Affinage

PUS10

tRNA pseudouridine synthase Pus10 · UniProt Q3MIT2

Length
529 aa
Mass
60.2 kDa
Annotated
2026-06-10
13 papers in source corpus 11 papers cited in narrative 11 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

PUS10 is a bifunctional pseudouridine synthase that modifies tRNA and, independently of catalysis, controls small RNA biogenesis and apoptotic signaling (PMID:23743107, PMID:31819270). Its catalytic domain adopts the canonical pseudouridine synthase fold paired with a unique N-terminal THUMP-containing domain that contributes to tRNA binding, with substrate uridines flipped into a basic active-site cleft by an induced-fit mechanism (PMID:17900615, PMID:23743107). Biochemically, PUS10 generates pseudouridine at tRNA positions Ψ54 and Ψ55 through two distinct uridine-recognition mechanisms, with Ψ54 formation in tRNAs such as the HIV primer tRNALys3 requiring a defined GUUCAm1AAUC recognition sequence (PMID:23898217, PMID:30530625). In mammals this activity is compartmentalized: the cytoplasmic isoform performs Ψ54/Ψ55 modification, while a catalytically inactive nuclear isoform binds unmodified U54U55 tRNAs and blocks their premature modification by TRUB1, ensuring Ψ54Ψ55-containing tRNAs are modified exclusively in the cytoplasm (PMID:30530625, PMID:33023933). Beyond modification, PUS10 directly binds pri-miRNAs and interacts with the DROSHA-DGCR8 microprocessor to promote miRNA maturation in a catalysis-independent manner, including maturation of miR-194-5p that suppresses renal cell carcinoma migration via a NUDC/Cofilin1 axis (PMID:31819270, PMID:37596681). PUS10-dependent tRNA-derived small RNAs restrain innate immunity, as loss of Pus10 perturbs tdR pools and retroelement expression to drive accumulation of RNA-DNA hybrids that activate the cGAS-STING interferon pathway (PMID:40402745). During TRAIL-induced apoptosis, PUS10 translocates from nucleus to mitochondria via CRM1-dependent export and amplifies caspase-3 activity through the intrinsic pathway (PMID:28981101).

Mechanistic history

Synthesis pass · year-by-year structured walk · 10 steps
  1. 2007 High

    Established the structural basis of PUS10 catalysis by resolving its two-domain architecture and active-site residues, defining how it engages RNA substrates.

    Evidence X-ray crystallography of human PUS10 at 2.0 Å with structural superposition and electrostatic modeling

    PMID:17900615

    Open questions at the time
    • No RNA-bound structure
    • Catalytic mechanism inferred by homology rather than directly observed
    • Function of THUMP domain not tested structurally with substrate
  2. 2008 High

    Defined PUS10 (archaeal) as a dual-specificity enzyme producing both Ψ54 and Ψ55 with substrate requirements distinct from bacterial/yeast Ψ55 synthases.

    Evidence In vitro pseudouridine synthase assays with two archaeal orthologs and nearest-neighbor analysis

    PMID:18952823

    Open questions at the time
    • Archaeal not human enzyme
    • In vivo substrate scope not defined
    • Independence of the two activities mechanistically unexplained
  3. 2012 High

    Placed Pus10 in a sequential tRNA modification pathway by showing it initiates m1Ψ54 formation that is completed by TrmY methylation.

    Evidence In vitro reconstitution with purified Pus10 and TrmY plus in vivo gene deletion in Haloferax volcanii

    PMID:22274953

    Open questions at the time
    • Archaeal pathway; human relevance untested
    • Whether human PUS10 participates in a comparable downstream methylation step unknown
  4. 2013 High

    Resolved the kinetics and the residue determinants of uridine flipping and substrate binding, supporting an induced-fit catalytic model with separable Ψ54 vs Ψ55 recognition.

    Evidence Kinetic and fluorescence binding assays with site-directed mutagenesis of archaeal Pus10 and homology models from the human structure

    PMID:23743107 PMID:23898217

    Open questions at the time
    • Mechanistic residues mapped in archaeal enzyme
    • Human active-site residues not individually validated
    • Structural basis of dual recognition not directly visualized
  5. 2017 Medium

    Revealed a non-modification role for PUS10 in apoptosis, showing CRM1-dependent nuclear-to-mitochondrial relocation that amplifies caspase-3 activity.

    Evidence Immunofluorescence, leptomycin B and caspase-3 inhibition, immunoblotting across TRAIL-sensitive and -resistant cell lines

    PMID:28981101

    Open questions at the time
    • Molecular target of PUS10 at mitochondria unknown
    • Single lab
    • Link between modification activity and apoptotic role unclear
  6. 2018 High

    Demonstrated human cytoplasmic PUS10 generates Ψ54 in specific tRNAs via a defined sequence context, distinguishing it from the nuclear form.

    Evidence In vitro assays with recombinant human PUS10, nearest-neighbor analysis, and subcellular fractionation

    PMID:30530625

    Open questions at the time
    • Full cellular tRNA target set not defined
    • Functional consequence of Ψ54 on primer tRNAs not measured
  7. 2019 High

    Uncovered a catalysis-independent function in miRNA biogenesis, linking PUS10 to the microprocessor and pri-miRNA processing.

    Evidence RIP, reciprocal Co-IP with DROSHA/DGCR8, siRNA knockdown, catalytic mutant, and Ψ-seq across cell lines

    PMID:31819270

    Open questions at the time
    • How PUS10 selects pri-miRNAs unknown
    • Structural basis of microprocessor interaction undefined
    • Relative contribution of nuclear vs cytoplasmic isoform unclear
  8. 2020 High

    Explained spatial control of tRNA modification, showing the inactive nuclear isoform sequesters unmodified tRNAs to gate cytoplasmic PUS10 activity against TRUB1.

    Evidence Nearest-neighbor analysis with recombinant proteins and extracts, Ψ55 synthase knockdown, and RNA binding assays

    PMID:33023933

    Open questions at the time
    • Mechanism generating two isoforms not detailed
    • Physiological consequence of gating not tested in vivo
  9. 2023 Medium

    Connected PUS10 miRNA function to disease by defining a PUS10/miR-194-5p/NUDC/Cofilin1 axis suppressing RCC migration and its repression by HIF-1A.

    Evidence RIP, luciferase, ChIP, migration assays, in vivo metastasis model, and catalytic mutant in renal carcinoma cells

    PMID:37596681

    Open questions at the time
    • Single cancer context
    • Generality of the axis untested
    • Direct HIF-1A binding to PUS10 promoter not structurally resolved
  10. 2025 Medium

    Tied PUS10-dependent tRNA-derived small RNAs to innate immune restraint, showing Pus10 loss activates cGAS-STING via RNA-DNA hybrid accumulation.

    Evidence Pus10 knockout mouse with tdR profiling, retroelement and RNA-DNA hybrid analysis, and tdR supplementation rescue

    PMID:40402745

    Open questions at the time
    • Identity of effector tdRs incompletely defined
    • Partial rescue only
    • Mechanistic link from tRNA modification to tdR pools not fully resolved

Open questions

Synthesis pass · forward-looking unresolved questions
  • How PUS10's catalytic tRNA modification, catalysis-independent miRNA processing, immune regulation, and apoptotic relocation are mechanistically coordinated within one protein remains unresolved.
  • No structure of human PUS10 bound to pri-miRNA or microprocessor
  • Mitochondrial caspase-3 target unidentified
  • Switch controlling isoform-specific functions unknown

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0140098 catalytic activity, acting on RNA 4 GO:0003723 RNA binding 3 GO:0016853 isomerase activity 3
Localization
GO:0005634 nucleus 3 GO:0005829 cytosol 2 GO:0005739 mitochondrion 1
Pathway
R-HSA-8953854 Metabolism of RNA 3 R-HSA-168256 Immune System 1 R-HSA-5357801 Programmed Cell Death 1
Partners

Evidence

Reading pass · 11 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2007 Crystal structure of human PUS10 solved at 2.0 Å resolution, revealing a crescent-shaped molecule with two domains: a conserved pseudouridine synthase catalytic domain and a unique N-terminal THUMP-containing domain. Superposition with other Psi synthase catalytic domains identified a conserved active-site residue set, indicating PUS10 employs a similar catalytic mechanism. The active site is in a deep basic cleft with flexible thumb and forefinger loops proposed to stabilize RNA substrate binding. X-ray crystallography at 2.0 Å resolution; structural superposition; electrostatic modeling Journal of molecular biology High 17900615
2008 Archaeal Pus10 (Methanocaldococcus jannaschii and Pyrococcus furiosus) functions as both a tRNA Ψ54 and Ψ55 synthase in vitro; the two modifications occur independently and show salt-concentration-dependent variation. Unlike bacterial TruB and yeast Pus4, archaeal Pus10 does not require a U54×A58 reverse Hoogsteen base pair or pyrimidine at position 56 for Ψ55 production. In vitro pseudouridine synthase assay with recombinant archaeal Pus10 proteins; nearest-neighbor analysis RNA (New York, N.Y.) High 18952823
2012 Archaeal Pus10 and the COG1901/TrmY methyltransferase act sequentially in vitro to produce 1-methylpseudouridine (m1Ψ) at position 54 of tRNA: Pus10 first converts U54 to Ψ54, then TrmY methylates Ψ54 in an AdoMet-dependent reaction. Efficient methylation by TrmY requires Ψ55 at position 55; C55 allows only inefficient methylation and a purine at 55 blocks it entirely. In vitro reconstitution with purified recombinant Pus10 (M. jannaschii) and TrmY enzymes; tRNA/TΨ-arm substrates; in vivo deletion of COG1901 gene in Haloferax volcanii with complementation RNA (New York, N.Y.) High 22274953
2013 Quantitative biochemical analysis of P. furiosus Pus10 showed high affinity for substrate and product tRNA (Kd ~30 nM), with Km ~400 nM and kcat ~0.9 s⁻¹ for Ψ55 formation. Site-directed mutagenesis of the thumb loop reduced catalytic efficiency, and a new catalytic arginine (Arg208) was identified as likely responsible for flipping the target uridine into the active site. The N-terminal THUMP-containing domain contributes to tRNA binding. Data support an induced-fit binding mechanism. In vitro pseudouridine synthase assay; fluorescence binding assay; site-directed mutagenesis Journal of molecular biology High 23743107
2013 Using homology models based on human PUS10 crystal structure and site-directed mutagenesis of archaeal Pus10, the forefinger loop, a specific Arg, and a Tyr residue were identified as critical for Ψ54 but not Ψ55 synthase activity. A conserved Leu residue, in addition to the catalytic Asp, is essential for both activities. These findings indicate archaeal Pus10 uses two distinct substrate-uridine recognition mechanisms for Ψ54 vs. Ψ55 that share some common features. Homology modeling; site-directed mutagenesis; in vitro pseudouridine synthase assay RNA (New York, N.Y.) High 23898217
2017 Human PUS10 is predominantly nuclear but translocates to mitochondria early during TRAIL-induced apoptosis via CRM1-mediated nuclear export, concurrent with cytochrome c and SMAC release. Caspase-3 is required for PUS10 translocation; conversely, PUS10 translocation to mitochondria reciprocally amplifies caspase-3 activity through the intrinsic/mitochondrial pathway, creating a feedback amplification loop. p53 is not involved in TRAIL-induced PUS10 movement. Immunofluorescence; immunoblotting; CRM1 inhibitor (leptomycin B); caspase-3 inhibition; apoptosis indicators across multiple TRAIL-sensitive and resistant cell lines Cell death & disease Medium 28981101
2018 Human PUS10 produces Ψ54 in select tRNAs including tRNALys3 (the HIV reverse transcriptase primer). This activity is restricted to the cytoplasmic isoform; nuclear PUS10 does not have this activity. The recognition sequence GUUCAm1AAUC (positions 53–61, containing 1-methyladenosine) combined with a stable acceptor stem is required for maximum Ψ54 synthase activity. Recombinant human PUS10 can also generate Ψ55 in tRNAs lacking the Ψ54 recognition sequence. In vitro pseudouridine synthase assay with recombinant human Pus10 (SF9-derived); nearest-neighbor analysis; subcellular fractionation RNA (New York, N.Y.) High 30530625
2019 Human PUS10 directly binds pri-miRNAs and physically interacts with the microprocessor complex (DROSHA-DGCR8), promoting miRNA biogenesis in the nucleus. Depletion of PUS10 causes accumulation of unprocessed pri-miRNAs and reduction of mature miRNAs. This function is independent of PUS10's catalytic pseudouridine synthase activity. Additionally, PUS10 produces pseudouridines at specific positions in cytoplasmic tRNAs (profiled by sequencing). RNA immunoprecipitation; Co-immunoprecipitation with DROSHA/DGCR8; siRNA knockdown; pri-miRNA/mature miRNA quantification; Ψ-seq tRNA profiling; catalytic mutant analysis Nature chemical biology High 31819270
2020 Mammalian cytoplasmic PUS10 produces both Ψ54 and Ψ55 in tRNAs containing Ψ54Ψ55 (including retroviral primer tRNAs), whereas nuclear TRUB1 produces Ψ55 in most elongator tRNAs and mitochondrial TRUB2 acts on mitochondrial tRNAs. The nuclear isoform of PUS10 is catalytically inactive and specifically binds unmodified U54U55 versions of Ψ54Ψ55-containing tRNAs as well as A54U55 tRNAiMet, inhibiting TRUB1-mediated U55→Ψ55 conversion in the nucleus. This compartmentalization ensures that Ψ54Ψ55-containing tRNAs are modified exclusively by cytoplasmic PUS10. Nearest-neighbor analysis with recombinant proteins and subcellular extracts; specific Ψ55 synthase knockdown cells; RNA binding assays with nuclear PUS10 isoform RNA (New York, N.Y.) High 33023933
2023 PUS10 promotes the maturation of miR-194-5p in renal cell carcinoma cells, suppressing RCC migration via a PUS10/miR-194-5p/NUDC/Cofilin1 axis. This function is independent of PUS10's classical pseudouridine catalytic activity. HIF-1A transcriptionally represses PUS10 under hypoxic conditions. RNA immunoprecipitation; dual luciferase reporter assay; chromatin immunoprecipitation; transwell/wound-healing assay; in vivo metastasis model; catalytic mutant analysis; microRNA sequencing Cell & bioscience Medium 37596681
2025 Loss of Pus10 in knockout mice causes cell-intrinsic upregulation of interferon signaling. Mechanistically, Pus10 loss alters the abundance of tRNA-derived small RNAs (tdRs), perturbing translation and endogenous retroelement expression, which promotes accumulation of proinflammatory RNA-DNA hybrids that activate the cGAS-STING pathway. Supplementation with specific tdR pools partly rescues these effects by interacting with RNA processing factors that modulate immune responses. Pus10 knockout mouse; IFN signaling readouts; tRNA-derived small RNA profiling; retroelement expression analysis; RNA-DNA hybrid detection; tdR supplementation rescue experiments Cell reports Medium 40402745

Source papers

Stage 0 corpus · 13 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2019 Differential roles of human PUS10 in miRNA processing and tRNA pseudouridylation. Nature chemical biology 99 31819270
2007 Crystal structure of human Pus10, a novel pseudouridine synthase. Journal of molecular biology 73 17900615
2008 Archaeal Pus10 proteins can produce both pseudouridine 54 and 55 in tRNA. RNA (New York, N.Y.) 48 18952823
2017 Reciprocal amplification of caspase-3 activity by nuclear export of a putative human RNA-modifying protein, PUS10 during TRAIL-induced apoptosis. Cell death & disease 47 28981101
2012 The archaeal COG1901/DUF358 SPOUT-methyltransferase members, together with pseudouridine synthase Pus10, catalyze the formation of 1-methylpseudouridine at position 54 of tRNA. RNA (New York, N.Y.) 37 22274953
2020 Mammalian nuclear TRUB1, mitochondrial TRUB2, and cytoplasmic PUS10 produce conserved pseudouridine 55 in different sets of tRNA. RNA (New York, N.Y.) 33 33023933
2018 The human ortholog of archaeal Pus10 produces pseudouridine 54 in select tRNAs where its recognition sequence contains a modified residue. RNA (New York, N.Y.) 24 30530625
2013 tRNA binding, positioning, and modification by the pseudouridine synthase Pus10. Journal of molecular biology 24 23743107
2018 Evolution of Eukaryal and Archaeal Pseudouridine Synthase Pus10. Journal of molecular evolution 21 29349599
2013 Role of forefinger and thumb loops in production of Ψ54 and Ψ55 in tRNAs by archaeal Pus10. RNA (New York, N.Y.) 16 23898217
2023 HIF1A-repressed PUS10 regulates NUDC/Cofilin1 dependent renal cell carcinoma migration by promoting the maturation of miR-194-5p. Cell & bioscience 8 37596681
2023 The alphaherpesvirus conserved pUS10 is important for natural infection and its expression is regulated by the conserved Herpesviridae protein kinase (CHPK). PLoS pathogens 4 36749787
2025 PUS10-induced tRNA fragmentation impacts retrotransposon-driven inflammation. Cell reports 3 40402745

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