bims-micesi 2025-02-23 papers

bims-micesi

Biomed News

on Mitotic cell signalling

Issue of 2025–02–23
fourteen papers selected by
Valentina Piano, Uniklinik Köln

An Aurora kinase A-BOD1L1-PP2A B56 axis promotes chromosome segregation fidelity.
SRBD1 facilitates chromosome segregation by promoting topoisomerase IIα localization to mitotic chromosomes.
Centromeres in the thermotolerant yeast K. marxianus mediate attachment to a single microtubule.
Evolutionary adaptation to hyperstable microtubules selectively targets tubulins and is empowered by the spindle assembly checkpoint.
Kinesin-like protein KIF18A is required for faithful coordination of chromosome congression with cytokinesis.
Haspin kinase binds to a nucleosomal DNA supergroove.
The MAST kinase KIN-4 carries out mitotic entry functions of Greatwall in C. elegans.
Dynamic R-loops at centromeres ensure chromosome alignment during oocyte meiotic divisions in mice.
Centromeres are stress-induced fragile sites.
Spatio-temporal control of mitosis using light via a Plk1 inhibitor caged for activity and cellular permeability.
Same but different: Centromere regulations in holocentric insects and plants.
The Depletion of TRAIP Results in the Retention of PCNA on Chromatin During Mitosis Leads to Inhibiting DNA Replication Initiation.
Mechanisms of PP2A-Ankle2 dependent nuclear reassembly after mitosis.
RNA methyltransferase SPOUT1/CENP-32 links mitotic spindle organization with the neurodevelopmental disorder SpADMiSS.

Cell Rep. 2025 Feb 18. pii: S2211-1247(25)00088-9. [Epub ahead of print]44(2): 115317

An Aurora kinase A-BOD1L1-PP2A B56 axis promotes chromosome segregation fidelity.

Thomas J Kucharski, Irma M Vlasac, Tatiana Lyalina, Martin R Higgs, Brock C Christensen, Susanne Bechstedt, Duane A Compton.

  Cancer cells are often aneuploid and frequently display elevated rates of chromosome mis-segregation, called chromosomal instability (CIN). CIN is caused by hyperstable kinetochore-microtubule (K-MT) attachments that reduce the correction efficiency of erroneous K-MT attachments. UMK57, a chemical agonist of the protein MCAK (mitotic centromere-associated kinesin), improves chromosome segregation fidelity in CIN cancer cells by destabilizing K-MT attachments, but cells rapidly develop resistance. To determine the mechanism, we performed unbiased screens, which revealed increased phosphorylation in cells adapted to UMK57 at Aurora kinase A phosphoacceptor sites on BOD1L1 (protein biorientation defective 1-like-1). BOD1L1 depletion or Aurora kinase A inhibition eliminated resistance to UMK57. BOD1L1 localizes to spindles/kinetochores during mitosis, interacts with the PP2A phosphatase, and regulates phosphorylation levels of kinetochore proteins, chromosome alignment, mitotic progression, and fidelity. Moreover, the BOD1L1 gene is mutated in a subset of human cancers, and BOD1L1 depletion reduces cell growth in combination with clinically relevant doses of Taxol or Aurora kinase A inhibitor.

Keywords:  Aurora; CP: Cancer; CP: Cell biology; kinase; kinetochore; microtubule; mitosis; phosphatase; phosphorylation; spindle

DOI:  https://doi.org/10.1016/j.celrep.2025.115317
Nat Commun. 2025 Feb 16. 16(1): 1675

SRBD1 facilitates chromosome segregation by promoting topoisomerase IIα localization to mitotic chromosomes.

Courtney A Lovejoy, Sarah R Wessel, Rahul Bhowmick, Yuki Hatoyama, Masato T Kanemaki, Runxiang Zhao, David Cortez.

Accurate sister chromatid segregation requires remodeling chromosome architecture, decatenation, and attachment to the mitotic spindle. Some of these events are initiated during S-phase, but they accelerate and conclude during mitosis. Here we describe SRBD1 as a histone and nucleic acid binding protein that prevents DNA damage in interphase cells, localizes to nascent DNA during replication and the chromosome scaffold in mitosis, and is required for chromosome segregation. SRBD1 inactivation causes micronuclei, chromatin bridges, and cell death. Inactivating SRBD1 immediately prior to mitotic entry causes anaphase failure, with a reduction in topoisomerase IIα localization to mitotic chromosomes and defects in properly condensing and decatenating chromosomes. In contrast, SRBD1 is not required to complete cell division after chromosomes are condensed. Strikingly, depleting condensin II reduces the severity of the anaphase defects in SRBD1-deficient cells by restoring topoisomerase IIα localization. Thus, SRBD1 is an essential genome maintenance protein required for mitotic chromosome organization and segregation.

DOI: https://doi.org/10.1038/s41467-025-56911-w
bioRxiv. 2025 Jan 27. pii: 2025.01.24.634737. [Epub ahead of print]

Centromeres in the thermotolerant yeast K. marxianus mediate attachment to a single microtubule.

Daniel J Barrero, Sabrine Hedouin, Yizi Mao, Charles L Asbury, Andrew Stergachis, Eileen O'Toole, Sue Biggins.

Eukaryotic chromosome segregation requires spindle microtubules to attach to chromosomes through kinetochores. The chromosomal locus that mediates kinetochore assembly is the centromere and is epigenetically specified in most organisms by a centromeric histone H3 variant called CENP-A. An exception to this is budding yeast which have short, sequenced-defined point centromeres. In S. cerevisiae , a single CENP-A nucleosome is formed at the centromere and is sufficient for kinetochore assembly. The thermophilic budding yeast Kluyveromyces marxianus also has a point centromere but its length is nearly double the S. cerevisiae centromere and the number of centromeric nucleosomes and kinetochore attachment sites is unknown. Purification of native kinetochores from K. marxianus yielded a mixed population, with one subpopulation that appeared to consist of doublets, making it unclear whether K. marxianus shares the same attachment architecture as S. cerevisiae. Here, we demonstrate that though the doublet kinetochores have a functional impact on kinetochore strength, kinetochore localization throughout the cell cycle appears conserved between these two yeasts. In addition, whole spindle electron tomography demonstrates that a single microtubule binds to each chromosome. Single-molecule nucleosome mapping analysis suggests the presence of a single centromeric nucleosome. Taken together, we propose that the K. marxianus point centromere assembles a single centromeric nucleosome that mediates attachment to one microtubule.

DOI: https://doi.org/10.1101/2025.01.24.634737
Cell Rep. 2025 Feb 15. pii: S2211-1247(25)00094-4. [Epub ahead of print]44(2): 115323

Evolutionary adaptation to hyperstable microtubules selectively targets tubulins and is empowered by the spindle assembly checkpoint.

Francesca Macaluso, Tasia Bos, Elena Chiroli, Paolo Bonaiuti, Jason C Apuan, Fridolin Gross, Simone Pompei, Luke M Rice, Andrea Ciliberto.

  Microtubules are polymers required for chromosome segregation. Their drug-induced hyperstabilization impairs chromosome segregation and is an established anti-cancer therapy. How cells respond to microtubule hyperstabilization, however, is incompletely understood. To study this, we evolved budding yeast cells expressing a microtubule-hyperstabilizing tubulin mutant and isolated adapted strains. Aneuploidy of specific chromosomes carrying the microtubule regulators STU2 and VIK1/KAR3 was the first observable adaptation. In the longer run, aneuploidies were outcompeted by mutations in α- or β-tubulin, partially overlapping with mutations in cancer patients. Thus, compensation of microtubule hyperstabilization follows a restrained and reproducible path where new mutations combine with the original offending mutation on the same carrier. While partly compensatory, several mutations failed to re-establish fully normal microtubule dynamics. Sustained growth relied on the mitotic checkpoint, indicating that extended mitotic timing limits the genomic instability caused by reduced microtubule dynamics. Our results predict a potential vulnerability of cells resistant to microtubule-hyperstabilizing agents.

Keywords:  CP: Cell biology; chromosome segregation; compensatory evolution; mitotic checkpoint; tubulin dynamics

DOI:  https://doi.org/10.1016/j.celrep.2025.115323
FEBS J. 2025 Feb 15.

Kinesin-like protein KIF18A is required for faithful coordination of chromosome congression with cytokinesis.

Su Hyun Lee, Mi-Sun Kwon, Taerim Lee, Sungchul Hohng, Hyunsook Lee.

  The maintenance of genetic integrity in proliferating cells requires the coordinated regulation of DNA replication, chromosome segregation, and cytokinetic abscission. Chromosome-microtubule interactions regulate mitosis, while interactions between the actin cytoskeleton and Myosin IIA dictate cytokinetic abscission. This process, crucial for the equal distribution of the duplicated genome into two daughter cells, occurs perpendicular to the axis of chromosome segregation. However, the mechanism of how microtubule-driven mitosis and actin-associated cytokinesis are precisely coordinated remains poorly understood. This study highlights the role of KIF18A, a kinesin-like protein, in linking kinetochore-microtubule dynamics to cytokinetic axis formation. KIF18A's localization changes through the cell division cycle, from the metaphase plate during chromosome congression to the central spindle in late anaphase, and finally to the spindle midbody in telophase. KIF18A depletion leads to chromosome congression failures and anaphase onset delays. Notably, cells attempting to undergo division in the absence of KIF18A exhibited disruptions in the parallel structure of the central spindle, causing mislocalization of the centralspindlin complex, such as kinesin-like protein KIF23 (also known as MKLP1) and Rac GTPase-activating protein 1 (RACGAP1). These disruptions impair cleavage furrow establishment, causing incomplete cytokinesis and the formation of mononuclear or binucleated cells. Our findings suggest that KIF18A is crucial for coordinating chromosome congression and cytokinesis by regulating the spatial and temporal assembly of the central spindle during late anaphase.

Keywords:  KIF18A; central spindle; centralspindlin; chromosome congression; cytokinesis

DOI:  https://doi.org/10.1111/febs.70019
Nat Struct Mol Biol. 2025 Feb 20.

Haspin kinase binds to a nucleosomal DNA supergroove.

Chad W Hicks, Colin R Gliech, Sanim Rahman, Xiangbin Zhang, Andrew S Eneim, Stacy J Vasquez, Andrew J Holland, Cynthia Wolberger.

Phosphorylation of histone H3 threonine 3 (H3T3) by Haspin recruits the chromosomal passenger complex to the inner centromere and ensures proper cell cycle progression through mitosis. The mechanism by which Haspin binds to nucleosomes to phosphorylate H3T3 is not known. Here we report cryogenic electron microscopy structures of the human Haspin kinase domain bound to a nucleosome. In contrast with previous structures of histone-modifying enzymes, Haspin solely contacts the nucleosomal DNA, inserting into a supergroove formed by apposing major grooves of two DNA gyres. This binding mode provides a plausible mechanism by which Haspin can bind to nucleosomes in a condensed chromatin environment to phosphorylate H3T3. We identify key basic residues in the Haspin kinase domain that are essential for phosphorylation of nucleosomal histone H3 and binding to mitotic chromatin. Our structural data provide notable insight into a histone-modifying enzyme that binds to nucleosomes solely through DNA contacts.

DOI: https://doi.org/10.1038/s41594-025-01502-y
EMBO J. 2025 Feb 17.

The MAST kinase KIN-4 carries out mitotic entry functions of Greatwall in C. elegans.

Ludivine Roumbo, Batool Ossareh-Nazari, Suzanne Vigneron, Ioanna Stefani, Lucie Van Hove, Véronique Legros, Guillaume Chevreux, Benjamin Lacroix, Anna Castro, Nicolas Joly, Thierry Lorca, Lionel Pintard.

  MAST-like, or Greatwall (Gwl), an atypical protein kinase related to the evolutionarily conserved MAST kinase family, is crucial for cell cycle control during mitotic entry. Mechanistically, Greatwall is activated by Cyclin B-Cdk1 phosphorylation of a 550 amino acids-long insertion in its atypical activation segment. Subsequently, Gwl phosphorylates Endosulfine and Arpp19 to convert them into inhibitors of PP2A-B55 phosphatase, thereby preventing early dephosphorylation of M-phase targets of Cyclin B-Cdk1. Here, searching for an elusive Gwl-like activity in C. elegans, we show that the single worm MAST kinase, KIN-4, fulfills this function in worms and can functionally replace Greatwall in the heterologous Xenopus system. Compared to Greatwall, the short activation segment of KIN-4 lacks a phosphorylation site, and KIN-4 is active even when produced in E. coli. We also show that a balance between Cyclin B-Cdk1 and PP2A-B55 activity, regulated by KIN-4, is essential to ensure asynchronous cell divisions in the early worm embryo. These findings resolve a long-standing puzzle related to the supposed absence of a Greatwall pathway in C. elegans, and highlight a novel aspect of PP2A-B55 regulation by MAST kinases.

Keywords:   C. elegans ; Development; Kinase; Mitosis; Phosphatase

DOI:  https://doi.org/10.1038/s44318-025-00364-w
Sci Bull (Beijing). 2025 Feb 13. pii: S2095-9273(25)00168-9. [Epub ahead of print]

Dynamic R-loops at centromeres ensure chromosome alignment during oocyte meiotic divisions in mice.

Yinghong Chen, Liying Wang, Qiuxing Zhou, Wei Wei, Huafang Wei, Yanjie Ma, Tingting Han, Shuang Ma, Xiaoming Huang, Meijia Zhang, Fei Gao, Chao Liu, Wei Li.

  R-loops play various roles in many physiological processes, however, their role in meiotic division remains largely unknown. Here we show that R-loops and their regulator RNase H1 are present at centromeres during oocyte meiotic divisions. Proper centromeric R-loops are essential to ensure chromosome alignment in oocytes during metaphase I (MI). Remarkably, both Rnaseh1 knockout and overexpression in oocytes lead to severe spindle assembly defects and chromosome misalignment due to dysregulation of R-loops at centromeres. Furthermore, we find that replication protein A (RPA) is recruited to centromeric R-loops, facilitating the deposition of ataxia telangiectasia-mutated and Rad3-related (ATR) kinase at centromeres by interacting with the ATR-interaction protein (ATRIP). The ATR kinase deposition triggers the activity of CHK1, stimulating the phosphorylation of Aurora B to finally promote proper spindle assembly and chromosome alignment at the equatorial plate. Most importantly, the application of ATR, CHK1, and Aurora B inhibitors could efficiently rescue the defects in spindle assembly and chromosome alignment due to RNase H1 deficiency in oocytes. Overall, our findings uncover a critical role of R-loops during mouse oocyte meiotic divisions, suggesting that dysregulation of R-loops may be associated with female infertility. Additionally, ATR, CHK1, and Aurora B inhibitors may potentially be used to treat some infertile patients.

Keywords:  Centromeres; Oocyte meiotic divisions; R-loops; RNase H1

DOI:  https://doi.org/10.1016/j.scib.2025.02.009
Curr Biol. 2025 Feb 14. pii: S0960-9822(25)00118-6. [Epub ahead of print]

Centromeres are stress-induced fragile sites.

Daniel Kolbin, Maëlle Locatelli, John Stanton, Katie Kesselman, Aryan Kokkanti, Jinghan Li, Elaine Yeh, Kerry Bloom.

  Centromeres are unique loci on eukaryotic chromosomes and are complexed with centromere-specific histone H3 molecules (CENP-A in mammals, Cse4 in yeast). The centromere provides the binding site for the kinetochore that captures microtubules and provides the mechanical linkage required for chromosome segregation. Centromeres encounter fluctuations in force as chromosomes jockey for position on the metaphase spindle. We have developed biological assays to examine the response of centromeres to high force. Torsional stress is induced on covalently closed DNA circles from supercoiling. Plasmid-borne centromeres with single-nucleotide inactivating mutations exhibit a high conversion frequency to plasmid dimer species. Conversion to dimers is dependent on the activity of the Rad1 single-strand endonuclease, indicative of unwinding a region of the centromere sequence in the absence of a functional kinetochore. To determine the region of unwinding, we used conditionally functional dicentric chromosomes to exert tension. Centromere DNA is exquisitely sensitive to cleavage following activation of the dicentric chromosome. Cleavage is dependent on the action of Rad1, highlighting the propensity of centromeres to unwind in response to supercoiling or mechanical stress. These studies provide mechanistic insights into the evolution of AT-rich pericentromere DNA throughout phylogeny and suggest a mechanism for stress-induced error correction at the centromere.

Keywords:  CENP-A nucleosome; DSB; Rad1 nuclease; centromere DNA; fragile sites; supercoiling tension

DOI:  https://doi.org/10.1016/j.cub.2025.01.055
Nat Commun. 2025 Feb 19. 16(1): 1599

Spatio-temporal control of mitosis using light via a Plk1 inhibitor caged for activity and cellular permeability.

Victoria von Glasenapp, Ana C Almeida, Dalu Chang, Ivana Gasic, Nicolas Winssinger, Monica Gotta.

The ability to control the activity of kinases spatially and temporally is essential to elucidate the role of signalling pathways in development and physiology. Progress in this direction has been hampered by the lack of tools to manipulate kinase activity in a highly controlled manner in vivo. Here we report a strategy to modify BI2536, the well characterized inhibitor of the conserved and essential mitotic kinase Polo-like kinase 1 (Plk1). We introduce the same coumarin photolabile protecting group (PPG) at two positions of the inhibitor. At one position, the coumarin prevents the interaction with Plk1, at the second it masks an added carboxylic acid, important for cellular retention. Exposure to light results in removal of both PPGs, leading to the activation of the inhibitor and its trapping inside cells. We demonstrate the efficacy of the caged inhibitor in three-dimensional spheroid cultures: by uncaging it with a single light pulse, we can inhibit Plk1 and arrest cell division, a highly dynamic process, with spatio-temporal control. Our design can be applied to other small molecules, providing a solution to control their activity in living cells with unprecedented precision.

DOI: https://doi.org/10.1038/s41467-025-56746-5
Curr Opin Cell Biol. 2025 Feb 20. pii: S0955-0674(25)00022-5. [Epub ahead of print]93 102484

Same but different: Centromere regulations in holocentric insects and plants.

André Marques, Ines A Drinnenberg.

Centromeres are essential chromosomal regions responsible for ensuring proper chromosome segregation during cell division. Unlike monocentric chromosomes, which have a single centromeric region, holocentric chromosomes distribute centromeric activity along their entire length. This unique organization poses intriguing questions about its structure, function, and evolutionary origins. In this review, we outline recent advances in characterizing the molecular architectures of holocentric chromosomes in mitosis and meiosis, emphasizing both the shared features and lineage-specific adaptations that have evolved in plants and insects. A more detailed characterization of holocentric architectures across different lineages will also offer valuable insights into the potential mechanisms driving the evolutionary transition from monocentric to holocentric chromosomes.

DOI: https://doi.org/10.1016/j.ceb.2025.102484
Genes Cells. 2025 Mar;30(2): e70006

The Depletion of TRAIP Results in the Retention of PCNA on Chromatin During Mitosis Leads to Inhibiting DNA Replication Initiation.

Yasushi Shiomi, Akiyo Hayashi, Yuichiro Saito, Masato T Kanemaki, Hideo Nishitani.

  Loading PCNA onto chromatin is a pivotal step in DNA replication, cell cycle progression, and genome integrity. Conversely, unloading PCNA from chromatin is equally crucial for maintaining genome stability. Cells deficient in the PCNA unloader ATAD5-RFC exhibit elevated levels of chromatin-bound PCNA during S phase, but still show dissociation of PCNA from chromatin in mitosis. In this study, we found that depletion of TRAIP, an E3 ubiquitin ligase, results in the retention of PCNA on chromatin during mitosis. Although TRAIP-depleted cells with chromatin-bound PCNA during mitosis progressed into the subsequent G1 phase, they displayed reduced levels of Cdt1, a key replication licensing factor, and impaired S phase entry. In addition, TRAIP-depleted cells exhibited delayed S phase progression. These results suggest that TRAIP functions independently of ATAD5-RFC in removing PCNA from chromatin. Furthermore, TRAIP appears to be essential for precise pre-replication complexes (pre-RCs) formation necessary for faithful initiation of DNA replication and S phase progression.

Keywords:  PCNA; TRAIP; cell cycle; replication initiation

DOI:  https://doi.org/10.1111/gtc.70006
Elife. 2025 Feb 18. pii: RP104233. [Epub ahead of print]13

Mechanisms of PP2A-Ankle2 dependent nuclear reassembly after mitosis.

Jingjing Li, Xinyue Wang, Laia Jordana, Éric Bonneil, Victoria Ginestet, Momina Ahmed, Mohammed Bourouh, Cristina Mirela Pascariu, T Martin Schmeing, Pierre Thibault, Vincent Archambault.

  In animals, mitosis involves the breakdown of the nucleus. The reassembly of a nucleus after mitosis requires the reformation of the nuclear envelope around a single mass of chromosomes. This process requires Ankle2 (also known as LEM4 in humans) which interacts with PP2A and promotes the function of the Barrier-to-Autointegration Factor (BAF). Upon dephosphorylation, BAF dimers cross-bridge chromosomes and bind lamins and transmembrane proteins of the reassembling nuclear envelope. How Ankle2 functions in mitosis is incompletely understood. Using a combination of approaches in Drosophila, along with structural modeling, we provide several lines of evidence that suggest that Ankle2 is a regulatory subunit of PP2A, explaining how it promotes BAF dephosphorylation. In addition, we discovered that Ankle2 interacts with the endoplasmic reticulum protein Vap33, which is required for Ankle2 localization at the reassembling nuclear envelope during telophase. We identified the interaction sites of PP2A and Vap33 on Ankle2. Through genetic rescue experiments, we show that the Ankle2/PP2A interaction is essential for the function of Ankle2 in nuclear reassembly and that the Ankle2/Vap33 interaction also promotes this process. Our study sheds light on the molecular mechanisms of post-mitotic nuclear reassembly and suggests that the endoplasmic reticulum is not merely a source of membranes in the process, but also provides localized enzymatic activity.

Keywords:  BAF; D. melanogaster; PP2A; ankle2; cell biology; mitosis; nuclear envelope; nucleus

DOI:  https://doi.org/10.7554/eLife.104233
Nat Commun. 2025 Feb 17. 16(1): 1703

RNA methyltransferase SPOUT1/CENP-32 links mitotic spindle organization with the neurodevelopmental disorder SpADMiSS.

Avinash V Dharmadhikari, Maria Alba Abad, Sheraz Khan, Reza Maroofian, Tristan T Sands, Farid Ullah, Itaru Samejima, Yanwen Shen, Martin A Wear, Kiara E Moore, Elena Kondakova, Natalia Mitina, Theres Schaub, Grace K Lee, Christine H Umandap, Sara M Berger, Alejandro D Iglesias, Bernt Popp, Rami Abou Jamra, Heinz Gabriel, Stefan Rentas, Alyssa L Rippert, Christopher Gray, Kosuke Izumi, Laura K Conlin, Daniel C Koboldt, Theresa Mihalic Mosher, Scott E Hickey, Dara V F Albert, Haley Norwood, Amy Feldman Lewanda, Hongzheng Dai, Pengfei Liu, Tadahiro Mitani, Dana Marafi, Hatice Koçak Eker, Davut Pehlivan, Jennifer E Posey, Natalie C Lippa, Natalie Vena, Erin L Heinzen, David B Goldstein, Cyril Mignot, Jean-Madeleine de Sainte Agathe, Nouriya Abbas Al-Sannaa, Mina Zamani, Saeid Sadeghian, Reza Azizimalamiri, Tahere Seifia, Maha S Zaki, Ghada M H Abdel-Salam, Mohamed S Abdel-Hamid, Lama Alabdi, Fowzan Sami Alkuraya, Heba Dawoud, Aya Lofty, Peter Bauer, Giovanni Zifarelli, Erum Afzal, Faisal Zafar, Stephanie Efthymiou, Daniel Gossett, Meghan C Towne, Raey Yeneabat, Belen Perez-Duenas, Ana Cazurro-Gutierrez, Edgard Verdura, Veronica Cantarin-Extremera, Ana do Vale Marques, Aleksandra Helwak, David Tollervey, Sandeep N Wontakal, Vimla S Aggarwal, Jill A Rosenfeld, Victor Tarabykin, Shinya Ohta, James R Lupski, Henry Houlden, William C Earnshaw, Erica E Davis, A Arockia Jeyaprakash, Jun Liao.

SPOUT1/CENP-32 encodes a putative SPOUT RNA methyltransferase previously identified as a mitotic chromosome associated protein. SPOUT1/CENP-32 depletion leads to centrosome detachment from the spindle poles and chromosome misalignment. Aided by gene matching platforms, here we identify 28 individuals with neurodevelopmental delays from 21 families with bi-allelic variants in SPOUT1/CENP-32 detected by exome/genome sequencing. Zebrafish spout1/cenp-32 mutants show reduction in larval head size with concomitant apoptosis likely associated with altered cell cycle progression. In vivo complementation assays in zebrafish indicate that SPOUT1/CENP-32 missense variants identified in humans are pathogenic. Crystal structure analysis of SPOUT1/CENP-32 reveals that most disease-associated missense variants are located within the catalytic domain. Additionally, SPOUT1/CENP-32 recurrent missense variants show reduced methyltransferase activity in vitro and compromised centrosome tethering to the spindle poles in human cells. Thus, SPOUT1/CENP-32 pathogenic variants cause an autosomal recessive neurodevelopmental disorder: SpADMiSS (SPOUT1 Associated Development delay Microcephaly Seizures Short stature) underpinned by mitotic spindle organization defects and consequent chromosome segregation errors.

DOI: https://doi.org/10.1038/s41467-025-56876-w