Affinage

CENPN

Centromere protein N · UniProt Q96H22

Length
339 aa
Mass
39.6 kDa
Annotated
2026-04-28
18 papers in source corpus 11 papers cited in narrative 11 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

CENP-N is a constitutive centromere-associated network (CCAN) protein that serves as the primary reader of CENP-A nucleosomes, coupling centromeric chromatin identity to kinetochore assembly and higher-order chromatin architecture. It selectively recognizes CENP-A nucleosomes—but not H3 nucleosomes—through charge and shape complementarity with the CENP-A L1 loop and extensive contacts with nucleosomal DNA, a specificity mechanism resolved by independent cryo-EM structures (PMID:29280735, PMID:29269420); stable centromeric recruitment additionally requires a coincident interaction with nucleosome-bound CENP-C, and its binding is gated by cell cycle–dependent exposure of the CENP-A RG loop during S/G2 phase (PMID:25943375, PMID:22100916). Beyond nucleosome recognition, CENP-N promotes centromeric chromatin compaction by stacking adjacent nucleosomes via its α6 helix (PMID:35422519), and its mitotic function is regulated by CDK1 phosphorylation that modulates CENP-L interaction and is required for accurate chromosome segregation (PMID:37365681). Loss of CENP-N impairs recruitment of CENP-H/I/K, reduces nascent CENP-A incorporation, and activates the spindle assembly checkpoint (PMID:19543270, PMID:37365681).

Mechanistic history

Synthesis pass · year-by-year structured walk · 8 steps
  1. 2009 High

    Establishing that CENP-N is the selective reader of CENP-A nucleosomes answered how the cell distinguishes centromeric from canonical chromatin for kinetochore nucleation.

    Evidence Nucleosome binding assays, co-IP, siRNA knockdown, and mutagenesis in human cells

    PMID:19543270

    Open questions at the time
    • Structural basis of CENP-A selectivity was unknown
    • Mechanism by which CENP-N recruits downstream CCAN subunits was not resolved
    • Cell cycle regulation of the CENP-N–CENP-A interaction was uncharacterized
  2. 2011 High

    Live-cell FRET and FRAP demonstrated that CENP-N is stably bound at centromeres only during S/G2 and exchanges rapidly in G1/mitosis, establishing cell cycle dynamics and suggesting a fidelity role during centromeric replication.

    Evidence FRET and FRAP in living human cells with cell cycle synchronization

    PMID:22100916

    Open questions at the time
    • Molecular basis for cell cycle–dependent exchange was unknown
    • Whether CENP-N dynamics are transcriptionally or post-translationally controlled was not determined
  3. 2015 High

    The discovery that the CENP-A RG loop drives centromeric chromatin compaction that conceals the CENP-N binding site until S phase explained the cell cycle gating of CENP-N recruitment.

    Evidence Structural and mutational analysis of CENP-A chromatin with cell cycle–resolved CENP-N localization

    PMID:25943375

    Open questions at the time
    • How chromatin decompaction is triggered at S phase entry was not identified
    • Whether additional factors besides the RG loop regulate accessibility was unclear
  4. 2017 High

    Two independent cryo-EM structures of the CENP-N–CENP-A nucleosome complex resolved, at near-atomic level, how CENP-N decodes the CENP-A L1 loop and engages nucleosomal DNA, and showed that coincident CENP-C binding reinforces stable centromere recruitment.

    Evidence Cryo-EM structures with mutagenesis, biophysical assays, and Xenopus residue-swapping experiments

    PMID:29269420 PMID:29280735

    Open questions at the time
    • How the CENP-N–nucleosome interaction integrates into the full CCAN assembly was not resolved
    • Whether CENP-N binding alters nucleosome dynamics or histone modification was unknown
  5. 2019 Medium

    Identification of HSC70 as a stabilizer of CENP-N via inhibition of proteasomal degradation (in Bombyx mori) provided the first evidence that CENP-N turnover is actively regulated by the ubiquitin-proteasome pathway.

    Evidence Affinity purification/MS, co-IP, and RNAi in silkworm cells

    PMID:31756960

    Open questions at the time
    • Conservation of HSC70-mediated stabilization in mammalian cells was not tested
    • The E3 ligase targeting CENP-N was not identified
    • Single Co-IP/MS identification without reciprocal validation in mammalian system
  6. 2022 High

    Cryo-EM structures of CENP-N–mediated nucleosome stacks revealed that the α6 helix of CENP-N contacts DNA on an adjacent nucleosome, establishing CENP-N as a chromatin architectural factor that compacts centromeric arrays.

    Evidence Cryo-EM of nucleosome stacks, mutagenesis, biophysical and cellular chromatin compaction assays

    PMID:35422519

    Open questions at the time
    • How compaction by CENP-N is coordinated with other compaction factors (e.g., cohesin) at centromeres was not addressed
    • Whether α6-mediated stacking is essential for kinetochore function in vivo was not tested genetically
  7. 2023 High

    Identification of CDK1-mediated phosphorylation of CENP-N during mitosis, which modulates the CENP-L–CENP-N interaction, established a direct post-translational mechanism linking mitotic kinase signaling to CCAN dynamics and chromosome alignment.

    Evidence Mass spectrometry, CDK1 kinase assays, phosphomimetic/phospho-dead mutants, chromosome alignment and SAC assays in human cells

    PMID:37365681

    Open questions at the time
    • Whether other mitotic kinases also phosphorylate CENP-N was not explored
    • Structural basis for how phosphorylation disrupts CENP-L binding was not determined
  8. 2024 Medium

    Reports of CENP-N interacting with STAT3 and SEPT9 in cancer cells to modulate signaling, glycolysis, and autophagy raised the question of whether CENP-N has non-centromeric moonlighting functions in tumor biology.

    Evidence Co-IP, GST pull-down, ChIP, luciferase reporters, xenograft models in nasopharyngeal and colorectal carcinoma

    PMID:37776538 PMID:39424682 PMID:40458725

    Open questions at the time
    • All non-centromeric functions reported from single laboratories without independent replication
    • Whether these activities occur in normal (non-cancer) cells is unknown
    • Mechanistic link between centromeric and non-centromeric roles is entirely uncharacterized
    • SEPT9 methylation mechanism attributed to CENP-N lacks biochemical reconstitution

Open questions

Synthesis pass · forward-looking unresolved questions
  • How CENP-N integrates into the full CCAN architecture on a native centromeric chromatin fiber, and whether its non-centromeric functions in cancer cells reflect bona fide moonlighting or overexpression artifacts, remain open.
  • No structure of CENP-N within a complete CCAN on a centromeric chromatin fiber
  • Non-centromeric functions not independently replicated
  • No genetic disease linkage established for CENPN loss-of-function in humans

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0003677 DNA binding 3 GO:0042393 histone binding 3 GO:0005198 structural molecule activity 1
Localization
GO:0005694 chromosome 7 GO:0005634 nucleus 2
Pathway
R-HSA-1640170 Cell Cycle 3 R-HSA-4839726 Chromatin organization 2
Partners
CENP-ACENP-CCENP-HCENP-ICENP-KCENP-L
Complex memberships
CCAN (constitutive centromere-associated network)

Evidence

Reading pass · 11 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2009 CENP-N selectively binds CENP-A nucleosomes but not canonical H3 nucleosomes in a DNA sequence-independent manner; this binding requires nucleosomal context (not soluble CENP-A-H4 tetramers). Mutations reducing CENP-N affinity for CENP-A nucleosomes impair CENP-N localization and dominant-negatively reduce recruitment of CENP-H, CENP-I, and CENP-K to centromeres. siRNA depletion of CENP-N reduces nascent CENP-A incorporation into centromeric chromatin. Co-immunoprecipitation, nucleosome binding assays, site-directed mutagenesis, siRNA knockdown with centromere localization readout Nature cell biology High 19543270
2017 Cryo-EM and biochemical studies reveal that CENP-N uses charge and space complementarity to decode the L1 loop unique to CENP-A, and engages in extensive interactions with a 15-bp segment of nucleosomal DNA. Stable centromere recruitment of CENP-N additionally requires a coincident interaction with a binding motif on nucleosome-bound CENP-C. Cryo-EM structure, biophysical binding assays, site-directed mutagenesis, cell biological localization assays eLife High 29280735
2017 Cryo-EM structure of the human CENP-N–CENP-A nucleosome complex shows CENP-N confers binding specificity through interactions with the L1 loop of CENP-A stabilized by electrostatic interactions with nucleosomal DNA; residue-swapping experiments in Xenopus confirm conservation and co-evolution of the CENP-N/CENP-A interface. Cryo-EM, biophysical assays, mutational/residue-swapping analysis, cell biology Science (New York, N.Y.) High 29269420
2015 The CENP-A-specific RG loop (Arg80/Gly81) plays a dual regulatory role: it assists formation of a compact 'ladder-like' CENP-A chromatin structure that conceals the loop and prevents CENP-N binding; upon G1/S-phase transition, centromeric chromatin opens, exposing the RG loop and enabling CENP-N recruitment prior to cell division. Structural analysis of CENP-A chromatin, mutational analysis of the RG loop, cell cycle synchronization with CENP-N localization assays Genes & development High 25943375
2011 FRET analysis in living cells shows the N-terminus of CENP-N is in close proximity to the N-terminus of CENP-A in vivo. CENP-N is stably bound to kinetochores during S phase and G2, largely absent during mitosis and G1, and undergoes rapid exchange in G1 that stabilizes in mid-S phase; this dynamic pattern suggests CENP-N functions as a fidelity factor during centromeric replication. FRET in living cells, fluorescence recovery after photobleaching (FRAP), cell cycle synchronization with live-cell imaging Journal of cell science High 22100916
2022 CENP-N promotes compaction of centromeric chromatin by stacking CENP-A-containing mononucleosomes and nucleosomal arrays through an interaction between the α6 helix of CENP-N and the DNA of a neighboring nucleosome; cryo-EM structures of CENP-N-mediated nucleosome stacks were determined and this interaction was shown to be responsible for densely packed centromeric chromatin in cells. Cryo-EM structure of nucleosome stacks, biophysical characterization, mutagenesis, cell biological chromatin compaction assays Nature structural & molecular biology High 35422519
2023 CDK1 phosphorylates CENP-N during mitosis (identified by mass spectrometry); this phosphorylation modulates the CENP-L–CENP-N interaction and is required for accurate chromosome segregation and CCAN organization. Perturbation of CENP-N phosphorylation prevents proper chromosome alignment and activates the spindle assembly checkpoint. Mass spectrometry identification of phosphorylation sites, CDK1 kinase assays, phosphomimetic/phospho-dead mutant cell biology, chromosome alignment and SAC assays Journal of molecular cell biology High 37365681
2019 In Bombyx mori (silkworm), HSC70 (heat shock cognate 70) interacts with CENP-N and stabilizes it by inhibiting the ubiquitin-proteasome pathway, thereby controlling cell cycle-regulated degradation of CENP-N at centromeres. Affinity purification of CENP-N complex followed by mass spectrometry, co-immunoprecipitation, RNAi, cellular localization International journal of molecular sciences Medium 31756960
2024 CENP-N inhibits autophagy in nasopharyngeal carcinoma cells by blocking nuclear translocation of p-CREB, reducing p-CREB binding to the VAMP8 promoter and suppressing VAMP8 transcription; knockdown of VAMP8 reverses the PTX-sensitizing effect of CENP-N knockdown, placing CENP-N upstream of CREB–VAMP8 in an autophagy-regulatory axis. shRNA knockdown, transcriptome sequencing, ChIP assay, luciferase reporter, Western blot, xenograft model Autophagy Medium 37776538
2025 CENP-N directly binds STAT3 (confirmed by co-immunoprecipitation, GST pull-down, and protein truncation tests) and promotes STAT3 phosphorylation and nuclear translocation, which in turn drives USP37 transcription (confirmed by ChIP and luciferase reporter assays), thereby promoting invasion and metastasis of nasopharyngeal carcinoma. Co-immunoprecipitation, GST pull-down, protein truncation mapping, luciferase reporter, ChIP, transcriptome sequencing, in vivo xenograft metastasis model Frontiers in oncology Medium 40458725
2024 CENP-N directly interacts with SEPT9 and enhances methylation of SEPT9 at specific lysine residues, upregulating key glycolytic enzymes and promoting aerobic glycolysis, CRC cell proliferation, migration, and liver metastasis in vivo. Co-immunoprecipitation, methylation-specific PCR, ChIP assay, in vitro and in vivo functional assays, single-cell RNA sequencing Clinical & experimental metastasis Low 39424682

Source papers

Stage 0 corpus · 18 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2009 Centromere assembly requires the direct recognition of CENP-A nucleosomes by CENP-N. Nature cell biology 243 19543270
2017 Decoding the centromeric nucleosome through CENP-N. eLife 101 29280735
2017 Structural mechanisms of centromeric nucleosome recognition by the kinetochore protein CENP-N. Science (New York, N.Y.) 99 29269420
2015 Structural transitions of centromeric chromatin regulate the cell cycle-dependent recruitment of CENP-N. Genes & development 65 25943375
2011 Dynamics of CENP-N kinetochore binding during the cell cycle. Journal of cell science 54 22100916
2022 CENP-N promotes the compaction of centromeric chromatin. Nature structural & molecular biology 45 35422519
2024 CENPN suppresses autophagy and increases paclitaxel resistance in nasopharyngeal carcinoma cells by inhibiting the CREB-VAMP8 signaling axis. Autophagy 21 37776538
2021 CENPN Acts as a Novel Biomarker that Correlates With the Malignant Phenotypes of Glioma Cells. Frontiers in genetics 16 34646306
2023 Dynamic phosphorylation of CENP-N by CDK1 guides accurate chromosome segregation in mitosis. Journal of molecular cell biology 13 37365681
2025 Diagnostics and immunological function of CENPN in human tumors: from pan-cancer analysis to validation in breast cancer. Translational cancer research 12 40104708
2023 Clinical implications and immune features of CENPN in breast cancer. BMC cancer 8 37697245
2022 LncRNA FAM225A activates the cGAS-STING signaling pathway by combining FUS to promote CENP-N expression and regulates the progression of nasopharyngeal carcinoma. Pathology, research and practice 8 35809496
2023 Knockdown of CENPN Inhibits Glucose Metabolism and Induces G1 Arrest in Esophageal Cancer Cells by Regulating PI3K/AKT Signaling Pathway. Hormone and metabolic research = Hormon- und Stoffwechselforschung = Hormones et metabolisme 5 37127048
2023 Enhancing nasopharyngeal carcinoma cell radiosensitivity by suppressing AKT/mTOR via CENP-N knockdown. Journal of translational medicine 5 37940975
2019 Heat Shock Cognate 70 Functions as A Chaperone for the Stability of Kinetochore Protein CENP-N in Holocentric Insect Silkworms. International journal of molecular sciences 5 31756960
2024 Disrupting CENP-N mediated SEPT9 methylation as a strategy to inhibit aerobic glycolysis and liver metastasis in colorectal cancer. Clinical & experimental metastasis 3 39424682
2024 CENPN contributes to pancreatic carcinoma progression through the MDM2-mediated p53 signaling pathway. Archives of medical science : AMS 2 39649279
2025 The CENPN/STAT3/USP37 signaling axis promotes invasion, migration and metastasis in nasopharyngeal carcinoma. Frontiers in oncology 0 40458725