The FEBS journal最新文献_第9页

FXR suppress Müller cell activation by regulating cGAS/STING pathway in diabetic retinopathy.

The FEBS journal Pub Date : 2025-02-11 DOI: 10.1111/febs.17421

Zi-Li Wang, Xin-Yu Zhang, Cheng-Ye Tan, Miao Zhuang, Lingpeng Zhu, Xin-Hua Zheng, Yong Yao, Ting-Ting Wei

{"title":"FXR suppress Müller cell activation by regulating cGAS/STING pathway in diabetic retinopathy.","authors":"Zi-Li Wang, Xin-Yu Zhang, Cheng-Ye Tan, Miao Zhuang, Lingpeng Zhu, Xin-Hua Zheng, Yong Yao, Ting-Ting Wei","doi":"10.1111/febs.17421","DOIUrl":"https://doi.org/10.1111/febs.17421","url":null,"abstract":"Diabetic retinopathy (DR) is widely acknowledged as an ocular complication of diabetes mellitus involving retinal inflammation and secondary neuro/microvascular degeneration. Müller glial cells play a crucial role in regulating retinal homeostasis and neuroinflammation within the retina. Farnesoid X nuclear receptor (FXR) has emerged as a potential regulator of metabolic homeostasis and inflammatory responses as a bile acid nuclear receptor. However, its precise role in DR remains unclear. In order to investigate the effect of FXR on DR, we employed Sprague-Dawley rats treated with streptozotocin (STZ) and human Müller glial cells treated with advanced glycation end products (AGEs) or high glucose with palmitate (HG + PA). Our investigations revealed downregulation of FXR in DR. Furthermore, we demonstrated that activating FXR could mitigate the progression of DR, with its protective effects linked to the inhibition of inflammatory responses within Müller cells. Mechanistically, FXR could ameliorate mitochondrial dysfunction and suppress the opening of the mitochondrial permeability transition pore. This action blocked the release of mitochondrial DNA (mtDNA) from the mitochondria into the cytoplasm, thereby inhibiting the abnormal activation of the cGAS/STING pathway in DR. Further studies revealed that FXR upregulates mitochondrial transcription factor A (TFAM) by modulating ATF4/NRF1, ultimately enhancing mitochondrial function. Knockdown of FXR reversed the above effects. Additionally, FXR activation effectively rescued mitochondrial dysfunction, as evidenced by Tunicamycin (TUN)-mediated assays, further validating our findings. In summary, our findings suggest that targeting FXR may offer promising strategies for future therapeutic interventions in the treatment of DR.","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143392801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

α-Ketoglutarate inhibits the pluripotent-to-totipotent state transition in stem cells.

The FEBS journal Pub Date : 2025-02-10 DOI: 10.1111/febs.70008

Mengran Yin, Yan Li, Zhenzhu Sun, Xinyu Wu, Liang Ding, Qiang Zhang, Hai Zhou, Man Zhang, Dajiang Qin, Baoming Qin, Lulu Wang

{"title":"α-Ketoglutarate inhibits the pluripotent-to-totipotent state transition in stem cells.","authors":"Mengran Yin, Yan Li, Zhenzhu Sun, Xinyu Wu, Liang Ding, Qiang Zhang, Hai Zhou, Man Zhang, Dajiang Qin, Baoming Qin, Lulu Wang","doi":"10.1111/febs.70008","DOIUrl":"https://doi.org/10.1111/febs.70008","url":null,"abstract":"In early mouse embryogenesis, the distinct enrichment of α-ketoglutarate (αKG) in blastocysts and L-2-hydroxyglutarate (L-2HG) in 2-cell (2C) embryos serves as a key metabolic signature. While elevated L-2HG levels inhibit the resolution of totipotency during the transition from the 2C stage to the blastocyst, the role of αKG remains elusive. Mouse embryonic stem cells (mESCs) cultured in vitro naturally harbor a subpopulation that transitions dynamically into a 2C-like totipotent state, providing a convenient model to investigate the role of αKG in totipotency reprogramming. This study demonstrates that αKG significantly inhibits the pluripotency to totipotency transition through upregulating ten-eleven translocation (TET) DNA hydroxylases. We further show that reducing endogenous αKG levels via glutamine withdrawal or inhibiting αKG-dependent dioxygenases by blocking succinate dehydrogenase (SDH) markedly enhances the induction of 2C-like cells (2CLCs). Finally, leveraging the potent SDH inhibitor dimethyl malonate (DMM), we have developed a highly efficient protocol for 2CLC induction, producing cells that transcriptionally resemble mid-to-late 2C embryos. Our findings deepen the understanding of the metabolic regulation of totipotency and provide a previously undescribed approach for capturing totipotent-like stem cells in vitro.","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143392825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Structure predictions of MuRF1-UBE2 complexes identify amino acid residues governing interaction selectivity for each MuRF1-E2 pair.

The FEBS journal Pub Date : 2025-02-10 DOI: 10.1111/febs.70017

Agnès Claustre, Mélodie Malige, Maëlys Macheton, Lydie Combaret, Etienne Lefai, Pierre Fafournoux, Daniel Taillandier, Julien Henri, Cécile Polge

{"title":"Structure predictions of MuRF1-UBE2 complexes identify amino acid residues governing interaction selectivity for each MuRF1-E2 pair.","authors":"Agnès Claustre, Mélodie Malige, Maëlys Macheton, Lydie Combaret, Etienne Lefai, Pierre Fafournoux, Daniel Taillandier, Julien Henri, Cécile Polge","doi":"10.1111/febs.70017","DOIUrl":"https://doi.org/10.1111/febs.70017","url":null,"abstract":"The RING-type E3 ubiquitin-protein ligase MuRF1 (also known as TRIM63) plays an important role in skeletal muscle atrophy by targeting contractile proteins. In cellulo, MuRF1 can alternatively interact with four E2 enzymes (UBE2E1, UBE2J1, UBE2J2, or UBE2L3), suggesting different functions or targets for the four MuRF1-E2 complexes. In this article, we studied the interface of these MuRF1-UBE2 complexes based on AlphaFold2 and AlphaFold3 predictions. These predictions revealed the involvement of different residues at the interface of each complex. We confirmed this overall interface difference by the differential sensitivity of MuRF1-E2 complexes to regenerating solutions in surface plasmon resonance experiments. We further confirmed several predictions individually by affinity measurements with point-mutant E2 enzymes and truncated MuRF1. We used the interaction-induced fluorescence change approach with fluorescent MuRF1. Besides canonical E2-RING-type E3 interactions, we were able to identify selective contact points between MuRF1 and its UBE2 partners. Furthermore, in the case of the MuRF1-E2E1 pair, unlike the other MuRF1-E2 pairs, the interaction may also be governed by a domain outside the RING domain. Since the function of RING-type E3s is regulated by E2 enzymes, deciphering the mechanisms of selective recruitment of E2s by MuRF1 paves the way for the development of targeted therapeutics to fight muscle atrophy.","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143392821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Molecular mechanisms of hotspot variants in cytoskeletal β-actin associated with Baraitser-Winter syndrome.

The FEBS journal Pub Date : 2025-02-10 DOI: 10.1111/febs.70018

Johannes N Greve, Dietmar J Manstein

{"title":"Molecular mechanisms of hotspot variants in cytoskeletal β-actin associated with Baraitser-Winter syndrome.","authors":"Johannes N Greve, Dietmar J Manstein","doi":"10.1111/febs.70018","DOIUrl":"https://doi.org/10.1111/febs.70018","url":null,"abstract":"Baraitser-Winter cerebrofrontofacial syndrome (BWCFF) is the most common and best-defined clinical entity associated with heterozygous single-point missense mutations in cytoskeletal β-actin. Patients present with distinct craniofacial anomalies and neurodevelopmental disabilities of variable severity. To date, the most frequently observed variants affect residue R196 of cytoskeletal β-actin. Patients carrying the p.R196 variants are likely to suffer from pachygyria, probably due to neuronal migration defects contributing to the development of abnormal convolutions of the cerebral cortex. Here, we report on the recombinant production, purification and characterization of the BWCFF hotspot variants p.R196H, p.R196C and p.R196S. Our findings reveal that the stability of the monomeric variants remains unaffected, suggesting that the disease mechanism involves the incorporation of these variants into actin filaments. This incorporation alters F-actin stability and polymerization dynamics to varying degrees, depending on the specific variant. These effects are consistent with the positioning of residue R196 near the helical filament axis. Observed changes include an increased critical concentration for polymerization, reduced elongation rates and accelerated filament depolymerization. Within the actin-related protein 2/3 (Arp2/3)-generated branch junction complex, which is critical for processes such as cell migration and endocytosis, residue R196 is located at the interface between the first protomer of the nucleated filament and the Arp2 subunit. Variant p.R196H specifically results in reduced branching efficiency and impaired branch stability. Future research will seek to elucidate the impact of these actin filament defects on cellular processes and their contribution to the multifaceted pathophysiology of BWCFF, with a particular emphasis on cortical development.","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143392805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Phosphatidic acid induces cytoskeletal rearrangements through the Src-FAK-RhoA/ROCK signaling pathway during decidualization.

The FEBS journal Pub Date : 2025-02-10 DOI: 10.1111/febs.17412

Hyeon-Jeong Jun, So Young Lee, Shin-Young Park, Joong Sub Choi, Mee-Sup Yoon, Joong-Soo Han

{"title":"Phosphatidic acid induces cytoskeletal rearrangements through the Src-FAK-RhoA/ROCK signaling pathway during decidualization.","authors":"Hyeon-Jeong Jun, So Young Lee, Shin-Young Park, Joong Sub Choi, Mee-Sup Yoon, Joong-Soo Han","doi":"10.1111/febs.17412","DOIUrl":"https://doi.org/10.1111/febs.17412","url":null,"abstract":"Decidualization, the transformation of human endometrial stromal cells from a fibroblast-like to a rounded morphology, is crucial for creating a receptive intrauterine environment that supports successful embryo implantation. While decidual markers such as insulin-like growth factor-binding protein 1 and prolactin are well studied, the specific signaling mechanisms underlying morphological changes during decidualization remain unclear. In this study, we identified the phosphatidic acid (PA)-Src-focal adhesion kinase (FAK)-RhoA/Rho-associated protein kinase (ROCK) signaling pathway as a critical regulator of cytoskeletal rearrangement during PA-induced decidualization in human endometrial stromal cells. PA, a product of phospholipase D1, activates FAK, initiating a cascade of events involving Src-family kinases and RhoA signaling, ultimately leading to the cytoskeletal changes necessary for decidualization. Our in vitro experiments showed that PA-induced decidualization involved the formation of stress fibers mediated by ROCK activation. The traditional decidual markers, insulin-like growth factor-binding protein 1 and prolactin, did not significantly influence these morphological changes, suggesting that the PA-induced pathway operates independently of these markers. In vivo studies in ovariectomized mice demonstrated that PA injection into the uterine horn increased the uterine cavity weight and wall thickness, reinforcing the role of PA in promoting decidualization. These findings highlight the importance of the PA-Src-FAK-RhoA-ROCK pathway in regulating cytoskeletal dynamics during decidualization and suggest potential therapeutic targets for addressing implantation-associated infertility.","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143384405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Activating AMPK improves pathological phenotypes due to mtDNA depletion.

The FEBS journal Pub Date : 2025-02-07 DOI: 10.1111/febs.70006

Gustavo Carvalho, Tran V H Nguyen, Bruno Repolês, Josefin M E Forslund, W M Ruchitha Rukmal Wijethunga, Farahnaz Ranjbarian, Isabela C Mendes, Choco Michael Gorospe, Namrata Chaudhari, Micol Falabella, Mara Doimo, Sjoerd Wanrooij, Robert D S Pitceathly, Anders Hofer, Paulina H Wanrooij

{"title":"Activating AMPK improves pathological phenotypes due to mtDNA depletion.","authors":"Gustavo Carvalho, Tran V H Nguyen, Bruno Repolês, Josefin M E Forslund, W M Ruchitha Rukmal Wijethunga, Farahnaz Ranjbarian, Isabela C Mendes, Choco Michael Gorospe, Namrata Chaudhari, Micol Falabella, Mara Doimo, Sjoerd Wanrooij, Robert D S Pitceathly, Anders Hofer, Paulina H Wanrooij","doi":"10.1111/febs.70006","DOIUrl":"https://doi.org/10.1111/febs.70006","url":null,"abstract":"AMP-activated protein kinase (AMPK) is a master regulator of cellular energy homeostasis that also plays a role in preserving mitochondrial function and integrity. Upon a disturbance in the cellular energy state that increases AMP levels, AMPK activity promotes a switch from anabolic to catabolic metabolism to restore energy homeostasis. However, the level of severity of mitochondrial dysfunction required to trigger AMPK activation is currently unclear, as is whether stimulation of AMPK using specific agonists can improve the cellular phenotype following mitochondrial dysfunction. Using a cellular model of mitochondrial disease characterized by progressive mitochondrial DNA (mtDNA) depletion and deteriorating mitochondrial metabolism, we show that mitochondria-associated AMPK becomes activated early in the course of the advancing mitochondrial dysfunction, before any quantifiable decrease in the ATP/(AMP + ADP) ratio or respiratory chain activity. Moreover, stimulation of AMPK activity using the specific small-molecule agonist A-769662 alleviated the mitochondrial phenotypes caused by the mtDNA depletion and restored normal mitochondrial membrane potential. Notably, the agonist treatment was able to partially restore mtDNA levels in cells with severe mtDNA depletion, while it had no impact on mtDNA levels of control cells. The beneficial impact of the agonist on mitochondrial membrane potential was also observed in cells from patients suffering from mtDNA depletion. These findings improve our understanding of the effects of specific small-molecule activators of AMPK on mitochondrial and cellular function and suggest a potential application for these compounds in disease states involving mtDNA depletion.","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143367215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Structural analysis of the ribosome assembly factor Nep1, an N1-specific pseudouridine methyltransferase, reveals mechanistic insights.

The FEBS journal Pub Date : 2025-02-07 DOI: 10.1111/febs.70005

Sayan Saha, Shankar Prasad Kanaujia

{"title":"Structural analysis of the ribosome assembly factor Nep1, an N1-specific pseudouridine methyltransferase, reveals mechanistic insights.","authors":"Sayan Saha, Shankar Prasad Kanaujia","doi":"10.1111/febs.70005","DOIUrl":"https://doi.org/10.1111/febs.70005","url":null,"abstract":"Nucleolar essential protein 1 (Nep1; also known as ribosomal RNA small subunit methyltransferase Nep1) is a crucial factor in forming small ribosomal subunits in eukaryotes and archaea. Nep1 possesses an S-adenosyl-L-methionine (SAM)-dependent SpoU-TrmD (SPOUT) ribosomal RNA (rRNA) methyltransferase (MTase) fold and catalyzes pseudouridine (Ψ) methylation at specific sites of the small subunit (SSU) rRNA. Mutations in Nep1 proteins result in a severe developmental disorder in humans and reduced growth in yeast, suggesting its role in ribosome biogenesis. In this study, the crystal structures of Nep1 from the archaebacterium Pyrococcus horikoshii (PhNep1), both in its apo and holo (adenosine or 5-methylthioadenosine bound) forms have been reported. The structural analysis of PhNep1 revealed an α/β fold featuring a deep trefoil knot akin to the SPOUT domain, with two novel extensions-a globular loop and a β-α-β extension. Moreover, the cofactor-binding site of PhNep1 exhibits a preformed pocket, topologically similar to that of other SPOUT-class MTases. Further, structural analysis of PhNep1 revealed that it forms a homodimer coordinated by inter-subunit hydrogen bonds and hydrophobic interactions. Moreover, the results of this study indicate that PhNep1 can specifically methylate consensus RNAs, having a pseudouridine (ψ) located at position 926 of helix 35 (h35) of 16S rRNA in P. horikoshii. The stability of the Nep1-RNA complex seems to be primarily assisted by the conserved arginine residues located at the dimeric interface.","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143367217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Shifting the substrate scope of dimeric pyranose oxidase from monosaccharide to glycoside preference through oligomeric state modification.

The FEBS journal Pub Date : 2025-02-06 DOI: 10.1111/febs.70004

Anja Kostelac, Enikő Hermann, Clemens Peterbauer, Chris Oostenbrink, Dietmar Haltrich

{"title":"Shifting the substrate scope of dimeric pyranose oxidase from monosaccharide to glycoside preference through oligomeric state modification.","authors":"Anja Kostelac, Enikő Hermann, Clemens Peterbauer, Chris Oostenbrink, Dietmar Haltrich","doi":"10.1111/febs.70004","DOIUrl":"https://doi.org/10.1111/febs.70004","url":null,"abstract":"Pyranose oxidase (POx) and C-glycoside oxidase (CGOx) are FAD-dependent oxidoreductases belonging to the glucose-methanol-choline oxidoreductase superfamily and share the same sequence space. Despite a shared structural fold, these two members possess homologous domains that enable (arm and head domain) or disable (insertion-1 domain and barrel-shaped bottom) oligomerization. POxs with a higher oligomerization state (dimeric or tetrameric) exclusively catalyze the oxidation of monosaccharides (d-glucose, d-xylose). In contrast, the monomeric state of POxs/CGOxs is observed to prefer glycosides (homoorientin, phlorizin) and has low activity with free monosaccharides. We aimed to engineer dimeric POx from Kitasatospora aureofaciens (KaPOx) to form a functional monomer, and monomeric POx/CGOx from Streptomyces canus (ScPOx) to a dimeric structure. Deletion of the head and arm domains of the KaPOx subunit resulted in enzyme variants with a less hydrophobic surface, thus affecting its oligomerization. These monomeric KaPOx variants KaPOx_xal and KaPOx_xalh resembled monomeric wild-type POxs/CGOxs and preferred glycosides as substrates over monosaccharides with catalytic efficiencies for phlorizin being 24 × 106 higher compared to those for d-xylose. The wild-type dimeric KaPOx showed no activity towards glycosides. We hypothesize that KaPOx_xalh is unable to react with monosaccharides because the introduced mutations alter the positions of monosaccharide-binding residues. The inability of KaPOx to react with glycosides is likely caused by steric hindrance and the inaccessibility of the active site to bulky glycosides due to dimerization. The attempt to engineer ScPOx into a dimeric structure failed at the stage of soluble expression, likely due to exposed hydrophobic patches and aggregation.","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143367216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

RING dimerisation drives higher-order organisation of SINA/SIAH E3 ubiquitin ligases.

The FEBS journal Pub Date : 2025-02-05 DOI: 10.1111/febs.70000

Franck Coste, Aanchal Mishra, Catherine Chapuis, Lucija Mance, Zofia Pukało, Nicolas Bigot, Stéphane Goffinont, Virginie Gaudon, Norbert Garnier, Ibtissam Talhaoui, Bertrand Castaing, Sebastien Huet, Marcin J Suskiewicz

{"title":"RING dimerisation drives higher-order organisation of SINA/SIAH E3 ubiquitin ligases.","authors":"Franck Coste, Aanchal Mishra, Catherine Chapuis, Lucija Mance, Zofia Pukało, Nicolas Bigot, Stéphane Goffinont, Virginie Gaudon, Norbert Garnier, Ibtissam Talhaoui, Bertrand Castaing, Sebastien Huet, Marcin J Suskiewicz","doi":"10.1111/febs.70000","DOIUrl":"https://doi.org/10.1111/febs.70000","url":null,"abstract":"RING-type E3 ubiquitin ligases promote ubiquitylation by stabilising an active complex between a ubiquitin-loaded E2-conjugating enzyme and a protein substrate. To fulfil this function, the E3 ubiquitin-protein ligase SIAH1 and other SINA/SIAH subfamily RING-type E3 ligases employ an N-terminal catalytic RING domain and a C-terminal substrate-binding domain (SBD), separated by two zinc fingers. Here, we present the first crystal structure of the RING domain of human SIAH1, together with an adjacent zinc finger, revealing a potential RING dimer, which was validated in solution using static light scattering. RING dimerisation contributes to the E3 ligase activity of SIAH1 both in vitro and in cells. Moreover, as the RING domain is the second element, after the SBD, to independently favour homodimerisation within SINA/SIAH E3 ligases, we propose that alternating RING:RING and SBD:SBD interactions organise multiple copies of a SINA/SIAH protein into a higher-order homomultimer. In line with this hypothesis, fluorescently tagged full-length human SIAH1, human SIAH2 and fruit fly SINA show cytoplasmic clusters in human cells, whereas their distribution becomes more diffuse when RING dimerisation is disabled. The wild-type (WT) form of SIAH1, but not its RING dimerisation mutant, colocalises with aggregated synphilin-1A under proteasomal inhibition, suggesting that SIAH1 multimerisation might contribute to its reported preference for aggregated or multimeric substrates.","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143257669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Contact and communication: ZO-2 and the Hippo pathway.

The FEBS journal Pub Date : 2025-02-05 DOI: 10.1111/febs.17417

Miranda Thomas

引用次数: 0