The FEBS journal最新文献

{"title":"Hidden protein disorder: Deciphering the structural organisation and dynamics of a non-canonical CP12 from the diatom Thalassiosira pseudonana.","authors":"Alessio Bonucci, Tingting Wang, Hakima Baroudi, Emilien Etienne, Guillaume Gerbaud, Elisabetta Mileo, Goetz Parsiegla, Takahisa Yamato, Brigitte Gontero, Hélène Launay, Valérie Belle, Véronique Receveur-Bréchot","doi":"10.1111/febs.70187","DOIUrl":"https://doi.org/10.1111/febs.70187","url":null,"abstract":"<p><p>The chloroplastic protein CP12 from the diatom Thalassiosira pseudonana exhibits atypical and enigmatic structural properties that have so far hindered our understanding of its functions. Here, we used AlphaFold to generate a three-dimensional (3D) model of the structure of the protein. However, this model did not accurately describe the small-angle X-ray scattering (SAXS) data previously obtained. We have therefore undertaken a study using site-directed spin labelling combined with electron paramagnetic resonance (SDSL-EPR) to characterise the structural dynamics of this atypical CP12 and to investigate its dimeric organisation using double electron-electron resonance (DEER). We then performed molecular dynamics (MD) simulations, constrained by SAXS and DEER data, to refine the AlphaFold model and take into account the flexibility and disordered propensities of this protein. The combination of the experimental techniques together with the in silico AlphaFold and MD simulations reveals that the dimer is organised in an antiparallel arrangement of each monomer and that the C-terminal regions are highly flexible and partly disordered. Additionally, this diatom CP12 contains four structured domains likely to bind phosphoribulokinase regardless of their redox state. Our structural data therefore provide insights into the function of this protein in the regulation of the Calvin cycle and of photosynthesis in diatoms, whereas its structural organisation is completely different from any of its homologous counterparts from Plantae and cyanobacteria.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144661491","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}

{"title":"Enhancing macrophage phagocytosis of cancers by disrupting the SIRPα/CD47 signaling axis and targeting MUC1 antigen.","authors":"Saitong Muneekaew, Pasut Sasithong, Koollawat Chupradit, Kritayaporn Saiprayong, Thunchanok Nuchphongsai, Methichit Wattanapanitch","doi":"10.1111/febs.70192","DOIUrl":"https://doi.org/10.1111/febs.70192","url":null,"abstract":"<p><p>Signal regulatory protein alpha (SIRPα) is an essential immune checkpoint, predominantly expressed on myeloid cells, that binds to CD47. This interaction, termed the 'don't eat me' signal, contributes to immune suppression. Consequently, disruption of the SIRPα/CD47 axis emerges as a promising strategy to intervene in the 'don't eat me' signal, thereby initiating phagocytic activation. Various preclinical and clinical studies employed SIRPα/CD47-targeting molecules to disrupt the SIRPα/CD47 axis to promote cancer phagocytosis. However, concerns regarding their limited efficacy and side effects pose a challenge to applying this approach to cancer therapy. Here, we investigated the role of the SIRPα/CD47 axis in phagocytosis by performing clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-mediated SIRPA gene disruption in the monocytic cell line THP-1. The SIRPα knockout (KO) THP-1 cells were comprehensively characterized for their phenotype and functions, including differentiation into M0 macrophages, polarization into M1 or M2 macrophages, and phagocytosis of bioparticles and cancer cells, and compared to their wild-type (WT) counterparts. The SIRPα KO THP-1 cells retained their monocyte and macrophage characteristics. Remarkably, they exhibited enhanced phagocytosis of bioparticles and leukemic cell lines but not breast cancer cell lines. The introduction of a chimeric antigen receptor (CAR) targeting tumor-associated mucin1 antigen (tMUC1-CAR) further enhanced their phagocytic activity against the breast cancer cell line, MCF-7, which expresses high levels of MUC1. Our findings highlight the therapeutic potential of SIRPα KO macrophages in cancer immunotherapy, particularly for hematologic malignancies. However, a combination with CAR was necessary to enhance the phagocytic activity against solid cancer models.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144639172","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}

{"title":"Myopathy-linked mutations in TPM2 and their impact on troponin-mediated regulation of actomyosin contractility.","authors":"Recep Küçükdogru, Katarzyna Robaszkiewicz, Małgorzata Siatkowska, Peter Franz, Georgios Tsiavaliaris, Joanna Moraczewska","doi":"10.1111/febs.70180","DOIUrl":"https://doi.org/10.1111/febs.70180","url":null,"abstract":"<p><p>In striated muscle, the regulatory complex of tropomyosin (Tpm) and troponin (Tn) governs the Ca²⁺-dependent interactions between myosin heads and actin, controlling muscle contraction. The N-terminal and central regions of Tpm are crucial for Tn binding, yet their roles in regulating contraction in concert with Tn remain poorly understood. To explore this, we selected four pathogenic missense mutations in the TPM2 gene encoding the skeletal Tpm2.2 isoform (β-tropomyosin): D20H and E181K, associated with hypercontractility, and E41K and N202K, linked to hypocontractility. Using in vitro functional assays, we characterized these Tpm2.2 variants to unravel details of the molecular mechanisms underlying disease phenotypes. At low, non-activating Ca²⁺, all Tpm2.2 variants inhibited the Tn-regulated steady-state actomyosin ATPase reaction without affecting Tn binding to actin. At activating Ca²⁺, hypocontractile mutants suppressed actomyosin ATPase activity and motor function more than wild-type, suggesting interference with normal Tn regulation. Conversely, hypercontractile mutants enhanced myosin-driven actin translocation. Arrhenius plots revealed a limited ability of E181K mutant to activate Tn-regulated actomyosin ATPase at temperatures below 30 °C, which was fully recovered, and even enhanced, at physiological temperatures. In the absence of actin, the N-terminal mutations enhanced high-affinity Tpm2.2-Tn interactions, whereas central mutations had no effect. Additionally, although hypercontractile mutations increased Ca²⁺-sensitivity of the cross-bridge cycle, hypocontractile mutants decreased it. These findings demonstrate that mutations in the N-terminal and central segments of Tpm2.2 disrupt Tn-dependent regulation of actomyosin contractility through distinct mechanisms, providing new insights into the pathophysiology of Tpm-related myopathies.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144628456","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}

{"title":"Emerging roles for integrated stress response signaling in homeostasis","authors":"Shyama Nandakumar,&nbsp;Lydia Grmai,&nbsp;Deepika Vasudevan","doi":"10.1111/febs.70166","DOIUrl":"10.1111/febs.70166","url":null,"abstract":"<p>Across phyla, organisms have evolved signaling mechanisms to cope with cell-intrinsic and -extrinsic stressors. The integrated stress response (ISR) is a prime example of such a mechanism and has well-defined roles from yeast to humans in dealing with stress burdens imposed by nutrient deprivation, protein misfolding, infectious agents, and oxidative stress. As with many fundamental cellular processes, the complexity of ISR signaling increases with evolutionary complexity. While single-celled organisms have been reported to utilize ISR signaling in the context of stress, multicellular organisms also rely on ISR signaling components for a number of homeostatic functions. The role of ISR signaling in the absence of obvious stressors is less well-studied, though useful insights into this can be extrapolated from prior studies using loss-of-function mutants in model organisms. This review summarizes the known (and inferred) homeostatic roles for ISR signaling components and speculates on cellular functions and principles that might require stress-adaptive mechanisms such as ISR signaling to maintain homeostasis.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":"292 17","pages":"4418-4445"},"PeriodicalIF":4.2,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12276862/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144628455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overcoming BET-inhibitor JQ1 resistance in aggressive non-small cell lung cancer by inducing ferroptosis via inhibition of the BRD2-FTH1 axis.","authors":"Stefania Scicchitano, Cinzia Garofalo, Beatrice Stella, Gianluca Santamaria, Flora Cozzolino, Vittoria Monaco, Flavia Biamonte, Maria Monti, Eleonora Vecchio, Maria Concetta Faniello","doi":"10.1111/febs.70191","DOIUrl":"https://doi.org/10.1111/febs.70191","url":null,"abstract":"<p><p>Recent studies emphasize the involvement of the nuclear H ferritin subunit (FTH1; also known as ferritin heavy chain) in DNA protection from oxidative damage and transcriptional regulation. Bromodomain and extra-terminal domain (BET) proteins act as epigenome readers for transcriptional regulation. Among them, the role of bromodomain-containing protein 2 (BRD2) in non-small cell lung carcinoma (NSCLC) remains unclear. Moreover, the clinical utilization of BET bromodomain inhibition is severely limited by different sensitivities among NSCLC subtypes. This study provides the first evidence of nuclear BRD2-FTH1 functional interplay. Nuclear FTH1 is associated with BRD2, not bromodomain-containing protein 4 (BRD4), in a panel of NSCLC cell lines and affects BRD2 protein stability only in more aggressive types of NSCLC cells. In addition, the protective function of FTH1 was abrogated in FTH1-silenced cells that are resistant to synthetic BET bromodomain inhibitor JQ1 (a thieno-triazolo-1,4-diazepine) but not in JQ1-sensitive cells, leading to an increase in mortality. Then, the potential mechanism by which the combination of JQ1 with FTH1 silencing induces cell death was explored. The results show that ferroptosis is involved in the anticancer effect of JQ1 upon FTH1 silencing only in JQ1-insensitive cells. Moreover, the expression of ferroptosis-associated genes glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11 (SLC7A11) and solute carrier family 3 member 2 (SLC3A2) was downregulated under JQ1 treatment only after FTH1 silencing, indicating that the BRD2 inhibition due to the co-treatment could regulate the expression of ferroptosis-associated genes. In summary, for the first time, our data suggest that FTH1 silencing may serve as an effective anti-tumor strategy to enhance the activity of JQ1, acting to overcome the chemotherapy resistance in more aggressive NSCLCs.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144628457","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}

{"title":"A CRISPR-Cas9-based tool for dose-dependent DNA damage detection.","authors":"Valentyn Oksenych, Pavlo Petakh, Denis Kainov, Oleksandr Kamyshnyi","doi":"10.1111/febs.70186","DOIUrl":"https://doi.org/10.1111/febs.70186","url":null,"abstract":"<p><p>Auboiron et al. developed a CRISPR-Cas9-based system in yeast Saccharomyces cerevisiae that allows precise, dose-dependent induction of DNA double-strand breaks by targeting Ty retrotransposons. This system combines sequence specificity with control over break numbers (×1, ×15, or ×59), enabling a more detailed and precise study of DNA damage response. It revealed that the key DNA damage response kinase, Tel1, localizes to the nuclear periphery and forms multiple foci after induction of DNA double-strand breaks. The system also exposed limitations in Cas9 availability at higher break levels and offers a scalable platform for studying genome stability across organisms.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144628454","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}

{"title":"Ras pathways help buffer biological timekeeping against metabolic perturbations.","authors":"Patricia Lakin-Thomas","doi":"10.1111/febs.70188","DOIUrl":"https://doi.org/10.1111/febs.70188","url":null,"abstract":"<p><p>Circadian clocks need to be buffered against changes in conditions that could affect their rate and disrupt their timekeeping function. The circadian period of the fungus Neurospora is compensated across a range of nutritional conditions. Several gene products are implicated in the mechanism, but a complete picture is lacking. Sárkány et al. report that a Ras pathway linked to cAMP is required to maintain a constant period under low glucose conditions. They extend this work to a human cell line showing similar effects of the homologous Ras pathway, pointing toward potential conservation of compensation pathways across eukaryotes.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144628458","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}

{"title":"Melanoma cells suppress mast cell function via a melanin-dependent mechanism.","authors":"Fábio Rabelo Melo, Lea Nyman, Ida Österman Menander, Mirjana Grujic, Gunnar Pejler","doi":"10.1111/febs.70189","DOIUrl":"https://doi.org/10.1111/febs.70189","url":null,"abstract":"<p><p>Mast cells (MCs) have a well-established detrimental role in allergic conditions, but they can also impact diverse malignant conditions, including melanoma. To study the latter, previous studies have mainly evaluated how MCs can influence melanomas/melanoma cells. However, the inverse scenario, that is, whether melanoma/melanoma cells might impact MCs, has received less attention. Here we investigated this issue and show that melanoma cell-conditioned medium had a strong growth-inhibitory impact on MCs, which was attributed to inhibition of MC proliferation combined with induction of apoptosis. Further, our data indicate that such effects were attributable to melanin present in the melanoma cell-conditioned medium, as similar antiproliferative effects were seen in response to both free melanin and to melanocores enriched from melanoma cell-conditioned medium. Melanin did not reduce the expression of MC markers but was shown to impair MC activation. We also demonstrate that melanin is taken up by MCs, both in cultured MCs and in vivo in melanoma tumors, and it was observed that melanin, after uptake, can be found in the MC nucleus. Further, we show that melanin had marked effects on the nuclear morphology in MCs accompanied by clipping of core histone 3, and it is demonstrated that these events were dependent on translocation of tryptase, a granule-localized protease, into the MC nucleus. Tryptase was also shown to affect the mechanism of melanin-induced cell death. Altogether, the present study outlines a newly identified mechanism by which melanoma cells can suppress MC function, potentially representing an immunosuppressive mechanism that may influence tumor growth.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144612741","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}

{"title":"Production of functional human potassium channel protein K_V1.5 in an Escherichia coli-based cell-free protein synthesis system.","authors":"Zitong Zhao, Tianqi Zhou, Huizi Zhang, Yunyang Song, Fanghui Wu, Yifeng Yin, Yanli Liu","doi":"10.1111/febs.70190","DOIUrl":"https://doi.org/10.1111/febs.70190","url":null,"abstract":"<p><p>K_V1.5 is a member of the voltage-gated potassium ion channel family, which plays important roles in cell excitability, ion homeostasis and cell signaling. It is very difficult to rapidly obtain functional ion channel proteins in large quantities. Here, we report the utilisation of an Escherichia coli cell-free protein expression system to efficiently express K_V1.5 in a soluble form over a 16 h period, achieving a yield of up to 1 mg·mL^-1. The synthesised K_V1.5 was purified using a HisTrap HP column to capture the 6 × his tags in the presence of detergent FC-14. The resulting K_V1.5 exhibited α-helical secondary structures as assayed by circular dichroism spectroscopy, and demonstrated binding affinity for its agonist benzocaine through microscale thermophoresis measurements. Both, excitatory and inhibitory effects of benzocaine and vernakalant on reconstituted K_V1.5-liposomes was measured using H⁺-dependent quenching of a fluorescent dye, 9-amino-6-chloro-2-methoxyacridine, to monitor the flux of K⁺. Overall, our findings demonstrated that the functional human ion channel K_V1.5 could be heterologously synthesised via an E. coli-based cell-free protein expression system, which will expand the application scope of the cell-free protein expression system for structure and drug high-throughput screening within the entire voltage-gated potassium channel family.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144610828","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}

{"title":"High-throughput screening identifies a previously undescribed checkpoint controlling mitotic progression in response to DNA damage.","authors":"Nan Li, Rachel Gatenby, Thomas Walne, Caroline Daye, Steven Watson, Priya Lata, Stephen Brown, Ruth Thompson","doi":"10.1111/febs.70183","DOIUrl":"https://doi.org/10.1111/febs.70183","url":null,"abstract":"<p><p>Following DNA damage, the cell cycle can be slowed or halted to allow for DNA repair. However, the mechanisms underpinning mitotic delay in response to DNA damage are unclear. Through an unbiased high-throughput screen, here, we have identified superoxide dismutase 1 (SOD1) as an essential factor mediating mitotic delay in response to DNA damage. Cells with damaged DNA arrest at metaphase, indicating involvement of the spindle assembly checkpoint (SAC); however, this response is lost following SOD1 depletion. Furthermore, whilst depletion of SAC proteins promotes rapid cell division (often less than 10 min) in all conditions, SOD1 depletion has no impact on mitotic progression either in unperturbed mitosis or in response to spindle poisons and does not decrease the mitotic transit time beyond the normal rate. Cells depleted of SOD1 display damaged centromeres and mitotic defects but no longer exhibit DNA-damage-induced mitotic delay. SOD1 has previously been shown to mediate redox control of phosphatases such as PP2a. In response to DNA damage, we observed elevated phosphorylation of SAC protein BubR1 and the kinetochore protein KNL1. Dephosphorylation of these proteins is required for SAC silencing, and PP2a has previously been implicated in this. Following SOD1 depletion, we observed elevated PP2a activity and decreased phosphorylation of BubR1 and KNL1. We propose that, in response to damage, SOD1 restrains PP2a activity, resulting in elevated BubR1 and KNL1 phosphorylation leading to persistent SAC activation.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144610827","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}