The FEBS journal最新文献

{"title":"On the other side of the membrane: A new role for a luminal protein in the cytoplasm","authors":"Erik Snapp","doi":"10.1111/febs.70586","DOIUrl":"10.1111/febs.70586","url":null,"abstract":"<p>Proteins annotated as localizing inside membrane-bound organelles are accepted as residing there. Thus, encountering a mitochondrial cytochrome in the cytoplasm would be unexpected. Yet, a mitochondrial cytochrome does relocalize to the cytoplasm during apoptotic cell death. In fact, a growing list of annotated luminal proteins has demonstrable cytoplasmic functions. It is with this perspective of bi-compartmental proteins that I encourage you to read the new study from Zhu and Fu in this issue of <i>The FEBS Journal</i>. The authors investigate how stress inside the ER lumen influences cytoplasmic energy regulation and uncover a surprising mechanism in fission yeast.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":"293 20","pages":"6011-6015"},"PeriodicalIF":4.2,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147966339","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":"Unraveling the active site cover of coproheme decarboxylase from Listeria monocytogenes","authors":"Nikolaus Falb,&nbsp;Dominik Hörtnagel,&nbsp;Chris Oostenbrink,&nbsp;Paul G. Furtmüller,&nbsp;Stefan Hofbauer","doi":"10.1111/febs.70575","DOIUrl":"10.1111/febs.70575","url":null,"abstract":"<p>Coproheme decarboxylase (ChdC) is the terminal enzyme in Gram-positive heme <i>b</i> biosynthesis, an enzyme holding a special importance given its unique structure–function relationship and its necessity for bacterial survival. In the past, the enzyme has been shown to perform a double decarboxylation of two propionate groups on coproheme (Fe(III)-coproporphyrin III), subsequently converting it to heme <i>b</i> (iron-protoporphyrin IX). Notably, the active site of ChdCs is universally covered by a flexible loop. Its importance has not been fully studied but given its position it is assumed to provide steric hinderance for substrates or potential inhibitors to pass. This study aims to investigate its physiological role by introducing a histidine-to-alanine mutation located on the loop of ChdC from <i>Listeria monocytogenes</i>. Molecular dynamics simulation shows an increased flexibility of the structural element in the mutant. As a consequence, various kinetic studies at steady- and presteady-state conditions suggest coproheme binding and active site accessibility are improved. Using simulations and X-ray crystallography, we show evidence that the loop is originally stabilized by a hydrogen bond between S116 and the mutated H117. The higher accessibility also results in a higher susceptibility to damage from oxidative cosubstrates like H₂O₂, suggesting the loop in its wild-type conformation plays a key biological role in regulating the transfer of cosubstrates towards the main substrate coproheme.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":"293 20","pages":"6272-6288"},"PeriodicalIF":4.2,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/febs.70575","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147848218","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":"Neudesin modulates IGF1 and insulin signaling pathways by regulating the surface expression of IGF1R through a conserved WPE motif","authors":"Yoshiaki Nakayama,&nbsp;Motohiro Nonaka,&nbsp;Yuki Masuda,&nbsp;Hikaru Matsumoto,&nbsp;Katsuaki Higashi,&nbsp;Yangha Pak,&nbsp;Satsuki Komoda,&nbsp;Ayami Tagawa,&nbsp;Ryohei Shimizu,&nbsp;Tadahisa Mikami,&nbsp;Satomi Nadanaka,&nbsp;Toshihide Yamasaki,&nbsp;Kohei Sano,&nbsp;Takahiro Mukai,&nbsp;Hiroshi Kitagawa,&nbsp;Morichika Konishi","doi":"10.1111/febs.70566","DOIUrl":"10.1111/febs.70566","url":null,"abstract":"<p>Neudesin, a secreted protein implicated in diverse physiological processes, such as metabolism and immunity, lacks an identified receptor, which has prevented a detailed understanding of its molecular mechanisms. In this study, we aimed to elucidate the function of neudesin by identifying its cognate receptor and investigating its effects on cellular signaling. Using a combination of phage display, bioinformatics, and biochemical analysis, we identified insulin-like growth factor 1 receptor (IGF1R) as a high-affinity receptor for neudesin, with a binding affinity of 1.78 ± 1.87 n<span>m</span>. This interaction was mediated by a conserved tryptophan-proline-glutamic acid (WPE) motif in the IGF1R extracellular domain. Our cellular assays revealed that, while neudesin binding to IGF1R induces basal phosphorylation of the downstream signaling molecules extracellular signal-regulated kinase (ERK) and AKT (also known as Protein Kinase B, or PKB) in a cell-line-specific manner, it consistently acts as a negative modulator, attenuating both IGF1- and insulin-induced signaling. Mechanistically, neudesin promoted the downregulation of cell surface IGF1R, thereby reducing the receptor pool available for ligand stimulation. Furthermore, neudesin inhibited insulin signaling, likely through the co-internalization of IGF1R/insulin receptor (INSR) hybrid complexes. The physiological significance of this role was underscored in 3 T3-L1 adipocytes, where neudesin knockdown enhanced insulin-induced signaling and accelerated triglyceride accumulation. These results establish a novel molecular link between neudesin and the IGF1/insulin signaling axis, suggesting that neudesin may serve as an endogenous modulator of IGF1R/insulin activity, with potential implications for metabolic and growth-related diseases.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":"293 20","pages":"6193-6207"},"PeriodicalIF":4.2,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147793675","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":"Caffeylpyruvate hydrolase from the bioluminescent fungus Neonothopanus gardneri is the key recycling enzyme in the fungal bioluminescence pathway","authors":"Caio K. Zamuner,&nbsp;Douglas M. M. Soares,&nbsp;Bianca B. Nóbrega,&nbsp;Etelvino J. H. Bechara,&nbsp;Zinaida M. Kaskova,&nbsp;Alexander S. Mishin,&nbsp;Karen S. Sarkisyan,&nbsp;Ilia V. Yampolsky,&nbsp;Cassius V. Stevani","doi":"10.1111/febs.70554","DOIUrl":"10.1111/febs.70554","url":null,"abstract":"<p>Recent studies uncovered the fungal bioluminescence pathway (FBP), a biosynthetic signaling axis to which caffeic acid is central. A key step, the hydrolysis of oxyluciferin into caffeic and pyruvic acids, was previously observed only in crude extracts, with pyruvate formation uncertain. Using gene homology, we identified and cloned <i>cph</i> from <i>Neonothopanus gardneri</i>, encoding a predicted fumarylacetoacetate hydrolase (FAH)-family enzyme, named ngarCPH. We successfully expressed and purified ngarCPH and demonstrated its catalytic activity on oxyluciferin, confirming formation of both products. Kinetic characterization revealed the optimal temperature and pH, while structural modeling and multiple sequence alignment indicate characteristics similar to those of FAH enzymes. This work not only expands the knowledge of the function of enzymes from the FAH superfamily but also confirms a complete, self-sustained bioluminescence cycle in fungi. Our findings support the future development of autonomous bioluminescent systems in heterologous hosts.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":"293 20","pages":"6022-6037"},"PeriodicalIF":4.2,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/febs.70554","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147978375","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":"SHIP1 regulates TREM2 signalling and macrophage functions in a hiPSC-derived model.","authors":"Kim S Martin, Juliane Obst, Shania Ibarra, Emma J Murphy, Katerina O Gospodinova, Emma Mead","doi":"10.1111/febs.70752","DOIUrl":"https://doi.org/10.1111/febs.70752","url":null,"abstract":"<p><p>Genetic and functional studies strongly implicate microglia in the pathology of Alzheimer's disease. The Triggering Receptor Expressed on Myeloid cells 2 (TREM2) pathway is an important functional regulator of microglia, promoting phagocytosis of apoptotic cells, debris and pathogenic proteins. Genome-wide association studies have identified risk-bearing polymorphisms in several members of the pathway including INPP5D, encoding the inositol phosphatase SHIP1. Recent studies utilising in vitro and in vivo disease-relevant models have identified a role for SHIP1 in modulating TREM2 signalling and neurotoxic microglial activation. In this study, we characterised the role of SHIP1 in regulating TREM2 signalling and myeloid functions using human-induced pluripotent stem cell (hiPSC)-derived macrophages. Characterisation of isogenic SHIP1 knockout (SHIP1 KO) macrophages showed decreased expression of the lipopolysaccharide (LPS) coreceptor CD14, which translated to lower secretion of pro-inflammatory cytokines. Additionally, loss of SHIP1 in this macrophage model attenuated TREM2 signalling, which was further reflected in a reduced level of phagocytosis of apoptotic neurons compared to the parental line. The observed effects on TREM2 signalling did not correspond to changes in total protein levels or shedding. Further examination of macrophage scavenger receptor expression revealed reduced cell surface levels of CD163 and CD206 involved in resolution of inflammation, but increased levels of the phagocytic receptor MerTK. Morphological analysis revealed a less amoeboid-activated phenotype and increased adhesion in the SHIP1 KO macrophages. Taken together, our data indicate that SHIP1 plays a key role in modulating TREM2 signalling, inflammation and phagocytosis.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149186750","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":"Nutrient-specific combinatorial secretion of GLP-1 and neurotransmitters in the enteroendocrine L-cell line GLUTag.","authors":"Yo Ito, Kazuki Harada, Yuri Osuga-Yoshiike, Masami Yokota Hirai, Tetsuya Kitaguchi, Takashi Tsuboi","doi":"10.1111/febs.70753","DOIUrl":"https://doi.org/10.1111/febs.70753","url":null,"abstract":"<p><p>Enteroendocrine L cells function as chemosensors in the intestine, secreting glucagon-like peptide-1 (GLP-1) to signal nutrient ingestion to the brain. Since GLP-1 secretion is induced by a variety of nutrients, including sugars, amino acids, and fatty acids, GLP-1 receptor-expressing neurons are also activated regardless of the nutrient identity, making it unclear how the brain discriminates between different nutrients. By examining vesicle dynamics and extracellular signals associated with GLP-1, glutamate, and ATP in GLUTag cells using total internal reflection fluorescence (TIRF) microscopy, a technique that selectively visualizes fluorescent molecules near the plasma membrane, we demonstrated that distinct nutrients evoke specific secretory patterns. D-glucose induced the co-secretion of GLP-1, glutamate, and ATP, whereas L-glutamine induced the secretion of GLP-1 and glutamate but not ATP. Butyrate and sucralose, which are also GLP-1 secretagogues, did not induce the secretion of glutamate or ATP. While Ca²⁺ acts as the trigger for exocytosis, additional regulatory mechanisms are required to generate these distinct secretory patterns. We therefore investigated the cAMP and cGMP pathways and found that neither their activation nor inhibition detectably affected glutamate and ATP secretion, suggesting the involvement of other nutrient-specific signaling pathways. Collectively, our findings suggest that L cells distinguish and encode nutrient identity as combinatorial secretion patterns of GLP-1 and neurotransmitters.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149187273","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":"Toward understanding the catalytic mechanism for two classes of bacterial phospholipid N-methyltransferases","authors":"Irina Shevyreva,&nbsp;Lena Sophie Fritsch,&nbsp;Leander Mika Koch,&nbsp;Anton Effing,&nbsp;Meriyem Aktas,&nbsp;Franz Narberhaus","doi":"10.1111/febs.70571","DOIUrl":"10.1111/febs.70571","url":null,"abstract":"<p>Phosphatidylcholine (PC), the predominant phospholipid in eukaryotic membranes, also plays a crucial role in certain bacterial species, often mediating interactions with eukaryotic hosts. In bacteria, a major pathway for PC biosynthesis involves the three-step methylation of phosphatidylethanolamine, catalyzed by phospholipid <i>N</i>-methyltransferases (Pmts). While the binding site for the methyl donor <i>S</i>-adenosyl-<i><span>l</span></i>-methionine is well characterized in Pmt enzymes, the detailed mechanism of methyl group transfer remains poorly understood. In this study, we combined computational and biochemical approaches to identify the amino acid residues critical for the catalytic activity of two distinct Pmt classes: the <i>Rhodobacter</i> (<i>R</i>)-type enzyme from <i>Rubellimicrobium thermophilum</i> (<i>Rt</i>PmtA) and the <i>Sinorhizobium</i> (<i>S</i>)-type enzyme from <i>Agrobacterium tumefaciens</i> (<i>At</i>PmtA). Despite low sequence identity, both enzyme types share similar reaction mechanisms, with tyrosine residues playing key roles in methyl group transfer. In <i>Rt</i>PmtA, two highly conserved tyrosines located within the substrate-binding pocket on the N-terminal αA-helix are critical for enzymatic function. In contrast, <i>At</i>PmtA depends on a single tyrosine buried in the protein core for catalysis. These findings reveal distinct active site architectures and suggest that <i>R</i>-type and <i>S</i>-type enzymes have evolved class-specific structural strategies for tyrosine activation. This divergence highlights the evolutionary flexibility of Pmt enzymes, despite their shared catalytic function.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":"293 20","pages":"6253-6271"},"PeriodicalIF":4.2,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/febs.70571","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147825194","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":"Effects of GLP-1 agonists on the gut microbiota in type 2 diabetes mellitus: a systematic review","authors":"Ranicleide Santos Dantas,&nbsp;Lucas Vinícius Souza Santos,&nbsp;André Gustavo Carvalho de Oliveira,&nbsp;Marina dos Santos Barreto,&nbsp;Deise Maria Rego Rodrigues Silva,&nbsp;Pedro Henrique Macedo Moura,&nbsp;Eloia Emanuelly Dias Silva,&nbsp;Ronaldy Santana Santos,&nbsp;Lucas Alves da Mota Santana,&nbsp;Rajiv Gandhi Gopalsamy,&nbsp;Adriana Gibara Guimarães,&nbsp;Lysandro Pinto Borges","doi":"10.1111/febs.70656","DOIUrl":"10.1111/febs.70656","url":null,"abstract":"<p>Diabetes mellitus (DM) is a metabolic disease characterised by chronic hyperglycemia. The Glucagon-Like Peptide-1 Receptor Agonists (GLP-1 RAs) used in type 2 diabetes mellitus (T2DM) have been highlighted for their potential benefits to the gut microbiota in the context of this pathology. Therefore, it is important to investigate the relationship between microbiota and GLP-1 RAs used in T2DM. This review aimed at evaluating the effects of GLP-1 agonists on gut microbiota in T2DM individuals. The protocol was previously registered in PROSPERO, and the search was conducted in PubMed, Scopus, Web of Science, and Embase databases in March 2025. Two reviewers have read the titles and abstracts and selected the included articles based on established criteria. The initial search identified 5532 publications, of which 17 studies were included: 12 preclinical and 5 clinical. Most were conducted in China between 2016 and 2025. GLP-1 agonists have been shown to modulate the gut microbiota, characterised by an increase in Bacteroidetes, <i>Akkermansia muciniphila</i>, and <i>Lactobacillus</i>. These changes are accompanied by an improvement of intestinal villi, increase in occludin expression, as well as an improvement in colonic inflammation. We identified a higher abundance of bacterial species associated with intestinal balance (eubiosis), accompanied by reduced inflammation and insulin resistance. Conversely, there was a lower abundance of bacteria related to dysbiosis, such as <i>Firmicutes</i> and <i>Proteobacteria</i>, which can be unfavourable when in excess. GLP-1 agonists influence the intestinal microbiota, improving metabolic parameters and anti-inflammatory effects. However, further clinical studies are needed to corroborate the findings of this review.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":"293 20","pages":"5971-5995"},"PeriodicalIF":4.2,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/febs.70656","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148803957","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":"Unraveling in vitro phase separation and aggregation properties of the structured region of FMRP and the impact of Fragile X syndrome-linked mutations","authors":"Flavia Catalano,&nbsp;Alessandra Bigi,&nbsp;Francesca Troilo,&nbsp;Federica Gabriele,&nbsp;Gianluca Pistoia,&nbsp;Italia A. Asteriti,&nbsp;Francesco Angelucci,&nbsp;Giorgio Giardina,&nbsp;Fabrizio Chiti,&nbsp;Carlo Travaglini-Allocatelli,&nbsp;Adele Di Matteo","doi":"10.1111/febs.70564","DOIUrl":"10.1111/febs.70564","url":null,"abstract":"<p>Fragile X messenger ribonucleoprotein 1 (FMRP) is a multidomain RNA-binding protein highly expressed in neurons. It comprises a structured N-terminal region (NTR) containing five RNA/protein interaction domains and a large intrinsically disordered C-terminal region. A limited number of fragile X syndrome (FXS)-associated point mutations have been identified in the NTR, leading to the expression of mutated protein variants. Here, we show that the destabilizing effects of these mutations on the NTR region are less severe than those previously observed in the isolated domains, suggesting the presence of inter-domain interactions that stabilize the overall NTR architecture. Moreover, we demonstrate that the NTR structured region has an intrinsic propensity to undergo liquid–liquid phase separation (LLPS) and amyloid fibril formation <i>in vitro</i>, depending on protein concentration, and we characterize how three FXS-associated mutations (R138Q, G266E, and I304N) affect these processes. We show that the mutations either destabilize the entire NTR (G266E/I304N), markedly affect the kinetics of LLPS and suppress the droplet liquid nature (R138Q/G266E), or promote solid or gel-like non-amyloid aggregation (G266E), thus providing mechanistic insights into how they may alter protein function, contributing to the pathogenic mechanism. These findings suggest that the interplay between protein stability, LLPS, and fibrillization is finely regulated and may be critical for understanding FMRP function and its dysfunction in disease.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":"293 20","pages":"6155-6175"},"PeriodicalIF":4.2,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/febs.70564","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147825183","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":"Long-read sequencing-based atlas of tissue-specific expression of DNM1L transcript variants","authors":"Feng Yan,&nbsp;Jafar S. Jabbari,&nbsp;Naomi X. L. Ling,&nbsp;Anne M. Kong,&nbsp;Jia Q. Truong,&nbsp;Marnie L. Maddock,&nbsp;Ayeshah A. Rosdah,&nbsp;Christopher G. Langendorf,&nbsp;Lifang Zhang,&nbsp;Jarmon G. Lees,&nbsp;Sebastian Bass-Stringer,&nbsp;Danise Ann Onda,&nbsp;Alice Pébay,&nbsp;Mirella Dottori,&nbsp;Kim Loh,&nbsp;Jessica K. Holien,&nbsp;Sean Lal,&nbsp;Nadia M. Davidson,&nbsp;Jonathan S. Oakhill,&nbsp;Shiang Y. Lim","doi":"10.1111/febs.70568","DOIUrl":"10.1111/febs.70568","url":null,"abstract":"<p>Dynamin-related protein 1 (Drp1), encoded by <i>DNM1L</i>, is essential for mitochondrial fission, but its functional roles remain unclear due to isoform-specific effects from alternative splicing. Short-read RNA sequencing fails to resolve full-length isoforms involving distant exons, limiting our understanding. Here, we applied targeted long-read sequencing to profile full-length <i>DNM1L</i> transcripts in human left ventricle and induced pluripotent stem cell-derived cardiomyocytes, recovering all annotated isoforms with conserved expression patterns and isoforms 1–4 being the most abundant. Functional assays revealed that isoform abundance does not predict enzymatic activity. Extending this to six different mouse tissues, we identified distinct, tissue-enriched expression profiles. Functional rescue in Drp1-knockout mouse embryonic fibroblasts showed isoform-dependent differences in mitochondrial fission. Isoforms lacking the A-insert robustly rescued mitochondrial fission, with maximal activity observed for variants also lacking the B-insert (e.g. isoform b), consistent with a modulatory role of exon 3 in Drp1 activity. Our cross-species atlas integrates long-read transcriptomics with functional validation, revealing how isoform diversity underpins tissue-specific mitochondrial dynamics and physiological roles of Drp1.</p>","PeriodicalId":94226,"journal":{"name":"The FEBS journal","volume":"293 20","pages":"6208-6229"},"PeriodicalIF":4.2,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/febs.70568","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147793742","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}