Affinage

NCAPH

Condensin complex subunit 2 · UniProt Q15003

Length
741 aa
Mass
82.6 kDa
Annotated
2026-06-10
31 papers in source corpus 13 papers cited in narrative 13 extracted findings
Cross-family judge vs UniProt: tie faithfulness: 7/7 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

NCAPH (CAP-H) is the kleisin subunit of the condensin I complex and is required for mitotic chromosome condensation, sister chromatid resolution, and the structural integrity of centromeric and pericentromeric heterochromatin (PMID:16199875). It associates with mitotic chromosomes in a symmetric distribution along sister chromatids and localizes to nucleoli during interphase, where condensin contacts rDNA (PMID:11694586). CAP-H is essential for loading the non-SMC condensin I subunits onto chromosomes; its loss leaves the SMC core on chromatin but strips the regulatory subunits, and centromeric heterochromatin assembled without CAP-H cannot resist mitotic spindle forces (PMID:16199875). Condensin I activity is gated by phosphorylation: Cdk1 phosphorylation of a conserved residue in the CAP-H central region relieves terminal intrinsically disordered region (tIDR)-mediated self-suppression to fully activate the complex, while PP2A-B55 dephosphorylation drives condensin I dissociation and chromatid disassembly during mitotic exit [PMID:bio_10.1101_2025.09.08.674995]. Beyond bulk condensation, NCAPH stabilizes the Holliday junction resolvase GEN1 in chromatin at G2/M through an N-terminal interaction, resolving DNA inter-strand-crosslink-induced ultra-fine bridges and preventing sister-chromatid intertwinement and cytokinesis failure (PMID:36380731). During prolonged mitotic arrest, caspase-3 cleaves CAP-H to release condensin I from chromosomes, compromising chromosome integrity and promoting mitotic death (PMID:21151026). NCAPH protein abundance is controlled by TRIM21, which interacts with NCAPH via its PRY/SPRY and CC domains and ubiquitinates it at K11 through its RING domain to drive proteasomal degradation, autophagy induction, and suppression of AKT/mTOR signaling (PMID:39103348). In cancer, NCAPH is transcriptionally driven by MYBL2, E2F1, and FOXM1 (PMID:32200471, PMID:33311486, PMID:37260271) and acts as an oncogenic effector: it transcriptionally regulates E2F1 to stimulate PI3K/AKT/mTOR signaling (PMID:39991770), activates MEK/ERK signaling to promote proliferation (PMID:34974790), interacts with YAP1 to enhance nuclear translocation and cancer stem cell traits (PMID:40999529), and binds PD-L1 to block its degradation by competing with HIP1R, supporting an immunosuppressive tumor microenvironment (PMID:41386505).

Mechanistic history

Synthesis pass · year-by-year structured walk · 11 steps
  1. 2001 Medium

    Established the cell-cycle behavior and subcellular distribution of human CAP-H, showing it is a stable protein that relocalizes from interphase nucleoli to mitotic chromosomes, placing condensin downstream of histone H3 phosphorylation in condensation.

    Evidence Cell fractionation, immunofluorescence and cell cycle synchronization in human cells

    PMID:11694586

    Open questions at the time
    • Did not test functional requirement of CAP-H for condensation
    • rDNA association inferred from nucleolar localization, not directly demonstrated
  2. 2005 High

    Demonstrated that CAP-H is required to load the non-SMC condensin I subunits onto chromosomes and to maintain centromeric heterochromatin integrity, defining its core kleisin function in condensation and sister chromatid resolution.

    Evidence RNAi depletion, live imaging and chromosome fractionation in Drosophila S2 cells (ortholog Barren/CAP-H)

    PMID:16199875

    Open questions at the time
    • Mechanism by which CAP-H bridges SMC core to non-SMC subunits not structurally defined
    • Human conservation of heterochromatin role not directly tested here
  3. 2010 High

    Identified CAP-H as a caspase-3 substrate whose cleavage releases condensin I from chromosomes during prolonged mitotic arrest, linking condensin integrity to a mitotic death decision.

    Evidence Caspase cleavage assay, caspase-resistant mutant expression and DNA fragmentation assays in human cells

    PMID:21151026

    Open questions at the time
    • Cleavage site(s) and downstream signaling not fully mapped
    • Physiological contexts triggering this pathway beyond drug-induced arrest unclear
  4. 2020 Medium

    Placed NCAPH downstream of oncogenic transcription factors, showing MYBL2 and E2F1 (via HPV E7) directly bind its promoter to drive proliferation and migration.

    Evidence ChIP, luciferase reporter, knockdown and rescue assays in lung adenocarcinoma and cervical cancer cells

    PMID:32200471 PMID:33311486

    Open questions at the time
    • Whether transcriptional induction reflects condensin function or a moonlighting role unresolved
    • Feedback loop with E7/AP-1 specific to HPV context
  5. 2022 Medium

    Revealed a genome-stability role beyond bulk condensation, with NCAPH stabilizing the GEN1 resolvase in chromatin to resolve ICL-induced ultra-fine DNA bridges.

    Evidence Co-IP with N-terminal domain mapping, knockdown and chromosome segregation assays with ICL-inducing agents in human cells

    PMID:36380731

    Open questions at the time
    • Single Co-IP-based interaction without structural detail
    • Mechanism of GEN1 stabilization (direct shielding vs. recruitment) unknown
  6. 2022 Medium

    Connected NCAPH to MEK/ERK signaling as an oncogenic driver of proliferation and apoptosis suppression.

    Evidence Gain/loss-of-function, MEK inhibitor U0126, and xenograft in bladder cancer

    PMID:34974790

    Open questions at the time
    • Direct molecular link between NCAPH and MEK/ERK not defined
    • Whether effect is condensin-dependent unclear
  7. 2023 Medium

    Linked FOXM1-driven NCAPH expression to cancer cell stemness and chemoresistance through glycolytic metabolism.

    Evidence ChIP, dual-luciferase, Seahorse glycolysis and sphere formation assays in colon adenocarcinoma

    PMID:37260271

    Open questions at the time
    • Mechanism connecting NCAPH to glycolytic gene regulation undefined
    • Single lineage context
  8. 2024 High

    Defined post-translational control of NCAPH abundance, showing TRIM21 ubiquitinates NCAPH at K11 to drive degradation, autophagy, and AKT/mTOR suppression.

    Evidence Mass spectrometry, Co-IP, domain mutagenesis and ubiquitination assays in cervical cancer cells

    PMID:39103348

    Open questions at the time
    • Whether degraded pool is condensin-bound or free NCAPH unclear
    • Regulation of TRIM21 activity toward NCAPH not addressed
  9. 2025 Medium

    Expanded NCAPH's oncogenic interactome to YAP1 (Hippo) and PD-L1, showing it promotes YAP1 nuclear translocation/stemness and stabilizes PD-L1 by competing with HIP1R to support immune evasion.

    Evidence Co-IP, competition binding, peptide disruption (NPIDP), YAP1 inhibitor rescue and in vivo tumor assays in breast and other cancers

    PMID:40999529 PMID:41386505

    Open questions at the time
    • Co-IP-based interactions without structural or reciprocal validation
    • Direct vs. indirect nature of YAP1 dephosphorylation effect unresolved
  10. 2025 Medium

    Showed NCAPH transcriptionally regulates E2F1 to stimulate PI3K/AKT/mTOR and identified druggable synergy with mTOR and CDK inhibitors in prostate cancer.

    Evidence ChIP, knockdown, western blot, xenograft and inhibitor combination assays

    PMID:39991770

    Open questions at the time
    • How a condensin kleisin acts as a promoter-binding transcriptional regulator mechanistically unexplained
    • DNA-binding specificity of NCAPH not characterized
  11. 2025 High

    Reconstituted the phospho-regulatory logic of condensin I, defining Cdk1 phosphorylation of the CAP-H central region as relieving tIDR self-suppression and PP2A-B55 as reversing it to disassemble chromatids.

    Evidence In vitro reconstitution with recombinant proteins, phosphosite mutagenesis and Xenopus egg extract validation (preprint)

    PMID:bio_10.1101_2025.09.08.674995

    Open questions at the time
    • Preprint, not peer-reviewed
    • Precise central-region phosphoresidue and its structural consequence on the kleisin not fully resolved

Open questions

Synthesis pass · forward-looking unresolved questions
  • How NCAPH reconciles its core mitotic condensin function with reported moonlighting roles as a promoter-binding transcriptional regulator and oncogenic signaling hub remains unresolved.
  • No structural basis for proposed direct DNA/promoter binding
  • Whether oncogenic signaling effects depend on condensin assembly or a separable activity is untested
  • Most cancer mechanisms rest on single-lab Co-IP and inhibitor-rescue data

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0005198 structural molecule activity 2 GO:0140110 transcription regulator activity 1
Localization
GO:0005694 chromosome 2 GO:0000228 nuclear chromosome 1 GO:0005730 nucleolus 1
Pathway
R-HSA-1640170 Cell Cycle 2 R-HSA-392499 Metabolism of proteins 1 R-HSA-73894 DNA Repair 1
Complex memberships
condensin I

Evidence

Reading pass · 13 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2001 hCAP-H (NCAPH) protein levels remain constant throughout the cell cycle despite cell cycle-restricted transcription (highest in G2); hCAP-H associates with mitotic chromosomes in a non-uniform but symmetric distribution along sister chromatids during mitosis, and localizes to nucleoli during interphase together with hCAP-C and hCAP-E, suggesting condensin associates with rDNA. hCAP-H association with condensed chromatin was not observed in early chromosome condensation when histone H3 phosphorylation has already occurred, consistent with H3 phosphorylation preceding condensin-mediated condensation. Cell fractionation, immunofluorescence, in vivo imaging, cell cycle synchronization Molecular biology of the cell Medium 11694586
2005 Drosophila CAP-H/Barren (condensin I subunit, ortholog of NCAPH) is required for sister chromatid resolution and for maintaining structural integrity of centromeric and pericentromeric heterochromatin during mitosis. Depletion of Barren/CAP-H causes the condensin core SMC subunits to remain on chromatin while other condensin I non-SMC subunits do not, indicating CAP-H is essential for the association of the non-SMC condensin I subunits with chromosomes. Centromeric heterochromatin assembled without CAP-H cannot withstand mitotic spindle forces and undergoes irreversible distortion after bipolar attachment. RNAi depletion in Drosophila S2 cells, immunofluorescence, in vivo live imaging, chromosome fractionation Molecular and cellular biology High 16199875
2010 During prolonged mitotic arrest, caspase-3 is activated and cleaves CAP-H (NCAPH), a condensin I subunit. Depletion or cleavage of CAP-H causes loss of condensin I complex from chromosomes, compromising chromosome integrity and facilitating DNA fragmentation by caspase-activated DNase (CAD), thereby driving mitotic death. Expression of a caspase-resistant form of CAP-H abrogates mitotic death and allows cells to re-enter interphase after prolonged mitotic delay. Caspase cleavage assay, caspase-resistant mutant expression, immunofluorescence, cell death assays, DNA fragmentation assay Cell death and differentiation High 21151026
2020 MYBL2 transcription factor directly binds to the transcription start site (TSS) of NCAPH and upregulates its expression. Overexpression of NCAPH partially rescues cell death and migration blockage induced by MYBL2 knockdown, placing NCAPH downstream of MYBL2 in a proliferation/migration pathway in lung adenocarcinoma cells. Chromatin immunoprecipitation (ChIP) assay, siRNA knockdown, rescue overexpression, cell proliferation and migration assays Molecular and cellular biochemistry Medium 32200471
2020 HPV E7 upregulates NCAPH expression via E2F1, which binds directly to the NCAPH promoter to initiate transcription. In turn, NCAPH silencing reduces E7 transcription by promoting a shift in the AP-1 heterodimer from c-Fos/c-Jun to Fra-1/c-Jun, establishing a positive feedback loop between E7 and NCAPH. E7-mediated NCAPH overexpression activates the PI3K/AKT/SGK signaling pathway. ChIP assay (E2F1 binding to NCAPH promoter), luciferase reporter assay, siRNA knockdown, western blotting, AP-1 transcription factor analysis Cell death & disease Medium 33311486
2022 NCAPH interacts with GEN1 (a Holliday junction resolvase) at the N-terminus of NCAPH within chromatin. NCAPH stabilizes GEN1 in chromatin at G2/M phase. DNA inter-strand crosslink (ICL) induction increases expression and interaction of NCAPH and GEN1. NCAPH depletion exacerbates chromosome segregation errors and cytokinesis failure due to sister-chromatid intertwinement. NCAPH resolves DNA-ICL-induced ultra-fine DNA bridges by stabilizing GEN1, thereby ensuring proper chromosome separation and structural stability. Co-immunoprecipitation, domain mapping (N-terminus binding), siRNA knockdown, immunofluorescence, chromosome segregation and cytokinesis failure assays, ICL-inducing agent treatment Molecules and cells Medium 36380731
2022 NCAPH promotes bladder cancer cell proliferation and inhibits apoptosis through activation of the MEK/ERK signaling pathway. The MEK1/2 inhibitor U0126 blocks the increase in cell proliferation regulated by NCAPH overexpression, confirming pathway dependence. Gain- and loss-of-function experiments (overexpression and shRNA knockdown), MEK inhibitor treatment (U0126), western blotting, xenograft mouse model Cell cycle (Georgetown, Tex.) Medium 34974790
2024 TRIM21 (an E3 ubiquitin ligase) interacts with NCAPH and ubiquitinates it at the K11 lysine residue, decreasing NCAPH protein stability and promoting its degradation. TRIM21 combines with NCAPH through its PRY/SPRY and CC domains and accelerates NCAPH degradation through its RING domain. TRIM21-mediated NCAPH destabilization promotes autophagosome formation and reduces cell proliferation by suppressing the downstream AKT/mTOR pathway in cervical cancer cells. Mass spectrometry, co-immunoprecipitation, domain mutation analysis, ubiquitination assay, western blotting, autophagy assays Cell death & disease High 39103348
2023 FOXM1 functions as a transcription factor that directly activates NCAPH expression; FOXM1-mediated NCAPH upregulation promotes colon adenocarcinoma cell stemness and 5-FU resistance via the glycolytic pathway. Inhibition of glycolysis reverses the effect of NCAPH overexpression on stemness and resistance. Chromatin immunoprecipitation, dual-luciferase reporter assay, siRNA knockdown, glycolysis assay (Seahorse), sphere formation assay Anti-cancer drugs Medium 37260271
2025 NCAPH binds to PD-L1 and disrupts its degradation by competing with HIP1R (Huntingtin-interacting protein 1-related), leading to stabilization of PD-L1 protein and contributing to immunosuppressive tumor microenvironment. A disrupting peptide (NPIDP) that blocks the NCAPH-PD-L1 interaction suppresses tumor immune evasion. Additionally, topotecan (a topoisomerase I inhibitor) binds NCAPH and promotes its proteasomal degradation. Co-immunoprecipitation, competition binding assay, peptide disruption experiment, in vitro and in vivo tumor immune evasion assays, proteasomal degradation assay Cancer letters Medium 41386505
2025 NCAPH interacts with YAP1 (Hippo pathway effector), promotes LATS1 and YAP1 expression, dephosphorylation, and nuclear translocation, thereby enhancing breast cancer stem cell traits and malignant phenotypes. YAP1 inhibitor Verteporfin reverses NCAPH-driven breast cancer stem cell traits and malignant phenotypes. Co-immunoprecipitation, immunofluorescence co-localization, transcriptomic sequencing, GSEA, YAP1 inhibitor functional rescue experiment, in vitro and in vivo assays Stem cell research & therapy Medium 40999529
2025 NCAPH regulates E2F1 transcription by binding to the proximal promoter of E2F1 (as shown by ChIP analysis), subsequently stimulating the PI3K/AKT/mTOR pathway and activating downstream targets for cell cycle progression in prostate cancer cells. Combining NCAPH knockdown with mTOR inhibitor (Everolimus) or CDK inhibitor (Flavopiridol) demonstrates synergistic anti-tumor effects in vitro and in vivo. Chromatin immunoprecipitation (ChIP), siRNA knockdown, flow cytometry, western blotting, xenograft model, pharmacological inhibitor combination International journal of medical sciences Medium 39991770
2025 In vitro reconstitution established that the terminal intrinsically disordered regions (tIDRs) of non-SMC subunits of condensin I suppress its activity, and that Cdk1 phosphorylation relieves this self-suppression. Full activation of condensin I requires phosphorylation of a conserved residue in the central region of the kleisin subunit CAP-H (NCAPH). Conversely, PP2A-B55 induces dissociation of condensin I from reconstituted chromatids, driving their disassembly. The tIDRs and CAP-H central region are phosphorylated and dephosphorylated with distinct kinetics during mitotic entry and exit. In vitro reconstitution of mitotic chromatid assembly/disassembly with recombinant proteins, Cdk1/cyclin B phosphorylation assay, PP2A-B55 dephosphorylation assay, Xenopus egg extract complementary analysis, mutagenesis of phosphorylation sites bioRxivpreprint High bio_10.1101_2025.09.08.674995

Source papers

Stage 0 corpus · 31 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2005 The condensin I subunit Barren/CAP-H is essential for the structural integrity of centromeric heterochromatin during mitosis. Molecular and cellular biology 89 16199875
2017 NCAPH plays important roles in human colon cancer. Cell death & disease 68 28300828
2020 Overexpression of MYBL2 promotes proliferation and migration of non-small-cell lung cancer via upregulating NCAPH. Molecular and cellular biochemistry 43 32200471
2001 Cell cycle-dependent expression and nucleolar localization of hCAP-H. Molecular biology of the cell 41 11694586
2020 HPV E7-mediated NCAPH ectopic expression regulates the carcinogenesis of cervical carcinoma via PI3K/AKT/SGK pathway. Cell death & disease 38 33311486
2019 Non-SMC Condensin I Complex Subunit H (NCAPH) Is Associated with Lymphangiogenesis and Drug Resistance in Oral Squamous Cell Carcinoma. Journal of clinical medicine 26 31892156
2010 Caspase-3-mediated degradation of condensin Cap-H regulates mitotic cell death. Cell death and differentiation 24 21151026
2020 NCAPH Is Required for Proliferation, Migration and Invasion of Non-small-cell Lung Cancer Cells. Anticancer research 22 32487618
2022 NCAPH promotes cell proliferation and inhibits cell apoptosis of bladder cancer cells through MEK/ERK signaling pathway. Cell cycle (Georgetown, Tex.) 21 34974790
2019 Micro-ribonucleic acid expression signature of metastatic castration-resistant prostate cancer: Regulation of NCAPH by antitumor miR-199a/b-3p. International journal of urology : official journal of the Japanese Urological Association 21 30818424
2024 NCAPH, ubiquitinated by TRIM21, promotes cell proliferation by inhibiting autophagy of cervical cancer through AKT/mTOR dependent signaling. Cell death & disease 17 39103348
2021 NCAPH regulates gastric cancer progression through DNA damage response. Neoplasma 16 34962823
2020 NCAPH is upregulated in endometrial cancer and associated with poor clinicopathologic characteristics. Annals of human genetics 16 32628282
2021 Expression and Clinical Significance of the NCAPH, AGGF1, and FOXC2 Proteins in Serous Ovarian Cancer. Cancer management and research 14 34584452
2022 NCAPH promotes proliferation as well as motility of breast cancer cells by activating the PI3K/AKT pathway. Physiology international 11 36067021
2023 FOXM1/NCAPH activates glycolysis to promote colon adenocarcinoma stemness and 5-FU resistance. Anti-cancer drugs 10 37260271
2020 NCAPH is negatively associated with Mcl‑1 in non‑small cell lung cancer. Molecular medicine reports 10 32945371
2024 NCAPH drives breast cancer progression and identifies a gene signature that predicts luminal a tumour recurrence. Clinical and translational medicine 7 38344872
2024 The role of NCAPH in cancer treatment. Cellular signalling 7 38901722
2022 An integrative pan-cancer analysis reveals the carcinogenic effects of NCAPH in human cancer. Mathematical biosciences and engineering : MBE 7 36650758
2024 ZCCHC3 and Efp coordinately contribute to the pathophysiology of triple-negative breast cancer by modulating NCAPH. Biochemical and biophysical research communications 6 39276521
2022 NCAPH Stabilizes GEN1 in Chromatin to Resolve Ultra-Fine DNA Bridges and Maintain Chromosome Stability. Molecules and cells 6 36380731
2024 MiR-1976/NCAPH/P65 axis inhibits the malignant phenotypes of lung adenocarcinoma. Scientific reports 5 38755247
2025 NCAPH promotes glucose metabolism reprogramming and cell stemness in ovarian cancer cells through the MEK/ERK/PD-L1 pathway. Journal of ovarian research 4 40259316
2024 circEIF3I Promotes Colorectal Cancer Metastasis by Regulating the miR-328-3p/NCAPH Axis. Molecular carcinogenesis 4 39620395
2025 NCAPH Promotes the Proliferation of Prostate Cancer Cells Via Modulating the E2F1 Mediated PI3K/AKT/mTOR Axis. International journal of medical sciences 3 39991770
2025 MiR-1976 affects lung squamous cell carcinoma development by targeting NCAPH. Journal of applied genetics 2 40699282
2025 NCAPH-YAP1 interaction promotes breast cancer stemness and tumor progression. Stem cell research & therapy 1 40999529
2025 NCAPH promotes immune evasion via inhibiting PD-L1 protein degradation in head and neck squamous cell carcinoma. Cancer letters 1 41386505
2026 NCAPH as an onco-structural hub linking chromatin architecture to metabolic reprogramming, immune evasion, and therapy resistance. Critical reviews in oncology/hematology 0 41825578
2023 NCAPH Drives Breast Cancer Progression and Identifies a Gene Signature that Predicts Luminal A Tumor Recurrence. Research square 0 37886490

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