Affinage

DSN1

Kinetochore-associated protein DSN1 homolog · UniProt Q9H410

Round 2 corrected
Length
356 aa
Mass
40.1 kDa
Annotated
2026-04-28
41 papers in source corpus 18 papers cited in narrative 18 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

DSN1 is a core subunit of the conserved four-subunit MIS12 complex (MIS12–PMF1–NSL1–DSN1) that serves as the central bridge between inner kinetochore receptors (CENP-C and CENP-T) and the outer kinetochore microtubule-binding complexes NDC80 and KNL1, and is therefore essential for chromosome segregation during mitosis (PMID:15371340, PMID:16585270, PMID:20819937). Crystal and cryo-EM structures show that the DSN1 N-terminal auto-inhibitory segment occludes CENP-C and CENP-T binding sites on the MIS12 complex; Aurora B phosphorylation of DSN1 Ser100/Ser109 releases this auto-inhibition, acting as a phospho-switch that controls kinetochore assembly (PMID:27881301, PMID:39178843). Protein levels of DSN1 are regulated by Mub1/Ubr2-mediated ubiquitylation in yeast as a quality-control mechanism, and its mRNA is stabilized by the m6A reader SRSF9 in human colorectal cancer cells (PMID:23408894, PMID:35509101). A germline-specific splice isoform that lacks the Aurora B-regulated N-terminal domain enables constitutive centromere localization and is required for oocyte maturation and early embryonic divisions in mice (PMID:39178843).

Mechanistic history

Synthesis pass · year-by-year structured walk · 9 steps
  1. 2004 High

    Identification of DSN1 as a conserved outer kinetochore component resolved the molecular composition of the KMN network and established that loss of DSN1 abolishes kinetochore assembly and chromosome segregation.

    Evidence Co-purification from C. elegans embryos with RNAi phenotyping, and tandem-affinity purification of the human hMis12 complex with RNAi in HeLa cells

    PMID:15371340 PMID:15502821

    Open questions at the time
    • Precise stoichiometry of DSN1 within the complex was unresolved
    • No structural information on DSN1 or its interaction interfaces
  2. 2006 High

    Reconstitution of the four-subunit MIS12 complex and demonstration that its depletion eliminates NDC80/HEC1 kinetochore recruitment established DSN1 as essential for outer kinetochore assembly in vertebrate cells.

    Evidence Bacterial coexpression of the four-subunit complex, mitotic extract fractionation, RNAi in HeLa and DT40 cells

    PMID:16585270

    Open questions at the time
    • Which subunit directly contacts NDC80 and KNL1 was unknown
    • Regulation of DSN1 during the cell cycle was uncharacterized
  3. 2010 High

    Structural visualization of the elongated MIS12 complex by negative-stain EM and mapping of DSN1's position within the complex head defined the architecture that mediates bridging between KNL1/NDC80 and the inner kinetochore.

    Evidence Negative-stain EM, chemical cross-linking, and pulldown assays with recombinant MIS12 complex

    PMID:20819937

    Open questions at the time
    • Atomic-resolution structure of DSN1 was still lacking
    • How DSN1 phosphorylation controls binding was unknown
  4. 2013 High

    Two parallel studies revealed that CENP-T binds the MIS12 complex independently of CENP-C, defining dual pathways for NDC80 recruitment, and that Dsn1 protein levels are controlled by Mub1/Ubr2-mediated ubiquitylation as a kinetochore quality-control mechanism.

    Evidence Structural and biochemical reconstitution of CENP-T–MIS12C interaction in DT40 cells; kinetochore particle purification, genetic epistasis, and ubiquitylation assays in S. cerevisiae

    PMID:23334297 PMID:23408894

    Open questions at the time
    • The structural basis of DSN1's contacts with CENP-C and CENP-T was unresolved
    • Whether ubiquitin-mediated regulation of DSN1 is conserved in mammals was untested
  5. 2016 High

    Crystal structures of the MIS12 complex bound to CENP-C revealed that Aurora B phosphorylation of DSN1 Ser100/Ser109 releases an N-terminal auto-inhibitory segment that competes with CENP-C binding, establishing the phospho-regulatory switch governing inner–outer kinetochore coupling.

    Evidence X-ray crystallography of MIS12C:CENP-C complex, phosphomimetic/phosphodead mutagenesis, Aurora B kinase assays

    PMID:27881301

    Open questions at the time
    • Whether the same switch controls CENP-T binding was unclear
    • The structural basis of auto-inhibition at atomic resolution in the context of the full KMN was unresolved
  6. 2022 Medium

    Post-transcriptional regulation of DSN1 was revealed: SRSF9 functions as an m6A reader that stabilizes DSN1 mRNA via METTL3-deposited m6A marks, linking epitranscriptomic regulation to DSN1 protein abundance in colorectal cancer.

    Evidence Methylated RNA affinity assay, gene-specific m6A qRT-PCR, RNA stability assays, and xenograft models in CRC cells

    PMID:35509101

    Open questions at the time
    • Whether m6A-mediated DSN1 regulation occurs in normal (non-cancer) cells is unknown
    • The specific m6A writer–reader axis for DSN1 in other tissue contexts is uncharacterized
  7. 2024 High

    Discovery of a germline-specific DSN1 splice isoform that lacks the Aurora B-regulated N-terminal domain showed that germ cells bypass mitotic phospho-regulation to achieve constitutive kinetochore assembly, and that this isoform is required for oocyte maturation and fertility.

    Evidence Isoform cloning, CRISPR mouse models with isoform-specific deletion, live-cell imaging of oocytes, Aurora kinase inhibitor experiments

    PMID:39178843

    Open questions at the time
    • Whether the germline isoform is conserved in non-mammalian vertebrates is untested
    • How meiotic chromosome segregation fidelity is maintained without the auto-inhibitory regulatory step is unclear
  8. 2025 High

    Cryo-EM structures of the budding yeast KMN complex provided atomic detail of the DSN1 auto-inhibitory helices engaging its head domain and the C-terminal helical motifs mediating KNL1 and NDC80 binding, unifying genetic and biochemical data into a complete structural framework.

    Evidence Cryo-EM structure determination with biochemical and genetic validation in S. cerevisiae (preprint)

    PMID:bio_10.1101_2025.06.03.657598

    Open questions at the time
    • Full-length human KMN cryo-EM structure is still unavailable
    • Dynamics of auto-inhibition release in vivo are unresolved
  9. 2026 Medium

    A non-canonical cancer-associated function was identified: DSN1 stabilizes c-MYC by competing with the FZR1 E3 ligase for c-MYC binding, thereby attenuating ubiquitin-mediated c-MYC degradation and promoting colorectal cancer metastasis.

    Evidence Cycloheximide chase, co-IP competition between DSN1 and FZR1 for c-MYC, siRNA knockdown with c-MYC rescue, in vivo metastasis model

    PMID:41713835

    Open questions at the time
    • Whether DSN1–c-MYC interaction occurs in normal proliferating cells is unknown
    • The structural basis of DSN1–c-MYC binding and FZR1 competition is uncharacterized
    • Independent replication in other cancer types is lacking

Open questions

Synthesis pass · forward-looking unresolved questions
  • Key unresolved questions include the full atomic structure of the human KMN super-complex in the kinetochore context, whether ubiquitin-mediated DSN1 quality control (Mub1/Ubr2) is conserved in mammals, and how the germline DSN1 isoform maintains segregation fidelity without Aurora B-dependent regulation.
  • No human KMN cryo-EM structure available
  • Mammalian DSN1 ubiquitylation pathway not characterized
  • Germline isoform segregation fidelity mechanism unknown

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0005198 structural molecule activity 5 GO:0060090 molecular adaptor activity 3
Localization
GO:0005694 chromosome 6 GO:0005634 nucleus 2
Pathway
R-HSA-1640170 Cell Cycle 5
Partners
CENP-CCENP-TKNL1MIS12NDC80NSL1PMF1
Complex memberships
KMN networkMIS12 complex

Evidence

Reading pass · 18 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2004 DSN1 (KNL3 in C. elegans) was identified as a subunit of a conserved outer kinetochore protein network (KMN). Depletion of the C. elegans ortholog (KNL-3) caused a 'kinetochore null' phenotype, abolishing kinetochore assembly and chromosome segregation, placing DSN1 as a core component of the MIS/KMN outer kinetochore module. Protein co-purification from C. elegans embryos, RNAi depletion with live-imaging phenotypic readout, homolog identification in human cells Genes & development High 15371340
2004 Human DSN1 (c20orf172) was identified as a subunit of the conserved hMis12 core complex. The complex also contained hNnf1(PMF1), hNsl1(DC8), and hMis12, and interacted with centromeric heterochromatin components HP1α and HP1γ; RNAi of any subunit disrupted chromosome segregation in HeLa cells. Tandem-affinity purification of hMis12 complex, RNAi knockdown, immunofluorescence localization in HeLa cells Nature cell biology High 15502821
2006 Human DSN1 (hDsn1/Q9H410), together with hNnf1(PMF1) and hNsl1(DC31), forms a stable four-subunit complex with hMis12 demonstrable by coexpression in bacteria and fractionation of mitotic extracts. Depletion of any Mis12 complex subunit caused mitotic delay, chromosome misalignment, reduced centromere stretch, and severely diminished outer kinetochore protein Ndc80/HEC1 localization, establishing the Mis12 complex as essential for outer kinetochore assembly. Bacterial coexpression, mitotic extract fractionation, RNAi depletion in human and chicken DT40 cells, immunofluorescence The Journal of cell biology High 16585270
2006 DSN1 was detected as a phosphorylated protein in purified human mitotic spindles, identifying it as a substrate of mitotic phosphorylation events. Mass spectrometry-based phosphoproteomics of purified human mitotic spindles Proceedings of the National Academy of Sciences of the United States of America Medium 16565220
2007 DSN1-containing hMis12 complex subunits (c20orf172/hMis13 and DC8/hMis14) were shown to associate with the C-terminal domain of blinkin (KNL1/AF15q14), placing DSN1 at the interface between the inner kinetochore and the KNL1 scaffold that recruits spindle-checkpoint proteins Bub1 and BubR1. Co-immunoprecipitation, domain-mapping pulldown assays, RNAi in HeLa cells Developmental cell Medium 17981135
2010 Biochemical analysis and negative-stain electron microscopy of the human MIS12 complex revealed an elongated ~22 nm structure. NSL1 (not DSN1) acts as the scaffold, but DSN1 occupies a defined position in the complex head and makes contacts required for interaction with the NDC80 and KNL1 complexes within the KMN network. Biochemical fractionation, chemical cross-linking, negative-stain electron microscopy, pulldown assays The Journal of cell biology High 20819937
2010 High-throughput tandem-affinity purification and mass spectrometry (MitoCheck) confirmed DSN1 as a stable component of the human Mis12 complex and localized it to kinetochores during mitosis. BAC-based gene tagging, TAP-MS, immunofluorescence localization Science Medium 20360068
2013 In budding yeast, the Mub1/Ubr2 ubiquitin ligase complex associates with kinetochore particles via CENP-C (Mif2) and ubiquitylates Dsn1 to regulate its protein levels. Deletion of Mub1/Ubr2 restores levels and viability of a mutant Dsn1, suggesting Mub1/Ubr2 act as a quality control system that degrades aberrant Dsn1 to maintain kinetochore integrity. Kinetochore particle purification, co-immunoprecipitation, genetic deletion analysis, ubiquitylation assay, viability rescue experiments in S. cerevisiae PLoS genetics High 23408894
2013 CENP-T interacts with the Mis12 complex (containing DSN1) and with the Ndc80 complex via mutually exclusive binding; CENP-T and Mis12C compete for Ndc80 binding, defining two distinct pathways that independently recruit the Ndc80 complex to kinetochores. Structural analysis, biochemical reconstitution, pulldown competition assays, DT40 cell depletion experiments The EMBO journal High 23334297
2016 Crystal structures of the human MIS12 complex (containing DSN1) bound to a CENP-C fragment revealed the structural basis of MIS12C's bridging function between the outer kinetochore (KMN) and inner kinetochore. Aurora B kinase phosphorylation of the DSN1 N-terminal region (specifically Ser100 and Ser109) releases auto-inhibition and dramatically strengthens CENP-C binding, revealing a phospho-regulatory switch controlling kinetochore assembly. X-ray crystallography of MIS12C:CENP-C complex, biochemical binding assays with phosphomimetic/phosphodead mutants, Aurora B kinase assay Cell High 27881301
2016 DSN1 protein levels were sequentially up-regulated during colorectal adenoma-to-carcinoma progression; DSN1 knockdown in CRC cells induced G2/M arrest and decreased migration, invasion, and anchorage-independent growth, implicating DSN1 in chromosome 20q amplification-associated malignant transformation. SNP genotyping, RNA sequencing of patient tri-part samples, siRNA knockdown, cell growth/apoptosis/migration/invasion assays Oncotarget Medium 27329586
2021 ESRRA was shown to transcriptionally regulate DSN1 expression in gastric cancer. ChIP and dual-luciferase assays confirmed ESRRA directly binds the DSN1 promoter. ESRRA silencing caused G2/M arrest via the CDC25C–CDK1–Cyclin B1 pathway downstream of DSN1 reduction, placing DSN1 in an ESRRA→DSN1→CDC25C/CDK1/CyclinB1 signaling axis. RNA-seq, ChIP assay, dual-luciferase reporter assay, Western blot, flow cytometry (cell cycle), siRNA knockdown International journal of biological sciences Medium 34131395
2022 SRSF9 stabilizes DSN1 mRNA in an m6A-dependent manner in colorectal cancer cells. SRSF9 acts as an m6A reader, binding to two m6A modification sites in the DSN1 mRNA 3′ region; METTL3 knockdown impaired both SRSF9 binding and DSN1 mRNA stabilization. DSN1 knockdown partially reversed SRSF9 overexpression-induced CRC cell phenotypes. Methylated RNA affinity assay, gene-specific m6A qRT-PCR, dual-luciferase reporter, RNA stability assay, siRNA knockdown, xenograft model Journal of translational medicine Medium 35509101
2024 Mammalian germ cells express a germline-specific alternative splice isoform of DSN1 that lacks a key N-terminal regulatory region required for Aurora kinase phosphorylation-dependent centromere localization. This isoform displays constitutive centromere localization independent of Aurora B phosphorylation. Expression of the germline isoform in somatic cells causes constitutive kinetochore localization, chromosome segregation errors, and growth defects. Selective elimination of the germline isoform in mouse models disrupts oocyte maturation and early embryonic divisions, reducing fertility. Alternative splice isoform cloning, immunofluorescence in oocytes and somatic cells, Aurora kinase inhibitor treatment, CRISPR mouse models with isoform-specific deletion, live-cell imaging, fertility assays Current biology : CB High 39178843
2024 DSN1 directly interacts with Centromere Protein T (CENP-T) in hepatocellular carcinoma cells; elevated DSN1 expression led to overproduction of cell cycle-related proteins through this interaction, contributing to chromosomal instability and aberrant cell cycle progression. siRNA/shRNA knockdown of DSN1 reduced xenograft tumor growth. Co-immunoprecipitation, siRNA/shRNA knockdown, overexpression vectors, xenograft tumor model, TCGA database analysis Molecular carcinogenesis Medium 39560395
2024 AlphaFold2-based predictions and cell biological experiments in chicken DT40 cells identified two binding surfaces for the CENP-T–Mis12C (DSN1-containing) interaction. Dual phosphorylation of Dsn1 and CENP-T cooperatively regulates this interaction to ensure robust CENP-T–Mis12C binding and proper mitotic progression. AlphaFold2 structure prediction, mutagenesis of binding surfaces, DT40 cell conditional depletion, co-immunoprecipitation, cell viability assays bioRxivpreprint Medium bio_10.1101_2024.06.20.599825
2025 Cryo-EM structures of the budding yeast KMN complex revealed that the N-terminal auto-inhibitory segment of Dsn1 (Dsn1-AI) folds into two α-helices that engage its head domain, occluding binding sites for inner kinetochore subunits CENP-C (Mif2) and CENP-U (Ame1). Aurora B (Ipl1) phosphorylation of Dsn1-AI releases this auto-inhibition to strengthen inner–outer kinetochore connections. C-terminal α-helical motifs of Dsn1 and other Mis12c subunits mediate binding to Knl1c and Ndc80c. Cryo-EM structure determination, biochemical binding assays, genetic experiments in S. cerevisiae bioRxivpreprint High bio_10.1101_2025.06.03.657598
2026 DSN1 stabilizes c-MYC protein in colorectal cancer by competing with the E3 ubiquitin ligase FZR1 for c-MYC binding, thereby attenuating FZR1-mediated ubiquitination and proteasomal degradation of c-MYC. DSN1 knockdown accelerated c-MYC degradation and reduced CRC invasion/metastasis in vitro and in vivo; c-MYC overexpression rescued the anti-metastatic effect of DSN1 silencing. Cycloheximide chase assay, proteasome inhibitor assay, co-immunoprecipitation (DSN1–FZR1, FZR1–c-MYC competition), siRNA knockdown, rescue overexpression, in vivo metastasis model Experimental cell research Medium 41713835

Source papers

Stage 0 corpus · 41 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2006 Global, in vivo, and site-specific phosphorylation dynamics in signaling networks. Cell 2861 17081983
2012 Insights into RNA biology from an atlas of mammalian mRNA-binding proteins. Cell 1718 22658674
2002 Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences. Proceedings of the National Academy of Sciences of the United States of America 1479 12477932
2015 The BioPlex Network: A Systematic Exploration of the Human Interactome. Cell 1118 26186194
2017 Architecture of the human interactome defines protein communities and disease networks. Nature 1085 28514442
2015 A human interactome in three quantitative dimensions organized by stoichiometries and abundances. Cell 1015 26496610
2020 A reference map of the human binary protein interactome. Nature 849 32296183
2003 Complete sequencing and characterization of 21,243 full-length human cDNAs. Nature genetics 754 14702039
2008 Molecular architecture of the kinetochore-microtubule interface. Nature reviews. Molecular cell biology 753 18097444
2021 Dual proteome-scale networks reveal cell-specific remodeling of the human interactome. Cell 705 33961781
2011 Phylogenetic-based propagation of functional annotations within the Gene Ontology consortium. Briefings in bioinformatics 656 21873635
2004 The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). Genome research 438 15489334
2022 OpenCell: Endogenous tagging for the cartography of human cellular organization. Science (New York, N.Y.) 432 35271311
2010 Systematic analysis of human protein complexes identifies chromosome segregation proteins. Science (New York, N.Y.) 421 20360068
2018 DNA Repair Network Analysis Reveals Shieldin as a Key Regulator of NHEJ and PARP Inhibitor Sensitivity. Cell 379 29656893
2004 A conserved protein network controls assembly of the outer kinetochore and its ability to sustain tension. Genes & development 356 15371340
2021 A proximity-dependent biotinylation map of a human cell. Nature 339 34079125
2006 Phosphoproteome analysis of the human mitotic spindle. Proceedings of the National Academy of Sciences of the United States of America 281 16565220
2011 A directed protein interaction network for investigating intracellular signal transduction. Science signaling 258 21900206
2007 Human Blinkin/AF15q14 is required for chromosome alignment and the mitotic checkpoint through direct interaction with Bub1 and BubR1. Developmental cell 249 17981135
2007 hORFeome v3.1: a resource of human open reading frames representing over 10,000 human genes. Genomics 222 17207965
2004 A conserved Mis12 centromere complex is linked to heterochromatic HP1 and outer kinetochore protein Zwint-1. Nature cell biology 222 15502821
2010 Human POGZ modulates dissociation of HP1alpha from mitotic chromosome arms through Aurora B activation. Nature cell biology 217 20562864
2016 A High-Density Map for Navigating the Human Polycomb Complexome. Cell reports 216 27705803
2005 ZW10 links mitotic checkpoint signaling to the structural kinetochore. The Journal of cell biology 214 15824131
2010 The MIS12 complex is a protein interaction hub for outer kinetochore assembly. The Journal of cell biology 190 20819937
2006 The human Mis12 complex is required for kinetochore assembly and proper chromosome segregation. The Journal of cell biology 178 16585270
2013 CENP-T provides a structural platform for outer kinetochore assembly. The EMBO journal 170 23334297
2001 The DNA sequence and comparative analysis of human chromosome 20. Nature 168 11780052
2016 Structure of the MIS12 Complex and Molecular Basis of Its Interaction with CENP-C at Human Kinetochores. Cell 132 27881301
2016 Over-expression of AURKA, SKA3 and DSN1 contributes to colorectal adenoma to carcinoma progression. Oncotarget 68 27329586
2021 ESRRA promotes gastric cancer development by regulating the CDC25C/CDK1/CyclinB1 pathway via DSN1. International journal of biological sciences 42 34131395
2022 SRSF9 promotes colorectal cancer progression via stabilizing DSN1 mRNA in an m6A-related manner. Journal of translational medicine 36 35509101
2013 The Mub1/Ubr2 ubiquitin ligase complex regulates the conserved Dsn1 kinetochore protein. PLoS genetics 24 23408894
2020 Identification of CDCA8, DSN1 and BIRC5 in Regulating Cell Cycle and Apoptosis in Osteosarcoma Using Bioinformatics and Cell Biology. Technology in cancer research & treatment 17 33153400
2009 Searching for Drosophila Dsn1 kinetochore protein. Cell cycle (Georgetown, Tex.) 14 19270503
2024 A conserved germline-specific Dsn1 alternative splice isoform supports oocyte and embryo development. Current biology : CB 10 39178843
2024 A conserved germline-specific Dsn1 alternative splice isoform supports oocyte and embryo development. bioRxiv : the preprint server for biology 1 38659852
2026 DSN1 drives breast cancer progression via cell cycle regulation: diagnostic and therapeutic implications. Frontiers in oncology 0 41640445
2026 DSN1 promotes colorectal cancer metastasis by Inhibiting FZR1-Mediated ubiquitination of c-MYC. Experimental cell research 0 41713835
2024 DSN1 Interaction With Centromere-Associated Proteins Promotes Chromosomal Instability in Hepatocellular Carcinoma. Molecular carcinogenesis 0 39560395