important for both embryonic and post-natal development, especially of hematopoietic tissues. Hhex is one of the most common sites of retroviral integration in mouse models. We found the most common integrations in AKXD (recombinant inbred strains) T-ALLs occur 57-61kb 3' of Hhex and activate Hhex gene expression. The genomic region of murine leukemia virus (MLV) integrations has features of a developmental stage-specific cis regulatory element (CRE), as evidenced by ATAC-seq in murine progenitor cells and high H3K27 acetylation at the syntenic CRE in human hematopoietic cell lines. With ChIP-exonuclease, we describe occupancy of LIM domain binding protein 1 (LDB1), the constitutive partner of the LIM Only-2 (LMO2), GATA1, and TAL1 transcription factors at GATA sites and a composite GATA-E box within the CRE. With virtual 4C analysis, we observed looping between this +65kb CRE and the proximal intron 1 enhancer of HHEX in primary human ETP-ALLs and in normal progenitor cells. Our results show that retroviral integrations at intergenic sites can mark and take advantage of CREs. Specifically, in the case of HHEX activation, this newly described +65kb CRE is co-opted in the pathogenesis of ETP-ALL by the LMO2/LDB1 complex.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":"74 1","pages":"108233"},"PeriodicalIF":4.8,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143062091","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

Integrative in silico and biochemical analyses demonstrate direct Arl3-mediated ODA16 release from the intraflagellar transport machinery.

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-01-27 DOI: 10.1016/j.jbc.2025.108237

Jiaolong Wang, Rune T Kidmose, Niels Boegholm, Nevin K Zacharia, Mads B Thomsen, Anni Christensen, Tara Malik, Karl Lechtreck, Esben Lorentzen

{"title":"Integrative in silico and biochemical analyses demonstrate direct Arl3-mediated ODA16 release from the intraflagellar transport machinery.","authors":"Jiaolong Wang, Rune T Kidmose, Niels Boegholm, Nevin K Zacharia, Mads B Thomsen, Anni Christensen, Tara Malik, Karl Lechtreck, Esben Lorentzen","doi":"10.1016/j.jbc.2025.108237","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108237","url":null,"abstract":"Outer dynein arms (ODAs) are essential for ciliary motility and are preassembled in the cytoplasm before trafficking into cilia by intraflagellar transport (IFT). ODA16 is a key adaptor protein that links ODAs to the IFT machinery via a direct interaction with the IFT46 protein. However, the molecular mechanisms regulating the assembly, transport, and release of ODAs remain poorly understood. Here, we employ AlphaPulldown, an in silico screening method, to identify direct interactors of ODA16, including the dynein adaptor IDA3 and the small GTPase Arl3. We use structural modeling, biochemical, and biophysical assays on Chlamydomonas and human proteins to elucidate the interactions and regulatory mechanisms governing the IFT of ODAs. We identify a conserved N-terminal motif in Chlamydomonas IFT46 that mediates its binding to one side of the ODA16 structure. Biochemical dissection reveals that IDA3 and Arl3 bind to the same surface of ODA16 (the C-terminal β-propeller face), which is opposite to the IFT46 binding site, enabling them to dissociate ODA16 from IFT46, likely through an allosteric mechanism. Our findings provide mechanistic insights into the concerted actions of IFT and adaptor proteins in ODA transport and regulation.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108237"},"PeriodicalIF":4.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143065923","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

REDD1-dependent GSK3β signaling in podocytes promotes canonical NF-κB activation in diabetic nephropathy.

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-01-27 DOI: 10.1016/j.jbc.2025.108244

Siddharth Sunilkumar, Esma I Yerlikaya, Ashley VanCleave, Sandeep M Subrahmanian, Allyson L Toro, Scot R Kimball, Michael D Dennis

{"title":"REDD1-dependent GSK3β signaling in podocytes promotes canonical NF-κB activation in diabetic nephropathy.","authors":"Siddharth Sunilkumar, Esma I Yerlikaya, Ashley VanCleave, Sandeep M Subrahmanian, Allyson L Toro, Scot R Kimball, Michael D Dennis","doi":"10.1016/j.jbc.2025.108244","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108244","url":null,"abstract":"Increasing evidence supports the role of an augmented immune response in the early development and progression of renal complications caused by diabetes. We recently demonstrated that podocyte-specific expression of stress response protein regulated in development and DNA damage response 1 (REDD1) contributes to activation of the pro-inflammatory transcription factor NF-κB in the kidney of diabetic mice. The studies here were designed to define the specific signaling events whereby REDD1 promotes NF-κB activation in the context of diabetic nephropathy. Streptozotocin (STZ)-induced diabetes promoted activation of glycogen synthase kinase 3β (GSK3β) in the kidney, which was prevented by REDD1 ablation. REDD1 was necessary and sufficient to enhance GSK3β activity in human podocyte cultures exposed to hyperglycemic conditions. GSK3β suppression prevented NF-κB activation and normalized the expression of pro-inflammatory factors in podocytes exposed to hyperglycemic conditions. In the kidneys of diabetic mice and in podocytes exposed to hyperglycemic conditions, REDD1-dependent GSK3β signaling promoted activation of the inhibitor of κB (IκB) kinase (IKK) complex upstream of NF-κB. GSK3β knockdown in podocytes exposed to hyperglycemic conditions reduced macrophage chemotaxis. Similarly, in diabetic mice treated with a GSK3 inhibitor, immune cell infiltration in the kidneys was reduced. Overall, the data support a model wherein hyperglycemia amplifies the activation of GSK3β in a REDD1-dependent manner, leading to canonical NF-κB signaling and an augmented renal immune response in diabetic nephropathy.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108244"},"PeriodicalIF":4.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143065927","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 yeast checkpoint kinase Dun1p represses transcription of RNR genes independently of catalytic activity or Rad53p during respiratory growth.

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-01-27 DOI: 10.1016/j.jbc.2025.108232

Shreya Nagar, Riddhi Mehta, Pritpal Kaur, Fatema Zohra Sadia, Suprataptha Reddy, Olasubomi R Olorunnimbe, Ivana Vancurova, Ales Vancura

{"title":"The yeast checkpoint kinase Dun1p represses transcription of RNR genes independently of catalytic activity or Rad53p during respiratory growth.","authors":"Shreya Nagar, Riddhi Mehta, Pritpal Kaur, Fatema Zohra Sadia, Suprataptha Reddy, Olasubomi R Olorunnimbe, Ivana Vancurova, Ales Vancura","doi":"10.1016/j.jbc.2025.108232","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108232","url":null,"abstract":"One of the key events in DNA damage response (DDR) is activation of checkpoint kinases leading to activation of ribonucleotide reductase (RNR) and increased synthesis of deoxyribonucleotide triphosphates (dNTPs), required for DNA repair. Among other mechanisms, the activation of dNTP synthesis is driven by derepression of genes encoding RNR subunits RNR2, RNR3, and RNR4, following checkpoint activation and checkpoint kinase Dun1p-mediated phosphorylation and inactivation of transcriptional repressor Crt1p. We report here that in the absence of genotoxic stress during respiratory growth on nonfermentable carbon source acetate, inactivation of checkpoint kinases results in significant growth defect and alters transcriptional regulation of RNR2-4 genes and genes encoding enzymes of the tricarboxylic acid (TCA) and glyoxylate cycles and gluconeogenesis. Dun1p, independently of its kinase activity or signaling from the upstream checkpoint kinase Rad53p, represses RNR2, RNR3, and RNR4 genes by maintaining Crt1p occupancy in the corresponding promoters. Consistently with the role of dNTPs in the regulation of mitochondrial DNA (mtDNA) copy number, DUN1 inactivation elevates mtDNA copy number in acetate-grown cells. Together, our data reveal an unexpected role for Dun1p in transcriptional regulation of RNR2-4 and metabolic genes during growth on nonfermentable carbon source and suggest that Dun1p contributes to transcription regulation independently of its kinase activity as a structural component by binding to protein(s) involved in gene regulation.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108232"},"PeriodicalIF":4.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143065653","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 conserved chaperone protein is required for the formation of a non-canonical type VI secretion system spike tip complex.

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-01-27 DOI: 10.1016/j.jbc.2025.108242

Kartik Sachar, Katarzyna Kanarek, Jake Colautti, Youngchang Kim, Eran Bosis, Gerd Prehna, Dor Salomon, John C Whitney

{"title":"A conserved chaperone protein is required for the formation of a non-canonical type VI secretion system spike tip complex.","authors":"Kartik Sachar, Katarzyna Kanarek, Jake Colautti, Youngchang Kim, Eran Bosis, Gerd Prehna, Dor Salomon, John C Whitney","doi":"10.1016/j.jbc.2025.108242","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108242","url":null,"abstract":"Type VI secretion systems (T6SS) are dynamic protein nanomachines found in Gram-negative bacteria that deliver toxic effector proteins into target cells in a contact-dependent manner. Prior to secretion, many T6SS effector proteins require chaperones and/or accessory proteins for proper loading onto the structural components of the T6SS apparatus. However, despite their established importance, the precise molecular function of several T6SS accessory protein families remains unclear. In this study, we set out to characterize the DUF2169 family of T6SS accessory proteins. Using gene co-occurrence analyses, we find that DUF2169-encoding genes strictly co-occur with genes encoding T6SS spike complexes formed by VgrG and 'PAAR-like' DUF4150 domains. Although structural similar to PAAR domains, DUF4150 domains lack PAAR motifs and instead contain a conserved PIPY motif, leading us to designate them PIPY domains. Next, we present both genetic and biochemical evidence that PIPY domains require a cognate DUF2169 protein to form a functional T6SS spike complex with VgrG. This contrasts with canonical PAAR proteins, which bind VgrG on their own to form functional spike complexes. By solving the first crystal structure of a DUF2169 protein, we show that this T6SS accessory protein adopts a novel protein fold. Furthermore, biophysical and structural modeling data suggest that DUF2169 contains a dynamic loop that physically interacts with a hydrophobic patch on the surface of its cognate PIPY domain. Based on these findings, we propose a model whereby DUF2169 proteins function as molecular chaperones that maintain VgrG-PIPY spike complexes in a secretion-competent state prior to their export by the T6SS apparatus.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108242"},"PeriodicalIF":4.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143065920","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

Synthetic mycolates derivatives to decipher protein mycoloylation, a unique post-translational modification in bacteria.

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-01-27 DOI: 10.1016/j.jbc.2025.108243

Emilie Lesur, Yijie Zhang, Nathalie Dautin, Christiane Dietrich, Ines Li de la Sierra-Gallay, Luis A Augusto, Paulin Rollando, Noureddine Lazar, Dominique Urban, Gilles Doisneau, Florence Constantinesco-Becker, Herman Van Tilbeurgh, Dominique Guianvarc'h, Yann Bourdreux, Nicolas Bayan

{"title":"Synthetic mycolates derivatives to decipher protein mycoloylation, a unique post-translational modification in bacteria.","authors":"Emilie Lesur, Yijie Zhang, Nathalie Dautin, Christiane Dietrich, Ines Li de la Sierra-Gallay, Luis A Augusto, Paulin Rollando, Noureddine Lazar, Dominique Urban, Gilles Doisneau, Florence Constantinesco-Becker, Herman Van Tilbeurgh, Dominique Guianvarc'h, Yann Bourdreux, Nicolas Bayan","doi":"10.1016/j.jbc.2025.108243","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108243","url":null,"abstract":"Protein mycoloylation is a newly characterized post-translational modification (PTM) specifically found in Corynebacteriales, an order of bacteria that includes numerous human pathogens. Their envelope is composed of a unique outer membrane, the so-called mycomembrane made of very-long chain fatty acids, named mycolic acids. Recently, some mycomembrane proteins including PorA have been unambiguously shown to be covalently modified with mycolic acids in the model organism Corynebacterium glutamicum by a mechanism that relies on the mycoloyltransferase MytC. This PTM represents the first example of protein O-acylation in prokaryotes and the first example of protein modification by mycolic acid. Through the design and synthesis of trehalose monomycolate (TMM) analogs, we prove that i) MytC is the mycoloyltransferase directly involved in this PTM, ii) TMM, but not trehalose dimycolate (TDM), is a suitable mycolate donor for PorA mycoloylation, iii) MytC is able to discriminate between an acyl and a mycoloyl chain in vitro unlike other trehalose mycoloyltransferases. We also solved the structure of MytC acyl-enzyme obtained with a soluble short TMM analogs which constitutes the first mycoloyltransferase structure with a covalently linked to an authentic mycolic acid moiety. These data highlight the great conformational flexibility of the active site of MytC during the reaction cycle and pave the way for a better understanding of the catalytic mechanism of all members of the mycoloyltransferase family including the essential Antigen85 enzymes in Mycobacteria.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108243"},"PeriodicalIF":4.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143065685","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

Sensitive detection and propagation of brain-derived tau assemblies in HEK293 based wild-type tau seeding assays.

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-01-27 DOI: 10.1016/j.jbc.2025.108245

Melissa Huang, William A McEwan

引用次数: 0

PDE4 inhibitor rolipram represses hedgehog signaling via ubiquitin-mediated proteolysis of GLI transcription factors to regress breast cancer.

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-01-27 DOI: 10.1016/j.jbc.2025.108239

Arka Bagchi, Anuran Bhattacharya, Analava Bera, Deblina Basak, Urmi Chatterji, Arunima Biswas

{"title":"PDE4 inhibitor rolipram represses hedgehog signaling via ubiquitin-mediated proteolysis of GLI transcription factors to regress breast cancer.","authors":"Arka Bagchi, Anuran Bhattacharya, Analava Bera, Deblina Basak, Urmi Chatterji, Arunima Biswas","doi":"10.1016/j.jbc.2025.108239","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108239","url":null,"abstract":"Aberrant activation of the hedgehog (Hh) signaling pathway positively correlates with progression, invasion and metastasis of several cancers, including breast cancer. Although numerous inhibitors of the Hh signaling pathway are available, several oncogenic mutations of key components of the pathway, including Smoothened (Smo), have limited their capability to be developed as putative anti-cancer drugs. In this study, we have modulated the Hh signaling pathway in breast cancer using a specific FDA-approved phosphodiesterase 4 (PDE4) inhibitor rolipram. The results indicated that increased levels of cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA), due to the treatment with rolipram on MCF-7 and MDA-MB-231 cells, induced PKA-mediated ubiquitination of glioma-associated oncogene homolog 2 full length (GLI2FL) and GLI3FL, leading to their transformation to respective repressor forms. This in turn reduced the level of GLI1 transcription factor in a time-dependent manner. We have also shown that elevated levels of PKA reduced the level of phosphorylated glycogen synthase kinase 3β (GSK3β), which is known to augment PKA-mediated ubiquitination of GLI2FL and GLI3FL. Rolipram treatment also impaired wound healing and migration in both cell lines and significantly reduced tumor weight and volume in tumor-bearing mice. Histological analysis showed a reduction in multi-nucleated cells and cellular infiltration in the lungs of rolipram-treated mice. Moreover, rolipram decreased GLI1 levels in tumors by enhancing cAMP-PKA signaling. These findings suggest that rolipram effectively inhibits the Hh pathway downstream of Smo, offering potential as a therapeutic strategy for controlling breast cancer progression and metastasis, including both hormone-responsive and triple-negative subtypes.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108239"},"PeriodicalIF":4.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143065926","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 novel FOXM1-BCL2A1 axis determines unfavourable response to venetoclax in AML.

IF 4.8 2区生物学

Journal of Biological Chemistry Pub Date : 2025-01-27 DOI: 10.1016/j.jbc.2025.108240

Sanjeev Raghuwanshi,Ahmed Magdy,Nissim Hay,Andrei Gartel

{"title":"A novel FOXM1-BCL2A1 axis determines unfavourable response to venetoclax in AML.","authors":"Sanjeev Raghuwanshi,Ahmed Magdy,Nissim Hay,Andrei Gartel","doi":"10.1016/j.jbc.2025.108240","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108240","url":null,"abstract":"Forkhead box M1 (FOXM1), a Forkhead family transcription factor, is often overexpressed in a variety of human cancers, including AML and strongly associated with therapy resistance and unfavourable outcomes. In AML with NPM1 mutations NPM1/FOXM1 complex sequesters FOXM1 in the cytoplasm and confers favourable treatment outcomes for AML patients, because of FOXM1 inactivation. Inhibition of FOXM1 in AML cell lines and animal models of AML sensitizes AML cells to the Bcl2-inhibitor, venetoclax. In a recent study the upregulation of the BCL2-family protein, BCL2A1 conferred resistance to venetoclax and multiple venetoclax combinations.In this study, we investigated FOXM1/BCL2A1 axis and determined that FOXM1 specifically inhibits venetoclax-induced apoptosis in AML via upregulation of BCL2A1.The knockdown of BCL2A1 in AML in the presence of high levels of FOXM1 led to sensitization of AML cells to venetoclax, suggesting that BCL2A1 is a major target of FOXM1 responsible for resistance to venetoclax. Venetoclax in combination with FOXM1 inhibitor STL001 inhibited BCL2A1 and circumvented venetoclax resistance. Pharmacological inhibition of FOXM1/BCL2A1 axis represents a therapeutic strategy to sensitize AML cells to venetoclax-induced apoptosis.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":"15 1","pages":"108240"},"PeriodicalIF":4.8,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143062074","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

Structural insights into 2-oxindole-forming monooxygenase MarE: Divergent architecture and substrate positioning versus tryptophan dioxygenases.

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-01-27 DOI: 10.1016/j.jbc.2025.108241

Inchul Shin, Romie C Nguyen, Samuel R Montoya, Aimin Liu

{"title":"Structural insights into 2-oxindole-forming monooxygenase MarE: Divergent architecture and substrate positioning versus tryptophan dioxygenases.","authors":"Inchul Shin, Romie C Nguyen, Samuel R Montoya, Aimin Liu","doi":"10.1016/j.jbc.2025.108241","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108241","url":null,"abstract":"MarE, a heme-dependent enzyme, catalyzes a unique 2-oxindole-forming monooxygenation reaction from tryptophan metabolites. To elucidate its enzyme-substrate interaction mode, we present the first X-ray crystal structures of MarE in complex with its prime substrate, (2S,3S)-β-methyl-L-tryptophan and cyanide at 1.89 Å resolution as well as a truncated yet catalytically active version in complex with the substrate at 2.45 Å resolution. These structures establish MarE as a member of the heme-dependent aromatic oxygenase (HDAO) superfamily and reveal its evolutionary link to indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO). While MarE adopts a global structure resembling the homotetrameric TDO, it features a simplified α6 helix compared to TDO's more elaborate αE and αH helices with additional αF and αG regions. Despite differing oxygen activation outcomes, MarE shares a substrate binding mode similar to IDO and TDO, with the indole nitrogen of its substrate oriented toward the heme iron in the ternary cyano complex, interacting with His55. The substrate's carboxylate group engages Arg118, with mutational studies confirming the roles of these residues in substrate binding. However, the second-sphere interactions with the substrate's α-amino nitrogen differ between MarE and TDO, and the substrate's orientation in the binary complex remains ambiguous due to two possible conformations. Notably, TDO features an extensive hydrogen-bonding network around the heme propionate below the heme plane, which is absent in MarE, suggesting mechanistic differences. These structural insights lay a foundation for further mechanistic studies, particularly for understanding how heme-dependent enzymes oxygenate tryptophan-derived metabolites.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108241"},"PeriodicalIF":4.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143065570","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