Affinage

FTSJ1

tRNA (cytidine(32)/guanosine(34)-2'-O)-methyltransferase · UniProt Q9UET6

Length
329 aa
Mass
36.1 kDa
Annotated
2026-04-28
29 papers in source corpus 13 papers cited in narrative 13 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

FTSJ1 is a conserved S-adenosylmethionine-dependent tRNA 2'-O-methyltransferase that modifies the anticodon loop of multiple cytoplasmic tRNAs at positions 32 (Nm32) and 34 (Nm34), functioning in distinct complexes with THADA (for Nm32) and WDR6 (for Nm34), where Nm34 methylation requires prior m1G37 modification, establishing a hierarchical interdependence among anticodon modifications (PMID:32558197, PMID:40483304). FTSJ1 contains a Rossmann-fold catalytic domain and engages its partner WD40-repeat proteins via its C-terminal region; structural studies of the yeast Trm7–Trm734 complex and the human FTSJ1–THADA complex define the substrate recognition mechanism, with the tRNA D-arm and anticodon loop anchored inside the partner protein scaffold (PMID:31586407, PMID:40483304). Loss of FTSJ1 selectively destabilizes tRNAPhe in the brain, causing ribosome pausing at Phe codons, reduced translation of synaptic organization genes, immature dendritic spine morphology, aberrant synaptic plasticity, and memory deficits in mice (PMID:33771871, PMID:36720500). Loss-of-function mutations in FTSJ1 cause nonsyndromic X-linked intellectual disability (PMID:15162322, PMID:15342698).

Mechanistic history

Synthesis pass · year-by-year structured walk · 10 steps
  1. 2004 High

    Identifying FTSJ1 as a disease gene resolved the molecular basis of nonsyndromic X-linked intellectual disability loci (MRX9 and others), establishing that a conserved RNA methyltransferase homolog is essential for normal cognitive development.

    Evidence Mutation screening and RT-PCR in multiple independent families with loss-of-function variants (splice, nonsense, frameshift)

    PMID:15162322 PMID:15342698

    Open questions at the time
    • Enzymatic substrate and modification type in human cells unknown
    • No animal model to confirm causality
  2. 2008 High

    Demonstrating that a splice-site mutation triggers nonsense-mediated mRNA decay established that FTSJ1 intellectual disability alleles act through complete loss of protein, not dominant-negative effects.

    Evidence Cycloheximide rescue of mutant transcript levels in patient lymphoblasts

    PMID:18081026

    Open questions at the time
    • Cellular consequence of FTSJ1 loss still unknown
    • No biochemical characterization of enzymatic activity
  3. 2015 High

    Identifying FTSJ1 as the enzyme responsible for 2'-O-methylation at C32 and G34 of tRNAPhe defined its molecular function and revealed that a patient missense variant (A26P) selectively abolishes Gm34, pinpointing the critical modification for disease.

    Evidence Mass spectrometry of tRNA modifications in patient-derived cell lines and yeast trm7 complementation

    PMID:26310293

    Open questions at the time
    • Partner proteins for position-specific methylation unidentified in human
    • Mechanism of substrate specificity unknown
  4. 2019 High

    Solving the crystal structure of the yeast Trm7–Trm734 complex revealed how the methyltransferase is positioned by a WD40-repeat scaffold and why the tRNA D-arm is required for C34 methylation, providing a structural framework for understanding patient mutations.

    Evidence X-ray crystallography, SAXS, in vitro methylation with tRNA truncations and site-directed mutagenesis

    PMID:31586407

    Open questions at the time
    • No human FTSJ1–WDR6 structure
    • Structural basis for Nm32 methylation and its partner unknown
  5. 2020 High

    Reconstituting FTSJ1–WDR6 complex activity in vitro and demonstrating hierarchical interdependence of modifications at positions 32, 34, and 37 established that Nm34 requires prior m1G37 and that FTSJ1 loss reduces UUU codon translation efficiency.

    Evidence Co-immunoprecipitation, in vitro reconstituted methyltransferase assay, codon-specific translation analysis in FTSJ1 KO cells

    PMID:32558197

    Open questions at the time
    • Partner for Nm32 methylation (THADA) not yet structurally characterized with FTSJ1
    • In vivo translational consequences in neuronal tissue not yet examined
  6. 2020 High

    Drosophila studies expanded the substrate repertoire to tRNAPhe, tRNATrp, and tRNALeu, and revealed that loss of FTSJ1 orthologs disrupts small RNA pathways and antiviral defense, broadening the functional impact beyond translation.

    Evidence Genetic knockout in Drosophila with MALDI-TOF MS, RiboMethSeq, and phenotypic analysis of small RNA pathways and viral sensitivity

    PMID:31943105

    Open questions at the time
    • Whether small RNA pathway involvement is conserved in mammals is untested
    • Mechanism linking tRNA methylation to small RNA silencing unclear
  7. 2021 High

    An Ftsj1 knockout mouse model mechanistically connected tRNA 2'-O-methylation to brain-specific tRNAPhe destabilization, ribosome pausing at Phe codons, reduced translation of synaptic genes, aberrant synaptic morphology and plasticity, and cognitive-behavioral deficits, providing a complete molecular-to-behavioral causal chain for FTSJ1-linked intellectual disability.

    Evidence Ftsj1 KO mouse with LC-MS/MS tRNA analysis, ribosome profiling, synaptic imaging, and behavioral assays

    PMID:33771871

    Open questions at the time
    • Why tRNAPhe is selectively destabilized in brain but not other tissues is unexplained
    • Whether restoring tRNAPhe or Nm modifications can rescue phenotypes untested
  8. 2022 Medium

    Identification of a conserved motif in Trm732/THADA required for Nm32 activity defined the molecular determinants of the FTSJ1 partner that directs position-32 methylation.

    Evidence Site-directed mutagenesis of Trm732/THADA with yeast complementation and tRNA modification assays

    PMID:35559166

    Open questions at the time
    • Structural basis of Trm732/THADA motif function unknown at this point
    • Single-lab finding awaits independent confirmation
  9. 2023 Medium

    FTSJ1 depletion in human neural progenitor cells recapitulated the neuronal morphology defects (long, thin spines) seen in animal models, demonstrating cell-autonomous effects in a human neuronal system.

    Evidence RiboMethSeq in patient cells, morphological imaging of differentiated neurons from FTSJ1-depleted human neural progenitors, cross-species validation in Drosophila

    PMID:36720500

    Open questions at the time
    • Electrophysiological consequences in human neurons not assessed
    • Whether specific tRNA destabilization drives spine defects in human cells untested
  10. 2025 High

    The cryo-EM structure of human FTSJ1–THADA with tRNA substrate revealed a distinct binding mode from FTSJ1–WDR6 and showed how THADA anchors the tRNA for Nm32 methylation, completing the structural picture of both FTSJ1 complexes.

    Evidence Cryo-EM at near-atomic resolution with biochemical mutagenesis validation

    PMID:40483304

    Open questions at the time
    • No structure of human FTSJ1–WDR6–tRNA ternary complex yet
    • How cells regulate the balance between Nm32 and Nm34 modification is unknown

Open questions

Synthesis pass · forward-looking unresolved questions
  • Key unresolved questions include why FTSJ1 loss selectively destabilizes tRNAPhe in the brain, whether therapeutic restoration of tRNAPhe or its modifications can rescue cognitive phenotypes, and whether FTSJ1's reported effects on small RNA pathways and cancer cell metabolism reflect conserved physiological roles.
  • Tissue-specific tRNA surveillance mechanism targeting unmodified tRNAPhe unknown
  • No therapeutic rescue experiments in vivo
  • Cancer and glycolysis links from single labs await independent replication

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0016740 transferase activity 7
Localization
GO:0005829 cytosol 3
Pathway
R-HSA-8953854 Metabolism of RNA 6 R-HSA-392499 Metabolism of proteins 2
Partners
THADAWDR6
Complex memberships
FTSJ1-THADA (Nm32 methyltransferase complex)FTSJ1-WDR6 (Nm34 methyltransferase complex)

Evidence

Reading pass · 13 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2004 FTSJ1 was identified as a homolog of E. coli RNA methyltransferase FtsJ/RrmJ, and loss-of-function mutations (splice defect, nonsense mutation, single-nucleotide deletion) cause nonsyndromic X-linked mental retardation, with patient cell lines showing complete absence or significant reduction of FTSJ1 transcripts. Mutation screening, direct sequencing, expression studies (RT-PCR) in patient cell lines American journal of human genetics High 15162322
2004 A splice site mutation in FTSJ1 (IVS3-2A>G) causes exon 4 skipping and introduces a premature stop codon, likely producing a severely truncated protein and linking FTSJ1 to X-linked mental retardation (MRX9 family). Direct sequencing, RT-PCR analysis of splice products in patient samples Journal of medical genetics High 15342698
2008 A splice donor mutation in FTSJ1 intron 8 (c.571+1G>A) causes intron retention, frameshift, and premature termination; mutant mRNA is degraded by nonsense-mediated mRNA decay (NMD), as demonstrated by cycloheximide rescue restoring transcript levels. Sequencing, RT-PCR, quantitative RT-PCR, cycloheximide (NMD inhibitor) treatment in patient lymphoblasts American journal of medical genetics. Part B, Neuropsychiatric genetics High 18081026
2015 FTSJ1 is the human ortholog of yeast Trm7 and is responsible for 2'-O-methylation at C32 (Cm32) and G34 (Gm34) in tRNAPhe anticodon loop; loss-of-function FTSJ1 patient cell lines nearly completely lack Cm32 and Gm34, and have reduced peroxywybutosine (o2yW37). A missense allele FTSJ1-p.A26P specifically abolishes Gm34 but not Cm32, implicating Gm34 as a critical modification. Mass spectrometry-based tRNA modification analysis of patient-derived cell lines; yeast trm7 mutant complementation; biochemical analysis of Trm734 binding Human mutation High 26310293
2019 Crystal structure of yeast Trm7 (FTSJ1 ortholog)-Trm734 complex reveals Trm7 has a Rossmann-fold catalytic domain, Trm734 has three WD40 β-propeller domains forming a V-shaped cleft that docks Trm7 via its C-terminal region. The D-arm of substrate tRNA is required for methylation at position 34. A point mutation in Trm7 equivalent to an FTSJ1 NSXLID patient mutation decreases methylation activity. X-ray crystallography, SAXS, in vitro methylation assays with tRNA transcript variants, site-directed mutagenesis Nucleic acids research High 31586407
2020 FTSJ1 interacts with WDR6 as a required partner protein; the FTSJ1-WDR6 complex reconstituted in vitro performs 2'-O-methylation at position 34 of specific tRNAs, with m1G37 as a prerequisite modification. Modifications at positions 32, 34, and 37 are interdependent and occur in a hierarchical order in vivo. Loss of FTSJ1 reduces translation efficiency of UUU (Phe) codons. Co-immunoprecipitation, in vitro reconstitution of methyltransferase activity, mass spectrometry of tRNA modifications, codon-specific translation assay in ftsj1 KO cells EMBO reports High 32558197
2020 Drosophila TRM7 orthologs CG7009 and CG5220 (functional orthologs of yeast TRM7/human FTSJ1) methylate specific tRNA anticodon positions; CG7009 methylates the wobble position 34 in tRNAPhe, tRNATrp, and tRNALeu, while CG5220 methylates position C32 in the same tRNAs and additional tRNAs. Loss of these enzymes disrupts small RNA silencing pathways and increases sensitivity to RNA virus infection. Genetic knockout, MALDI-TOF mass spectrometry, RiboMethSeq, phenotypic analysis (lifespan, small RNA pathway, viral sensitivity) Nucleic acids research High 31943105
2021 Mouse Ftsj1 is responsible for 2'-O-methylation of 11 species of cytosolic tRNAs at the anticodon region; Ftsj1 KO selectively reduces steady-state tRNAPhe levels in the brain, causing slow decoding at Phe codons (ribosome pausing). Ribosome profiling shows reduced translation efficiency of synaptic organization/function genes. Ftsj1 KO mice exhibit immature synaptic morphology, aberrant synaptic plasticity, anxiety-like behavior, and memory deficits. Ftsj1 KO mouse model, LC-MS/MS tRNA modification mapping, ribosome profiling, tRNA Northern blot, synaptic morphology imaging, behavioral assays Science advances High 33771871
2022 A conserved RRSAGLP motif in the DUF2428 domain of yeast Trm732 (human homolog THADA, the partner of FTSJ1 for Nm32 methylation) is required for tRNA 2'-O-methylation activity at position 32; Trm732 variants carrying mutations in this motif lose methylation activity in both yeast and human THADA. Site-directed mutagenesis of Trm732/THADA, in vivo yeast complementation, tRNA modification assays ACS omega Medium 35559166
2023 FTSJ1 regulates tRNA 2'-O-methylation at positions 32 and 34 of multiple tRNA species; loss of FTSJ1 in human neural progenitor cells results in long and thin spine neurites upon differentiation into neurons. The same morphological defects are observed in Drosophila FTSJ1 orthologs and are associated with long-term memory deficits. RiboMethSeq analysis of patient-derived blood cells, transcriptome analysis, differentiation of FTSJ1-depleted human neural progenitor cells into neurons (morphological imaging), Drosophila behavioral assays Life science alliance Medium 36720500
2025 Cryo-EM structure of the human FTSJ1-THADA complex with and without tRNA substrate reveals that FTSJ1 binds THADA via its C-terminal region through an interaction mode distinct from the FTSJ1-WDR6 complex. The tRNA substrate is anchored inside THADA, and key THADA residues for tRNA recognition were identified and validated biochemically; this complex mediates Nm32 modification of tRNAs. Cryo-electron microscopy, biochemical validation of key residues by mutagenesis Communications biology High 40483304
2020 FTSJ1 mediates 2'-O-methyladenosine (Am) modification of tRNAs; overexpression of FTSJ1 in NSCLC cells inhibits proliferation and migration and promotes apoptosis, while knockdown has the opposite effect. Mechanistically, FTSJ1 overexpression decreases DRAM1 expression, and DRAM1 silencing augments the antitumor effect of FTSJ1. Loss- and gain-of-function assays (cell proliferation, migration, apoptosis), HPLC/MS tRNA modification quantification, RNA-seq, rescue assays, in vivo xenograft Cell death & disease Medium 32393790
2024 PM2.5 suppresses FTSJ1 expression and Am tRNA modification; silencing of FTSJ1 increases PGK1 expression and translation, enhancing glycolytic metabolism (elevated lactate, pyruvate, ECAR) in NSCLC cells. Glycolytic inhibitor 2-DG reverses this effect. Knockdown/overexpression of FTSJ1, HPLC-MS tRNA modification analysis, glycolysis assays (ECAR, lactate, pyruvate), RNA-seq, polysome profiling (translation), xenograft Cell death & disease Medium 39695074

Source papers

Stage 0 corpus · 29 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2015 Defects in tRNA Anticodon Loop 2'-O-Methylation Are Implicated in Nonsyndromic X-Linked Intellectual Disability due to Mutations in FTSJ1. Human mutation 117 26310293
2004 Mutations in the FTSJ1 gene coding for a novel S-adenosylmethionine-binding protein cause nonsyndromic X-linked mental retardation. American journal of human genetics 115 15162322
2021 Loss of Ftsj1 perturbs codon-specific translation efficiency in the brain and is associated with X-linked intellectual disability. Science advances 59 33771871
2004 A splice site mutation in the methyltransferase gene FTSJ1 in Xp11.23 is associated with non-syndromic mental retardation in a large Belgian family (MRX9). Journal of medical genetics 57 15342698
2020 Intellectual disability-associated gene ftsj1 is responsible for 2'-O-methylation of specific tRNAs. EMBO reports 48 32558197
2015 Purification and identification of Bacillus subtilis SPB1 lipopeptide biosurfactant exhibiting antifungal activity against Rhizoctonia bataticola and Rhizoctonia solani. Environmental science and pollution research international 48 26645234
2008 A loss-of-function mutation in the FTSJ1 gene causes nonsyndromic X-linked mental retardation in a Japanese family. American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics 41 18081026
2007 Loss of SLC38A5 and FTSJ1 at Xp11.23 in three brothers with non-syndromic mental retardation due to a microdeletion in an unstable genomic region. Human genetics 40 17333282
2020 tRNA 2'-O-methylation by a duo of TRM7/FTSJ1 proteins modulates small RNA silencing in Drosophila. Nucleic acids research 38 31943105
2020 FTSJ1 regulates tRNA 2'-O-methyladenosine modification and suppresses the malignancy of NSCLC via inhibiting DRAM1 expression. Cell death & disease 37 32393790
2011 Phylogenetic lineage and pilus protein Spb1/SAN1518 affect opsonin-independent phagocytosis and intracellular survival of Group B Streptococcus. Microbes and infection 29 21238599
2011 The impact of the Bacillus subtilis SPB1 biosurfactant on the midgut histology of Spodoptera littoralis (Lepidoptera: Noctuidae) and determination of its putative receptor. Journal of invertebrate pathology 26 22079884
2015 Assessment of the antidiabetic and antilipidemic properties of Bacillus subtilis SPB1 biosurfactant in alloxan-induced diabetic rats. Biopolymers 24 26228442
2019 Structure of tRNA methyltransferase complex of Trm7 and Trm734 reveals a novel binding interface for tRNA recognition. Nucleic acids research 21 31586407
2018 A mouse model for intellectual disability caused by mutations in the X-linked 2'‑O‑methyltransferase Ftsj1 gene. Biochimica et biophysica acta. Molecular basis of disease 19 30557699
2023 Investigating the Inhibition of FTSJ1, a Tryptophan tRNA-Specific 2'-O-Methyltransferase by NV TRIDs, as a Mechanism of Readthrough in Nonsense Mutated CFTR. International journal of molecular sciences 14 37298560
2008 Positive association of the FTSJ1 gene polymorphisms with nonsyndromic X-linked mental retardation in young Chinese male subjects. Journal of human genetics 13 18401546
2008 Genetic variations in FTSJ1 influence cognitive ability in young males in the Chinese Han population. Journal of neurogenetics 12 19012053
2023 rRNA methylation by Spb1 regulates the GTPase activity of Nog2 during 60S ribosomal subunit assembly. Nature communications 11 36864048
2023 The ribose methylation enzyme FTSJ1 has a conserved role in neuron morphology and learning performance. Life science alliance 10 36720500
2016 Evaluation of Bacillus subtilis SPB1 biosurfactant effects on hyperglycemia, angiotensin I-converting enzyme (ACE) activity and kidney function in rats fed on high-fat-high-fructose diet. Archives of physiology and biochemistry 9 28019119
2023 Enhanced biosurfactant production by Bacillus subtilis SPB1 using developed fed-batch fermentation: effects of glucose levels and feeding systems. Bioprocess and biosystems engineering 7 36645491
2022 Identification of a Trm732 Motif Required for 2'-O-methylation of the tRNA Anticodon Loop by Trm7. ACS omega 7 35559166
2024 Triple-Negative Breast Cancer Intrinsic FTSJ1 Favors Tumor Progression and Attenuates CD8+ T Cell Infiltration. Cancers 6 38339348
2024 Downregulation of tRNA methyltransferase FTSJ1 by PM2.5 promotes glycolysis and malignancy of NSCLC via facilitating PGK1 expression and translation. Cell death & disease 3 39695074
2001 A Saccharomyces servazzii clone homologous to Saccharomyces cerevisiae chromosome III spanning KAR4, ARS 304 and SPB1 lacks the recombination enhancer but contains an unknown ORF. Yeast (Chichester, England) 3 11427961
2020 Correction: FTSJ1 regulates tRNA 2'-O-methyladenosine modification and suppresses the malignancy of NSCLC via inhibiting DRAM1 expression. Cell death & disease 2 32488007
2025 Structural insights into tRNA recognition of the human FTSJ1-THADA complex. Communications biology 1 40483304
2026 FTSJ1-mediated IL1RN mRNA instability promotes inflammation-driven hepatocellular carcinoma. Journal of gastrointestinal oncology 0 41816574