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Showing NTMT1 — NRMT1 is a alias.

NTMT1

N-terminal Xaa-Pro-Lys N-methyltransferase 1 · UniProt Q9BV86

Length
223 aa
Mass
25.4 kDa
Annotated
2026-06-10
16 papers in source corpus 13 papers cited in narrative 14 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 7/7 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

NTMT1 (NRMT1) is the founding eukaryotic protein alpha-N-terminal methyltransferase, catalyzing mono-, di-, and trimethylation of the free alpha-amino group of substrates bearing an (Ala/Pro/Ser)-Pro-Lys N-terminal motif using SAM as methyl donor (PMID:20668449). Acting distributively, it can install all three methylation states, in contrast to its homolog NRMT2, which is principally a monomethylase recognizing the same consensus (PMID:24090352); NRMT1 functions as a homodimer and is converted to a more active, more stable form upon heterotrimer formation with NRMT2, an activation that does not require NRMT2 catalytic activity and reflects a scaffold/stabilization mechanism rather than substrate priming (PMID:30151928). Through N-terminal methylation of substrates including RCC1, RB, CENP-A, SET, OLA1, and PAD1 (PMID:20668449, PMID:28266506, PMID:31857877, PMID:39287128), NTMT1 governs bipolar spindle formation and chromosome segregation — loss of RCC1 or CENP-A trimethylation produces multipolar spindles, lagging chromosomes, and reduced centromeric CCAN loading (PMID:20668449, PMID:28266506). The enzyme is required for genome maintenance and DNA double-strand break repair, and its loss sensitizes cells to genotoxic stress while enhancing proliferation and tumorigenicity, consistent with a tumor-suppressor role (PMID:25843235, PMID:25909287). NTMT1 also controls RB-mediated transcriptional repression: its loss in mice deregulates RB phosphorylation and degradation and de-represses RB cell-cycle and apoptotic targets, with downstream consequences for neural stem cell quiescence (PMID:34711807). NTMT1 expression is transcriptionally driven by CREB1, which binds its promoter to support recovery from serum starvation and muscle cell differentiation, where NTMT1 loss abolishes Pax7 and redirects myoblasts toward an osteoblast-like fate (PMID:34403304). Substrate recognition is structurally defined by the peptide-binding channel, where cancer-associated mutations and peptidomimetic inhibitors that bind competitively to the peptide site alter or block trimethylation (PMID:28556566, PMID:32689795).

Mechanistic history

Synthesis pass · year-by-year structured walk · 10 steps
  1. 2010 High

    Established that a dedicated enzyme installs methylation on protein N-terminal alpha-amino groups, defining NRMT1 as the first eukaryotic alpha-N-methyltransferase and linking the modification to mitotic fidelity.

    Evidence In vitro methyltransferase assays, RCC1 substrate docking/mutagenesis, and siRNA knockdown with mitotic spindle readouts

    PMID:20668449

    Open questions at the time
    • Substrate scope beyond RCC1 and RB undefined
    • Structural basis of motif recognition not yet resolved
  2. 2013 High

    Resolved the division of labor between paralogs, showing NRMT1 is a distributive tri-methylase while NRMT2 is a monomethylase on the same consensus.

    Evidence In vitro enzyme assays with MS and co-expression experiments

    PMID:24090352

    Open questions at the time
    • Mechanism of NRMT1/NRMT2 cooperation (priming vs. stabilization) unresolved at this stage
  3. 2015 High

    Defined the organismal and genome-maintenance requirement for NRMT1, connecting its loss to oxidative damage handling and DNA repair deficits.

    Evidence Constitutive knockout mouse phenotyping, ROS measurement, and fibroblast oxidative damage assays; parallel breast cancer knockdown studies

    PMID:25843235 PMID:25909287

    Open questions at the time
    • No direct biochemical mechanism linking N-terminal methylation to DSB repair
    • Causal substrate driving the repair phenotype not identified
  4. 2017 High

    Identified CENP-A as an in vivo trimethylation target and the peptide-binding channel as a structural determinant of methylation-state specificity, explaining how cancer mutations reprogram enzyme output.

    Evidence In vivo trimethylation assays, centromere immunofluorescence; site-directed mutagenesis of cancer mutants with in vitro activity assays

    PMID:28266506 PMID:28556566

    Open questions at the time
    • Full crystal structure of the substrate complex not yet available
    • How altered methylation states affect tumorigenesis in vivo untested
  5. 2018 High

    Settled the paralog cooperation mechanism: NRMT2 forms a heterotrimer with the NRMT1 homodimer and activates it by increasing stability and substrate affinity, independent of NRMT2 catalysis.

    Evidence Analytical ultracentrifugation, reciprocal Co-IP, half-life assays, and catalytic-dead rescue

    PMID:30151928

    Open questions at the time
    • Structural model of the heterotrimer not experimentally determined
    • Physiological contexts requiring heterotrimer activation unclear
  6. 2019 Medium

    Expanded the in vivo substrate repertoire via activity-based profiling, identifying OLA1 as a cellular NTMT1 target.

    Evidence Hey-SAM chemoproteomic profiling with CRISPR-Cas9 knockout validation and MS

    PMID:31857877

    Open questions at the time
    • Functional consequence of OLA1 N-terminal methylation not established
  7. 2020 High

    Provided the structural and chemical-biology toolkit, with a co-crystal structure showing peptide-competitive, SAM-noncompetitive inhibition and a cell-permeable analogue achieving target engagement.

    Evidence Co-crystallization/X-ray structure with BM30, IC50 assays, 41-MT selectivity panel, cellular RCC1/SET methylation readout

    PMID:32689795

    Open questions at the time
    • In vivo efficacy of inhibitors untested
    • Cross-reactivity boundaries only partially mapped
  8. 2021 Medium

    Placed NRMT1 in a transcriptional circuit (CREB1-driven) and downstream signaling axes, controlling RB-dependent repression in neurogenesis and CREB1-dependent myogenic differentiation.

    Evidence Knockout mouse RB phosphorylation/target gene analysis; luciferase/promoter binding and CRISPR knockout in C2C12 cells; bisubstrate inhibitor chemoproteomics defining HemK2-Trm112 cross-reactivity

    PMID:34192867 PMID:34403304 PMID:34711807

    Open questions at the time
    • Direct substrate mediating RB regulation not pinned down
    • Mechanism linking N-terminal methylation to Pax7/lineage choice unresolved
  9. 2024 Medium

    Extended substrate-level consequences of methylation, showing NTMT1 methylation of PAD1 stabilizes it and remodels its interactions without altering its catalytic activity.

    Evidence Biochemical methylation, cellular half-life, and Co-IP/interaction proteomics with WT vs. non-methylatable PAD1

    PMID:39287128

    Open questions at the time
    • Physiological pathway impacted by PAD1 stabilization unclear
    • Generalizability of methylation-driven half-life control across substrates untested
  10. 2025 Medium

    Linked NRMT1 loss to progressive neuroinflammation via p35-to-p25 cleavage and glial activation, connecting its neurogenesis role to neurodegeneration.

    Evidence Constitutive Nrmt1-/- mouse with p35/p25 Western blots, cytokine and complement assays, glial immunofluorescence (preprint)

    Open questions at the time
    • Preprint, single lab, not peer-reviewed
    • Mechanistic link from N-terminal methylation to p35/p25 processing not biochemically defined

Open questions

Synthesis pass · forward-looking unresolved questions
  • How NTMT1 substrate selection is regulated in different tissues and which specific methylated substrates drive each phenotype (DNA repair, neurogenesis, myogenesis) remain open.
  • Causal substrate for each in vivo phenotype unresolved
  • No structure of the activated NRMT1/NRMT2 heterotrimer
  • Tissue-specific regulation of activity beyond CREB1 transcription unknown

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0016740 transferase activity 6 GO:0140096 catalytic activity, acting on a protein 3
Localization
GO:0005634 nucleus 2
Pathway
R-HSA-1266738 Developmental Biology 2 R-HSA-1640170 Cell Cycle 2 R-HSA-392499 Metabolism of proteins 2 R-HSA-73894 DNA Repair 2
Partners
CENP-ANRMT2OLA1PAD1RB1RCC1SET
Complex memberships
NRMT1 homodimerNRMT1-NRMT2 heterotrimer

Evidence

Reading pass · 14 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2010 NRMT1 (NRMT) is the first identified eukaryotic alpha-N-methyltransferase, catalyzing mono-, di-, and trimethylation of the free alpha-amino group of proteins bearing the N-terminal motif (Ala/Pro/Ser)-Pro-Lys (after Met cleavage). Substrates include RCC1 and retinoblastoma protein (RB). The NRMT recognition sequence was defined by substrate docking and mutational analysis of RCC1. Knockdown of NRMT recapitulates the multi-spindle phenotype seen with methylation-defective RCC1 mutants, establishing a role in bipolar spindle formation and chromosome segregation. In vitro methyltransferase assay, substrate docking, mutational analysis of RCC1, siRNA knockdown with mitotic phenotype readout, mass spectrometry Nature High 20668449
2013 NRMT1 is a distributive methyltransferase capable of mono-, di-, and trimethylation of N-terminal substrates, whereas its homolog NRMT2 is primarily a monomethylase recognizing the same consensus sequences. Concurrent expression of NRMT1 and NRMT2 accelerates production of trimethylation, with NRMT2 proposed to prime substrates for NRMT1-mediated trimethylation. In vitro enzyme assays, mass spectrometry, co-expression experiments The Biochemical Journal High 24090352
2017 CENP-A undergoes alpha-amino trimethylation by NRMT1 in vivo. Loss of this trimethylation reduces CENP-T and CENP-I CCAN components at the centromere, causes lagging chromosomes and spindle pole defects, and reduces cell survival. In vivo trimethylation assay, NRMT knockdown/knockout, immunofluorescence at centromeres, chromosome segregation assays Nature Communications High 28266506
2015 Complete loss of NRMT1 in knockout mice results in decreased body size, female-specific infertility, kyphosis, decreased mitochondrial function, and early-onset liver degeneration. NRMT1 knockout mouse embryonic fibroblasts show decreased capacity for handling oxidative damage, positioning NRMT1 as required for normal DNA repair and genome maintenance. Constitutive knockout mouse generation, phenotypic analysis, ROS measurement, fibroblast oxidative damage assays Mechanisms of Ageing and Development High 25843235
2015 NRMT1 knockdown significantly enhances sensitivity of breast cancer cell lines to etoposide and gamma-irradiation, and increases proliferation, invasive potential, anchorage-independent growth, and xenograft tumor size, positioning NRMT1 as a tumor suppressor involved in DNA double-strand break repair. siRNA knockdown, DNA damage sensitivity assays (etoposide, gamma-irradiation), cell proliferation, invasion, soft agar, xenograft Oncotarget Medium 25909287
2017 Cancer-associated NRMT1 mutants N209I (endometrial cancer) and P211S (lung cancer), located in the peptide-binding channel, display decreased trimethylase activity and increased mono/dimethylase activity with slower trimethylation rates and requirement for higher substrate concentration, identifying the peptide-binding channel as a structural determinant of enzyme specificity distinct from active-site aromatic residues. Site-directed mutagenesis of active-site aromatic residues and cancer mutants, in vitro enzyme activity assays, expression in WT and NRMT1-null cells Protein Science High 28556566
2018 NRMT1 primarily exists as a homodimer while NRMT2 exists as a monomer; when co-expressed they form a heterotrimer. NRMT2 increases NRMT1 stability (half-life) and substrate affinity, thereby activating NRMT1 trimethylation activity. The catalytic activity of NRMT2 is not required for this activation, supporting a stability/scaffold model rather than a priming model. Analytical ultracentrifugation, co-immunoprecipitation, molecular modeling, half-life assays, enzyme activity assays Protein Science High 30151928
2019 Activity-based substrate profiling using Hey-SAM identified OLA1 (Obg-like ATPase 1) as a novel substrate of NTMT1 methylated in vivo; this was validated using NTMT1 knockout HEK293FT cells generated by CRISPR-Cas9. Activity-based chemoproteomic profiling with Hey-SAM, CRISPR-Cas9 knockout validation, MS Chemical Science Medium 31857877
2020 Crystal structure of NTMT1 co-crystallized with peptidomimetic inhibitor BM30 reveals that the compound is a competitive inhibitor to the peptide substrate and noncompetitive to SAM, binding in the peptide substrate binding site. BM30 shows >100-fold selectivity for NTMT1/2 over 41 other methyltransferases. A cell-permeable analogue DC432 decreases N-terminal methylation of RCC1 and SET in HCT116 cells. Cocrystallization/X-ray structure, biochemical IC50 assays, selectivity panel against 41 MTs, cellular N-terminal methylation assay Journal of Medicinal Chemistry High 32689795
2021 NRMT1 loss in knockout mice causes misregulation of RB phosphorylation and degradation, and de-repression of RB target genes involved in cell cycle as well as the apoptosis-promoting RB target Noxa, establishing that NRMT1 regulates RB transcriptional repression during neurogenesis to promote neural stem cell quiescence. Constitutive Nrmt1-/- mouse, Western blotting for RB phosphorylation/degradation, gene expression analysis of RB targets, immunofluorescence, behavioral assays Cell Death & Disease Medium 34711807
2021 CREB1 is the major transcriptional activator of NRMT1; CREB1 binds the NRMT1 minimal promoter and drives its expression during recovery from serum starvation and muscle cell differentiation. Knockout of NRMT1 in C2C12 myoblasts abolishes Pax7 expression, prevents muscle differentiation, and causes transdifferentiation toward an osteoblast-like fate. Luciferase reporter assay, promoter binding assay, CRISPR/Cas9 knockout in C2C12 cells, alkaline phosphatase and collagen expression assays, serum starvation/differentiation experiments Transcription Medium 34403304
2021 A bisubstrate NTMT1 inhibitor NAH-C3-GPKK also potently inhibits the methyltransferase complex HemK2-Trm112 (KMT9-Trm112), as revealed by chemoproteomic pulldown with a biotinylated probe analogue; this cross-reactivity defines a selectivity boundary for NTMT1 bisubstrate inhibitors. Chemoproteomic pulldown, biochemical inhibition assays, competitor displacement with NAH-C3-GPKK ACS Chemical Biology Medium 34192867
2024 PAD1 (protein arginine deiminase 1) is a substrate of NTMT1; NTMT1-mediated Nα-methylation of PAD1 increases PAD1 protein half-life and modulates its protein-protein interactions in HEK293T cells without affecting PAD1 enzymatic activity or cellular localization. Biochemical methylation assay, cellular half-life assay, co-immunoprecipitation/proteomic interaction profiling in HEK293T cells with WT vs. non-methylatable PAD1 Journal of Proteome Research Medium 39287128
2025 In Nrmt1-/- mice, onset of neuronal apoptosis corresponds to increased cleavage of p35 into the CDK5 activator p25, which promotes neuroinflammation. Nrmt1-/- brains exhibit pro-inflammatory cytokine signaling, astrogliosis, complement activation, microgliosis, and compromised blood-brain barrier markers, with no compensatory anti-inflammatory response, linking NRMT1-dependent neurogenesis defects to progressive neuroinflammation and neurodegeneration. Constitutive Nrmt1-/- mouse, Western blotting for p35/p25, cytokine assays, immunofluorescence for glial markers, complement assays bioRxivpreprint Medium

Source papers

Stage 0 corpus · 16 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2010 NRMT is an alpha-N-methyltransferase that methylates RCC1 and retinoblastoma protein. Nature 111 20668449
2017 α-amino trimethylation of CENP-A by NRMT is required for full recruitment of the centromere. Nature communications 61 28266506
2013 NRMT2 is an N-terminal monomethylase that primes for its homologue NRMT1. The Biochemical journal 40 24090352
2015 NRMT1 knockout mice exhibit phenotypes associated with impaired DNA repair and premature aging. Mechanisms of ageing and development 37 25843235
2015 Loss of the N-terminal methyltransferase NRMT1 increases sensitivity to DNA damage and promotes mammary oncogenesis. Oncotarget 32 25909287
2017 Select human cancer mutants of NRMT1 alter its catalytic activity and decrease N-terminal trimethylation. Protein science : a publication of the Protein Society 25 28556566
2021 Age-related neurodegeneration and cognitive impairments of NRMT1 knockout mice are preceded by misregulation of RB and abnormal neural stem cell development. Cell death & disease 16 34711807
2021 CREB-mediated transcriptional activation of NRMT1 drives muscle differentiation. Transcription 12 34403304
2020 Selective Peptidomimetic Inhibitors of NTMT1/2: Rational Design, Synthesis, Characterization, and Crystallographic Studies. Journal of medicinal chemistry 12 32689795
2019 In vivo methylation of OLA1 revealed by activity-based target profiling of NTMT1. Chemical science 12 31857877
2018 The N-terminal methyltransferase homologs NRMT1 and NRMT2 exhibit novel regulation of activity through heterotrimer formation. Protein science : a publication of the Protein Society 12 30151928
2022 Knockdown of NRMT enhances sensitivity of retinoblastoma cells to cisplatin through upregulation of the CENPA/Myc/Bcl2 axis. Cell death discovery 11 35013138
2021 Chemoproteomic Study Uncovers HemK2/KMT9 As a New Target for NTMT1 Bisubstrate Inhibitors. ACS chemical biology 9 34192867
2023 Structure-Activity Relationship Studies of Venglustat on NTMT1 Inhibition. Journal of medicinal chemistry 8 36634151
2024 Characterizations of Protein Arginine Deiminase 1 as a Substrate of NTMT1: Implications of Nα-Methylation in Protein Stability and Interaction. Journal of proteome research 2 39287128
2023 Pan-cancer analysis reveals the pro-oncogenic role of N6-methyladenosine (m6A)-regulated NTMT1 in head and neck squamous cell carcinoma. Journal of biochemical and molecular toxicology 2 38014887

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