Affinage

SPRTN

DNA-dependent metalloprotease SPRTN · UniProt Q9H040

Length
489 aa
Mass
55.1 kDa
Annotated
2026-06-10
66 papers in source corpus 37 papers cited in narrative 33 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 8/8 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

SPRTN (DVC1/Spartan) is a DNA-dependent zinc metalloprotease that serves as the central enzyme for DNA-protein crosslink (DPC) repair, cleaving diverse DNA-bound proteins during S-phase to relieve replication stress and maintain genome integrity (PMID:27871366, PMID:27871365, PMID:27852435, PMID:28053116). It is recruited to stalled forks and damage sites through a modular set of interfaces: a PIP box that engages PCNA via a distinctive YF-type interaction (PMID:27084448), a UBZ ubiquitin-binding domain (PMID:22681887, PMID:22987070, PMID:22902628, PMID:22894931), a SHP box that recruits the p97/VCP segregase (PMID:23042605, PMID:23042607), and a Nudix homology domain that binds PARP1-generated PAR (PMID:41542513). Substrate recognition is structure-specific: SPRTN cleaves proteins crosslinked at or adjacent to disruptions in duplex DNA such as ssDNA-dsDNA junctions, exploiting a bipartite DNA-binding strategy whereby DNA engagement through a Zn2+-binding sub-domain (ZBD) that normally shields the active-site metalloprotease sub-domain (MPD) switches the enzyme from an autoinhibited to an active state (PMID:30893605, PMID:32853547, PMID:27871365). DPC polyubiquitylation is the key specificity signal, sensed by a ubiquitin interface within the SprT catalytic region (USD) and a separate allosteric site on the protease domain that together drive an open, active conformation (PMID:40685547, PMID:40691134). Beyond replication-coupled repair, SPRTN also acts in replication-independent global-genome DPC repair downstream of SUMO-targeted ubiquitylation (PMID:36681662), and its proteolytic resection of adducts is the upstream step that licenses downstream DNA repair signaling and the action of TDP1 (PMID:36718861, PMID:37788708). Activity is governed by a ubiquitin switch in which monoubiquitylation triggers autocatalytic self-cleavage and proteasomal turnover, antagonized by the deubiquitinases VCPIP1, USP7, and USP11 and coordinated with ATM/ATR-driven acetylation, and by a reciprocal cross-activation loop with CHK1 kinase (PMID:33348378, PMID:32649882, PMID:33567341). SPRTN cooperates with p97/Ufd1-Npl4, which unfolds tightly folded ubiquitylated DPCs to make them accessible for cleavage (PMID:35469923), and with TEX264 in TOP1cc repair (PMID:32152270). Biallelic SPRTN mutations cause Ruijs-Aalfs syndrome, a progeroid disorder with genomic instability and early-onset hepatocellular carcinoma, and mouse models link DPC repair deficiency directly to spontaneous liver tumorigenesis (PMID:25261934, PMID:28199696).

Mechanistic history

Synthesis pass · year-by-year structured walk · 13 steps
  1. 2012 High

    Establishing how a previously uncharacterized factor coordinates replication stress responses, SPRTN was identified as a reader of monoubiquitylated PCNA that recruits the p97/VCP segregase to stalled forks and regulates translesion synthesis polymerase access.

    Evidence Co-IP, laser micro-irradiation, in vitro ubiquitylated-PCNA binding, and domain mutagenesis (UBZ, PIP, SHP boxes) across multiple labs

    PMID:22681887 PMID:22894931 PMID:22902628 PMID:22987070 PMID:23042605 PMID:23042607

    Open questions at the time
    • No protease/enzymatic activity was yet attributed to SPRTN
    • Direct substrates of SPRTN unknown
    • Mechanism of how p97 recruitment resolves stalled forks not defined
  2. 2012 Medium

    Linking SPRTN to mutagenesis control, the SprT domain was shown to interact with POLD3 and to protect ubiquitylated PCNA from USP1, embedding SPRTN in the RAD18-dependent damage tolerance machinery.

    Evidence Co-IP, siRNA knockdown with mutagenesis and SCE readouts, domain mutagenesis

    PMID:22987070 PMID:23254330

    Open questions at the time
    • Whether SprT-POLD3 interaction is catalytic was not resolved
    • No reconstitution of the regulatory effect on PCNA ubiquitylation
  3. 2014 High

    Demonstrating physiological essentiality, loss-of-function studies established SPRTN as required to suppress replication stress and showed that its biallelic mutation causes a human progeroid cancer-predisposition syndrome.

    Evidence Patient cell characterization, conditional knockout mice, DNA fiber assays, flow cytometry, and Drosophila ortholog analysis

    PMID:25242033 PMID:25261934 PMID:25501849

    Open questions at the time
    • The molecular substrate driving replication stress was not yet identified
    • Mechanistic basis of tissue-specific (liver) tumorigenesis unexplained
  4. 2016 High

    Defining SPRTN's core biochemical activity, purified SPRTN was shown to be a DNA-dependent metalloprotease that cleaves DNA-bound proteins, with structural and biochemical work revealing DNA-switch, ubiquitin-switch, and autocleavage regulatory mechanisms and a PCNA-independent DNA-binding requirement.

    Evidence In vitro protease assays with purified SPRTN, Xenopus extracts, PCNA-PIP crystal structure, DNA-binding mutagenesis, replicated across concurrent papers

    PMID:27084448 PMID:27838458 PMID:27852435 PMID:27871365 PMID:27871366

    Open questions at the time
    • Structural basis for DNA-dependent activation not yet solved
    • Full spectrum of physiological DPC substrates undefined
  5. 2017 High

    Confirming the in vivo repair function and its tumor-suppressive consequence, SPRTN was shown to drive direct DPC removal epistatic to RAD6-RAD18, with deficiency causing TOP1-DPC accumulation and liver tumors in mice.

    Evidence In vitro protease assays, comet and fiber assays, genetic epistasis, RADAR DPC isolation in hypomorphic mouse livers

    PMID:28053116 PMID:28199696

    Open questions at the time
    • Why TOP1-DPCs accumulate specifically in liver remained unexplained
    • Relationship between replication-coupled and other repair routes not yet mapped
  6. 2018 High

    Resolving how DPC proteolysis is partitioned, reconstitution showed SPRTN and the proteasome act as two independent DPC proteases — SPRTN activated by nascent-strand extension/polymerase stalling rather than polyubiquitylation in this context.

    Evidence Xenopus egg extract replication system with defined DPC substrates, proteasome inhibition, SPRTN immunodepletion, nascent strand analysis

    PMID:30595436

    Open questions at the time
    • Apparent independence from polyubiquitylation here contrasts with later ubiquitin-activation findings
    • Substrate handoff between the two proteases not defined
  7. 2019 High

    Providing atomic-level mechanism, the SprT-ssDNA structure revealed a ZBD that shields the MPD active site and an ssDNA-binding pocket required for protease activity, while a CHK1 cross-activation loop and a GCNA-TOP2 axis broadened SPRTN's regulatory and substrate landscape.

    Evidence X-ray crystallography with mutagenesis, in vitro CHK1 cleavage/phosphorylation assays, Co-IP and genetic hypersensitivity in mice and C. elegans

    PMID:30893605 PMID:31316063 PMID:31839538

    Open questions at the time
    • How DNA binding mechanically relieves ZBD autoinhibition not yet shown
    • Physiological scope of CHK1 cleavage unclear
  8. 2020 High

    Detailing substrate accessibility and recruitment control, work established structure-specific cleavage at dsDNA disruptions, the TEX264-p97-SPRTN axis for TOP1cc repair, and an ATM/ATR-VCPIP1 deubiquitination-then-acetylation cascade controlling SPRTN chromatin relocalization.

    Evidence In vitro protease assays with defined substrates, NMR, Co-IP, PLA, in vitro deubiquitination, PTM assays, and VCPIP1 knockout mice

    PMID:32152270 PMID:32649882 PMID:32853547

    Open questions at the time
    • Ordering of multiple recruiters at a single DPC not defined
    • How acetylation alters SPRTN activity mechanistically unresolved
  9. 2021 Medium

    Mapping the ubiquitin/SUMO logic and additional substrates, studies defined a self-cleavage ubiquitin switch antagonized by USP7 and USP11, SUMO-channeling toward proteolysis, MRE11 and CHK1 as cleavage targets, and a PARP-trapping repair role.

    Evidence In vitro ubiquitylation/deubiquitination and protease assays, MS cleavage-site mapping, HR reporter and clonogenic assays, knockout cells, chromatin fractionation

    PMID:33348378 PMID:33558481 PMID:33567341 PMID:34551432 PMID:34879279

    Open questions at the time
    • E3 ligase generating SPRTN monoubiquitylation not identified
    • Physiological significance of MRE11 cleavage under normal conditions unclear
  10. 2022 High

    Explaining how tightly folded crosslinked proteins are made cleavable, reconstitution showed p97/Ufd1-Npl4 unfolds polyubiquitinated DPC substrates to enable subsequent SPRTN proteolysis.

    Evidence Fully reconstituted in vitro system with purified p97, Ufd1-Npl4, SPRTN and an Eos-DPC reporter substrate

    PMID:35469923

    Open questions at the time
    • Coupling of p97 unfolding to SPRTN cleavage timing in cells not directly shown
  11. 2023 Medium

    Extending SPRTN beyond the replication fork, studies revealed replication-independent global-genome DPC repair requiring SUMO-targeted ubiquitylation and established proteolytic resection by SPRTN as the obligatory upstream step for downstream signaling and TDP1-mediated peptide removal.

    Evidence PxP and STAR DPC purification assays, patient variant cell lines, SUMO/ubiquitin inhibitors, SPRTN/TDP1 mutant zebrafish and human cells

    PMID:36681662 PMID:36718861 PMID:37788708

    Open questions at the time
    • How global-genome detection occurs without replication is incompletely defined
    • Division of labor among downstream peptidases not fully resolved
  12. 2025 High

    Defining the molecular basis of substrate-specific activation, two structural-biochemical studies showed polyubiquitin is the key specificity signal — sensed by a newly identified USD ubiquitin interface and an allosteric protease-domain site that together drive SPRTN into an open, active conformation.

    Evidence NMR spectroscopy, MD simulations, AlphaFold prediction, biophysical binding and quantitative in vitro protease assays with poly-Ub vs unmodified DPCs, mutagenesis and cellular validation

    PMID:40685547 PMID:40691134

    Open questions at the time
    • Integration of ubiquitin allostery with DNA-switch activation in vivo not fully resolved
    • Relationship between USD and the separate allosteric site unclear
  13. 2026 Medium

    Refining recruitment and the activation conformational cycle, work identified a PAR-binding NHD recruiting SPRTN downstream of PARP1, and showed that DNA relieves ZBD-mediated MPD autoinhibition with the autocleaved N-terminal fragment remaining catalytically active.

    Evidence Single-molecule analysis and in vitro PAR-binding assays (preprint); FRET-based protease assays and domain-deletion mutagenesis (preprint)

    PMID:41542513 PMID:42094449

    Open questions at the time
    • Both findings are preprints awaiting peer review
    • Functional weight of NHD versus UBZ/USD recruitment routes in cells undefined
    • In vivo consequence of an active autocleaved fragment not established

Open questions

Synthesis pass · forward-looking unresolved questions
  • How the multiple recruitment signals (PCNA, ubiquitin via UBZ/USD, PAR via NHD), the DNA conformational switch, and the ubiquitin allosteric switch are integrated in time and space at a single DPC to set substrate choice and cleavage timing remains unresolved.
  • No unified structural model of fully recruited, DNA- and ubiquitin-engaged active SPRTN
  • E3 ligase for SPRTN monoubiquitylation unidentified
  • Basis of tissue-specific pathology not mechanistically explained

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0140096 catalytic activity, acting on a protein 7 GO:0003677 DNA binding 3 GO:0016787 hydrolase activity 3
Localization
GO:0005634 nucleus 4 GO:0000228 nuclear chromosome 2
Pathway
R-HSA-73894 DNA Repair 4 R-HSA-69306 DNA Replication 3 R-HSA-1643685 Disease 2 R-HSA-392499 Metabolism of proteins 2
Partners
CHK1PARP1PCNAPOLD3TEX264USP7VCPVCPIP1
Complex memberships
SPRTN-p97/VCP-Ufd1-Npl4TEX264-p97-SPRTN

Evidence

Reading pass · 33 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2012 SPRTN (DVC1/Spartan/C1orf124) recruits the p97/VCP ubiquitin-selective chaperone to stalled replication forks via a conserved SHP box domain, and accumulates at replication stress sites requiring its UBZ ubiquitin-binding domain and PIP box PCNA-interacting motif. This DVC1-p97 axis is proposed to facilitate p97-dependent removal of TLS polymerase η from monoubiquitylated PCNA. Co-immunoprecipitation, laser micro-irradiation with live imaging, siRNA knockdown, domain mutagenesis (UBZ, PIP box, SHP box mutants), C. elegans genetic knockdown Nature structural & molecular biology High 23042605 23042607
2012 Spartan specifically recognizes monoubiquitylated PCNA via both its PIP box and UBZ domain in vitro, and is recruited to UV damage sites in a PCNA ubiquitylation-dependent manner. As a 'reader' of ubiquitylated PCNA, Spartan promotes a feed-forward loop: its knockdown compromises Rad18 chromatin association, PCNA monoubiquitylation, and Pol η localization to UV damage. In vitro ubiquitylated PCNA binding assays, co-immunoprecipitation, siRNA knockdown, immunofluorescence, UV-damage focus formation assays, domain mutagenesis Molecular cell High 22681887 22894931 22902628 22987070
2012 SPRTN's SprT putative zinc metalloprotease domain directly interacts with POLD3 (accessory subunit of replicative DNA polymerase Pol δ) and contributes to suppression of damage-induced mutagenesis by negatively regulating POLD3 function in Rev1/Pol ζ-dependent error-prone TLS. Co-immunoprecipitation, siRNA knockdown with mutagenesis readout, domain mutagenesis of SprT domain Nucleic acids research Medium 23254330
2012 Spartan protects against PCNA deubiquitylation by USP1 by preferentially associating with ubiquitin-modified PCNA, thereby maintaining elevated cellular levels of ubiquitylated PCNA and facilitating TLS polymerase access to stalled replication forks. Immunoprecipitation, siRNA knockdown, sister chromatid exchange assay, UV sensitivity assays Nucleic acids research Medium 22987070
2014 SPRTN is essential for preventing DNA replication stress during general DNA replication and for replication-related G2/M-checkpoint regulation in vivo. Biallelic germline mutations cause a progeroid syndrome with genomic instability and early-onset hepatocellular carcinoma (Ruijs-Aalfs syndrome). Patient cell characterization, in vitro replication assays, flow cytometry, DNA fiber assay, immunofluorescence, siRNA knockdown Nature genetics High 25261934
2014 Complete loss of Spartan causes early embryonic lethality in mice, while hypomorphic mice with reduced Spartan develop progeroid features including cataracts, lordokyphosis and cachexia. Cre-mediated conditional depletion causes impaired lesion bypass, incomplete DNA replication, micronuclei, chromatin bridges and cell death. Conditional knockout mouse model, Cre-mediated depletion, DNA fiber assay, flow cytometry, immunofluorescence, chromosome spreads Nature communications High 25501849
2014 The Drosophila Spartan ortholog maternal haploid (MH) accumulates in the male pronucleus before the first S phase, recruits p97/TER94 segregase to stalled replication forks, and is required to maintain paternal DNA integrity during nuclear decondensation at fertilization. Immunofluorescence localization in zygotes, genetic analysis of maternal-effect mutant, UV sensitivity assays in somatic cells Current biology : CB Medium 25242033
2016 SPRTN is a DNA-dependent metalloprotease that cleaves diverse DNA-binding proteins (DPC substrates) during S-phase progression. It requires DNA binding for protease activation and its activity is replication-coupled. RJALS patient cells with SPRTN mutations show defective DPC repair and hypersensitivity to DPC-inducing agents due to impaired replication fork progression. In vitro protease assays with purified SPRTN, DNA fiber assay, DPC isolation assay, patient-derived cell characterization, siRNA knockdown, immunofluorescence Molecular cell High 27852435 27871365 27871366
2016 SPRTN protease activity is controlled by three regulatory mechanisms: (1) a DNA switch triggering protease activity, (2) a ubiquitin switch controlling SPRTN chromatin accessibility, and (3) regulatory autocatalytic self-cleavage. Cellular, biochemical, and structural studies defined these mechanisms. Biochemical protease assays, structural studies, active-site mutagenesis, ubiquitin-binding domain mutagenesis, Xenopus egg extracts, cellular chromatin fractionation Molecular cell High 27871365
2016 SPRTN's DNA-binding capacity (distinct from its PIP box) is required for proper targeting of Pol η to DNA damage sites after UV exposure, demonstrating a direct link between SPRTN DNA binding and translesion synthesis regulation. In vitro DNA binding assay with purified SPRTN, DNA-binding domain mutagenesis, immunofluorescence of Pol η foci in cells expressing binding-defective SPRTN DNA repair Medium 27838458
2016 Crystal structure of human PCNA in complex with the DVC1/SPRTN PIP box peptide reveals a unique YF-type PIP box interaction; substitution of Y331 with Phe severely reduces PCNA binding affinity. X-ray crystallography, in vitro binding affinity measurements with PIP box mutants Biochemical and biophysical research communications High 27084448
2017 Purified human Spartan exhibits DNA-dependent protease activity capable of degrading proteins bound to DNA. Spartan is required for direct DPC removal in vivo and facilitates repair of formaldehyde-induced DPCs; its DPC repair function maps by epistasis to the RAD6-RAD18 DNA damage tolerance pathway. In vitro protease assay with purified Spartan, BrdU comet assay, DNA fiber assay, genetic epistasis with RAD6-RAD18 pathway components Nucleic acids research High 28053116
2017 Spartan deficiency in hypomorphic mice causes accumulation of Topoisomerase 1 covalently linked to DNA (TOP1-DPCs) specifically in liver, accompanied by DNA damage, aneuploidy, and spontaneous liver tumorigenesis, establishing a causal link between DPC repair deficiency and tumor suppression. RADAR assay for DPC isolation, immunoprecipitation to identify TOP1-DPCs, histopathology, flow cytometry in hypomorphic mouse livers Nucleic acids research High 28199696
2018 In Xenopus egg extracts, SPRTN and the proteasome act as two independent DPC proteases. Proteasome recruitment requires DPC polyubiquitylation (partially dependent on the ubiquitin ligase TRAIP), whereas SPRTN-mediated DPC degradation does not require polyubiquitylation but instead depends on nascent strand extension to within a few nucleotides of the DPC, indicating polymerase stalling activates SPRTN on both leading and lagging strand templates. Xenopus egg extract replication system, plasmid-based DPC substrates, proteasome inhibitors, SPRTN immunodepletion, nascent strand analysis Molecular cell High 30595436
2019 Crystal structure of the human SPRTN SprT domain bound to single-stranded DNA reveals a Zn2+-binding sub-domain (ZBD) that shields the active site metalloprotease sub-domain (MPD). The ZBD contains an ssDNA-binding site with a DNA-base-binding pocket formed by aromatic residues; mutations of ssDNA-binding residues diminish protease activity. X-ray crystallography, site-directed mutagenesis of ssDNA-binding residues, in vitro protease activity assays Cell reports High 30893605
2019 SPRTN proteolytically cleaves the C-terminal/inhibitory part of CHK1 during physiological DNA replication, liberating N-terminal CHK1 kinase active fragments that activate the ATR-CHK1 signaling cascade. In turn, CHK1 phosphorylates SPRTN at its C-terminal regulatory domain, stimulating SPRTN chromatin recruitment — forming a SPRTN-CHK1 cross-activation loop that promotes replication fork progression. In vitro protease assay with purified SPRTN and CHK1, mass spectrometry identification of cleavage fragments, phosphorylation assays, chromatin fractionation, siRNA knockdown, DNA fiber assay Nature communications High 31316063
2019 GCNA proteins (germline/pluripotent cell expressed) physically interact with Spartan/DVC-1 and topoisomerase II (TOP2) in both mice and C. elegans, and colocalize on condensed chromosomes during mitosis. GCNA mutants are hypersensitive to TOP2 poison, implicating a functional GCNA-Spartan-TOP2 axis in genome maintenance. Co-immunoprecipitation, immunofluorescence colocalization, genetic hypersensitivity assays in C. elegans and mouse spermatocytes Developmental cell Medium 31839538
2020 SPRTN displays strict DNA structure-specific protease activity: it cleaves DPCs at or in direct proximity to disruptions within double-stranded DNA (e.g., ssDNA-dsDNA junctions), whereas proteins crosslinked to intact dsDNA or ssDNA are not cleaved. NMR spectroscopy reveals a flexible bipartite DNA-binding strategy with two interfaces recognizing distinct structural features. In vitro protease assays with defined DPC model substrates, NMR spectroscopy, mutagenesis of DNA-binding interfaces Molecular cell High 32853547
2020 TEX264 forms a complex with p97 ATPase and SPRTN metalloprotease; TEX264 recognizes both unmodified and SUMO1-modified TOP1 and initiates TOP1cc repair by recruiting p97 and SPRTN. TEX264 localizes to the nuclear periphery and associates with DNA replication forks. Co-immunoprecipitation, proximity ligation assay, siRNA knockdown, immunofluorescence, DNA fiber assay, alkaline comet assay Nature communications High 32152270
2020 ATM/ATR phosphorylates and activates the deubiquitinase VCPIP1/VCIP135 in response to DPC induction; VCPIP1 then deubiquitinates SPRTN, promoting its chromatin relocalization. This deubiquitination is required for subsequent acetylation of SPRTN, which promotes SPRTN relocation to sites of chromatin damage. Co-immunoprecipitation, in vitro deubiquitination assay, chromatin fractionation, phospho-specific immunoblot, acetylation assays, VCPIP1 knockout mouse characterization Molecular cell High 32649882
2021 Monoubiquitylation of SPRTN is induced in an E3 ligase-independent manner and triggers autocatalytic self-cleavage in trans (inactivating SPRTN) while also priming it for proteasomal degradation in cis. The deubiquitylase USP7 antagonizes this negative regulation of SPRTN specifically in the presence of DPCs. In vitro ubiquitylation and protease assays, site-directed mutagenesis, cellular chromatin fractionation, co-immunoprecipitation with USP7 Nucleic acids research High 33348378
2021 DPC ubiquitylation recruits SPRTN to repair sites promoting DPC removal, while DPC SUMOylation prevents DNA double-strand break formation and HR activation by channeling repair toward SPRTN proteolysis. These two PTMs (ubiquitylation and SUMOylation) act as major signaling events in replication-coupled DPC repair. Chromatin fractionation, immunoprecipitation, siRNA knockdown, γH2AX foci assay, DPC isolation assay, HR reporter assay Cell reports Medium 34879279
2021 USP11 deubiquitinase interacts with SPRTN, cleaves monoubiquitinated SPRTN in cells and in vitro, and its depletion impairs SPRTN deubiquitination, promotes SPRTN auto-proteolysis, and causes accumulation of unrepaired DPCs. Co-immunoprecipitation, in vitro deubiquitination assay, DPC isolation assay, siRNA knockdown, immunoblot of SPRTN cleavage fragments The Journal of biological chemistry Medium 33567341
2021 SPRTN is the essential protease responsible for generating a C-terminally truncated form of MRE11 (TR-MRE11). The SPRTN-dependent cleavage site was mapped by tandem mass spectrometry and site-directed mutagenesis between MRE11 residues 559–580. TR-MRE11 has dramatically reduced nuclease activities due to deficient DNA binding, abolishes MRE11 recruitment to DSB sites, decreases HR repair efficiency, and increases cellular radiosensitivity. Tandem mass spectrometry, site-directed mutagenesis, in vitro nuclease assays, co-immunoprecipitation, immunofluorescence at DSB sites, HR reporter assay, clonogenic survival assay Cell death & disease High 33558481
2021 SPRTN interacts with PARP1 and forms nuclear foci colocalizing with the replicative marker CDC45 in response to PARP trapping. SPRTN-deficient cells are hypersensitive to talazoparib and olaparib (strong PARP trappers) but not veliparib, show delayed clearance of trapped PARP1, and increased replication fork stalling; SPRTN is deubiquitinated and epistatic with TLS in response to talazoparib. Co-immunoprecipitation, immunofluorescence, SPRTN knockout cells, DPC isolation assay, DNA fiber assay, epistasis analysis with TLS pathway Nucleic acids research Medium 34551432
2022 p97 (VCP/Cdc48), in cooperation with its ubiquitin adapters Ufd1-Npl4, unfolds polyubiquitinated DPC substrates to prepare them for proteolysis by SPRTN. Biochemically reconstituted: SPRTN alone cannot degrade tightly-folded Eos-DPC, but p97+Ufd1-Npl4 unfolds polyubiquitinated Eos-DPC enabling subsequent SPRTN proteolysis in a DNA-crosslink-dependent manner. Biochemical reconstitution with purified p97, Ufd1-Npl4, SPRTN, and fluorescent reporter Eos-DPC substrate; in vitro unfolding and protease assays The Journal of biological chemistry High 35469923
2023 SPRTN has an unexpected role in global-genome DPC repair that does not rely on replication-coupled detection. Replication-independent DPC cleavage by SPRTN requires SUMO-targeted ubiquitylation of the protein adduct, and defective ubiquitin binding of SPRTN patient variants compromises global-genome DPC repair causing synthetic lethality when combined with reduced proteasomal DPC repair. PxP (Purification of x-linked Proteins) technique, engineered patient variant cell lines, SUMO/ubiquitin pathway inhibitors, genetic complementation Nature communications High 36681662
2023 SPRTN-dependent proteolytic resection of DPCs (producing crosslinked peptides on DNA) is required upstream for activation of downstream DNA repair signaling via γH2AX phosphorylation and accumulation of DNA repair factors on chromatin. DPC repair is thus a two-step process: proteolytic resection by SPRTN followed by repair of the underlying DNA damage. STAR assay (novel DPC purification and quantification), immunoblot for γH2AX, chromatin fractionation, SPRTN knockdown/knockout Nucleic acids research Medium 36718861
2023 TDP1 and SPRTN repair histone H3-DPCs through sequential action: SPRTN-dependent upstream proteolysis is required for subsequent TDP1-mediated removal of crosslinked peptides. SPRTN and TDP1 function in different pathways for repair of endogenous TOP1-DPCs and total DPCs. SPRTN and TDP1 mutant zebrafish embryos, human RPE1 cells with SPRTN/TDP1 depletion, DPC quantification assays, camptothecin and formaldehyde treatment Open biology Medium 37788708
2025 Ubiquitin allosterically activates SPRTN by binding to SPRTN's protease domain (a site distinct from known ubiquitin-binding domains), promoting an open, active conformation as revealed by protein structure prediction, MD simulations, and NMR spectroscopy. Replacing key interfacial residues prevents allosteric activation, causing genomic instability and cell cycle defects. In vitro DPC reconstitution with SUMO/ubiquitin modifications, NMR spectroscopy, MD simulations, AlphaFold structure prediction, site-directed mutagenesis, cellular genomic instability and cell cycle assays Nature communications High 40691134
2025 The N-terminal SprT catalytic region of SPRTN possesses a ubiquitin-binding domain (USD — Ubiquitin Interface of SprT Domain) that binds ubiquitin chains in an avidity manner. USD-mediated binding to polyubiquitin chains leads to ~67-fold higher activation of SPRTN proteolysis toward polyubiquitinated DPCs compared to unmodified DPCs, while PCNA and monoUb-PCNA are poorly degraded. This establishes DPC polyubiquitylation as the key specificity signal for SPRTN. Biochemical pulldown assays, NMR spectroscopy, biophysical binding assays, in vitro protease activity assays with polyubiquitinated vs. unmodified DPC substrates, mutagenesis of USD Nucleic acids research High 40685547
2026 PARP1/2 sense DPCs and modify them with poly(ADP-ribose) (PAR) to promote SPRTN-dependent repair. SPRTN contains a Nudix homology domain (NHD) that mediates direct non-covalent PAR binding; mutation of NHD leads to sustained DPCs. Single-molecule analysis showed PARP1 + NAD+ significantly increases SPRTN binding to DPCs, establishing PARP1 as a direct recruiter of SPRTN to DPC sites. Single-molecule analysis, in vitro PAR-binding assay with purified SPRTN NHD, DPC quantification in NHD mutant cells, PARP1/2 inhibition assays bioRxiv : the preprint server for biologypreprint Medium 41542513
2026 DNA-induced conformational changes relieve SPRTN autoinhibition: ZBD maintains MPD in an autoinhibited state; BR together with DNA is essential to relieve ZBD-mediated inhibition of MPD, inducing an open conformation of the SPRTN N-terminus in cis. The autocleaved N-terminal SPRTN fragment (containing MPD+ZBD+BR) is enzymatically active and retains ubiquitin-dependent activation, overturning the dogma that autocatalytic cleavage inactivates the enzyme. Fluorescence FRET-based real-time protease assay, site-trapping approach, domain deletion mutagenesis, in vitro protease assays with purified truncated SPRTN variants bioRxiv : the preprint server for biologypreprint Medium 42094449

Source papers

Stage 0 corpus · 66 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2016 Metalloprotease SPRTN/DVC1 Orchestrates Replication-Coupled DNA-Protein Crosslink Repair. Molecular cell 206 27871366
2016 Mechanism and Regulation of DNA-Protein Crosslink Repair by the DNA-Dependent Metalloprotease SPRTN. Molecular cell 199 27871365
2014 Mutations in SPRTN cause early onset hepatocellular carcinoma, genomic instability and progeroid features. Nature genetics 176 25261934
2018 Replication-Coupled DNA-Protein Crosslink Repair by SPRTN and the Proteasome in Xenopus Egg Extracts. Molecular cell 154 30595436
2012 DVC1 (C1orf124) is a DNA damage-targeting p97 adaptor that promotes ubiquitin-dependent responses to replication blocks. Nature structural & molecular biology 154 23042605
2016 SPRTN is a mammalian DNA-binding metalloprotease that resolves DNA-protein crosslinks. eLife 142 27852435
2012 DVC1 (C1orf124) recruits the p97 protein segregase to sites of DNA damage. Nature structural & molecular biology 122 23042607
2012 Spartan/C1orf124, a reader of PCNA ubiquitylation and a regulator of UV-induced DNA damage response. Molecular cell 117 22681887
2017 Spartan deficiency causes accumulation of Topoisomerase 1 cleavage complexes and tumorigenesis. Nucleic acids research 97 28199696
2014 Spartan deficiency causes genomic instability and progeroid phenotypes. Nature communications 96 25501849
2020 TEX264 coordinates p97- and SPRTN-mediated resolution of topoisomerase 1-DNA adducts. Nature communications 89 32152270
2012 Proliferating cell nuclear antigen (PCNA)-binding protein C1orf124 is a regulator of translesion synthesis. The Journal of biological chemistry 86 22902628
2017 DNA-dependent protease activity of human Spartan facilitates replication of DNA-protein crosslink-containing DNA. Nucleic acids research 80 28053116
2012 Characterization of human Spartan/C1orf124, an ubiquitin-PCNA interacting regulator of DNA damage tolerance. Nucleic acids research 80 22987070
2012 A nucleoside- and ritonavir-sparing regimen containing atazanavir plus raltegravir in antiretroviral treatment-naïve HIV-infected patients: SPARTAN study results. HIV clinical trials 76 22592092
2012 Spartan/C1orf124 is important to prevent UV-induced mutagenesis. Cell cycle (Georgetown, Tex.) 63 22894931
2012 Regulation of error-prone translesion synthesis by Spartan/C1orf124. Nucleic acids research 54 23254330
2019 Safety findings from Phase 3 lasmiditan studies for acute treatment of migraine: Results from SAMURAI and SPARTAN. Cephalalgia : an international journal of headache 52 31166697
2020 Tandem Deubiquitination and Acetylation of SPRTN Promotes DNA-Protein Crosslink Repair and Protects against Aging. Molecular cell 49 32649882
2019 GCNA Interacts with Spartan and Topoisomerase II to Regulate Genome Stability. Developmental cell 49 31839538
2021 The protease SPRTN and SUMOylation coordinate DNA-protein crosslink repair to prevent genome instability. Cell reports 48 34879279
2020 DNA Structure-Specific Cleavage of DNA-Protein Crosslinks by the SPRTN Protease. Molecular cell 46 32853547
2019 Structural Insight into DNA-Dependent Activation of Human Metalloprotease Spartan. Cell reports 45 30893605
2005 Structures of NADH and CH3-H4folate complexes of Escherichia coli methylenetetrahydrofolate reductase reveal a spartan strategy for a ping-pong reaction. Biochemistry 42 16114881
2019 SPRTN protease and checkpoint kinase 1 cross-activation loop safeguards DNA replication. Nature communications 41 31316063
2013 DVC1-0101 to treat peripheral arterial disease: a Phase I/IIa open-label dose-escalation clinical trial. Molecular therapy : the journal of the American Society of Gene Therapy 40 23319060
2014 The Spartan ortholog maternal haploid is required for paternal chromosome integrity in the Drosophila zygote. Current biology : CB 35 25242033
2023 SPRTN patient variants cause global-genome DNA-protein crosslink repair defects. Nature communications 30 36681662
2021 A ubiquitin switch controls autocatalytic inactivation of the DNA-protein crosslink repair protease SPRTN. Nucleic acids research 30 33348378
2022 Mechanisms and Regulation of DNA-Protein Crosslink Repair During DNA Replication by SPRTN Protease. Frontiers in molecular biosciences 26 35782873
2021 Replication-dependent cytotoxicity and Spartan-mediated repair of trapped PARP1-DNA complexes. Nucleic acids research 24 34551432
2021 USP11 mediates repair of DNA-protein cross-links by deubiquitinating SPRTN metalloprotease. The Journal of biological chemistry 22 33567341
2022 Cross-species incompatibility between a DNA satellite and the Drosophila Spartan homolog poisons germline genome integrity. Current biology : CB 21 35643081
2020 Function and evolution of the DNA-protein crosslink proteases Wss1 and SPRTN. DNA repair 21 32058279
2022 Ubiquitin-directed AAA+ ATPase p97/VCP unfolds stable proteins crosslinked to DNA for proteolysis by SPRTN. The Journal of biological chemistry 20 35469923
2002 Comparative chronic toxicity and carcinogenicity of acrylonitrile by drinking water and oral intubation to Spartan Sprague-Dawley rats. Toxicology letters 18 12044704
2016 Crystal structure of human PCNA in complex with the PIP box of DVC1. Biochemical and biophysical research communications 16 27084448
2018 SPARTAN promotes genetic diversification of the immunoglobulin-variable gene locus in avian DT40 cells. DNA repair 15 29935364
2023 Tyrosyl-DNA phosphodiesterase 1 (TDP1) and SPRTN protease repair histone 3 and topoisomerase 1 DNA-protein crosslinks in vivo. Open biology 13 37788708
2016 The DNA-binding box of human SPARTAN contributes to the targeting of Polη to DNA damage sites. DNA repair 13 27838458
2022 Concomitant use of oral anticoagulants in patients with advanced prostate cancer receiving apalutamide: A post-hoc analysis of TITAN and SPARTAN studies. American journal of cancer research 12 35141028
2019 Validation of the Spartan RXCYP2C19 Genotyping Assay Utilizing Blood Samples. Clinical and translational science 12 31664775
2021 SPRTN protease-cleaved MRE11 decreases DNA repair and radiosensitises cancer cells. Cell death & disease 11 33558481
2020 The Trinity of SPRTN Protease Regulation. Trends in biochemical sciences 10 33183910
2023 SPRTN-dependent DPC degradation precedes repair of damaged DNA: a proof of concept revealed by the STAR assay. Nucleic acids research 9 36718861
2024 Sequence of Events in the Pathogenesis of Axial Spondyloarthritis: A Current Review-2023 SPARTAN Meeting Proceedings. Current rheumatology reports 8 38324125
2021 SPaRTAN, a computational framework for linking cell-surface receptors to transcriptional regulators. Nucleic acids research 8 34500467
2024 Effect of concomitant medications on treatment response and survival in non-metastatic castrate resistant prostate cancer: Exploratory analysis of the SPARTAN trial. European journal of cancer (Oxford, England : 1990) 6 39243730
2019 A model of DNA damage response activation at stalled replication forks by SPRTN. Nature communications 6 31831745
2016 Improved quality of life in patients with no-option critical limb ischemia undergoing gene therapy with DVC1-0101. Scientific reports 6 27418463
2024 Year in Review: Novel Insights in the Pathogenesis of Spondyloarthritis - SPARTAN 2024 Annual Meeting Proceedings. Current rheumatology reports 5 39731620
2024 Prior Local Therapy and First-Line Apalutamide in Patients With Nonmetastatic Castration-Resistant Prostate Cancer: A Secondary Analysis of the SPARTAN Randomized Clinical Trial. JAMA network open 3 39405060
2024 SPRTN metalloprotease participates in repair of ROS-mediated DNA-protein crosslinks. Scientific reports 3 39730693
2022 SPRTN and TDP1/TDP2 Independently Suppress 5-Aza-2'-deoxycytidine-Induced Genomic Instability in Human TK6 Cell Line. Chemical research in toxicology 3 36282523
2025 Spondyloarthritis Research and Treatment Network (SPARTAN) Clinical and Imaging Year in Review 2024. Current rheumatology reports 2 40591037
2025 The dual ubiquitin binding mode of SPRTN secures rapid spatiotemporal proteolysis of DNA-protein crosslinks. Nucleic acids research 2 40685547
2025 Allosteric activation of the SPRTN protease by ubiquitin maintains genome stability. Nature communications 2 40691134
2024 NMR Metabolite Profiling and Antioxidant Properties of Spartan, Jewels, Misty, and Camelia Blueberries. Journal of agricultural and food chemistry 2 39348468
2023 SPRTN is involved in hepatocellular carcinoma development through the ER stress response. Cancer gene therapy 2 38086993
2016 Extending and Applying Spartan to Perform Temporal Sensitivity Analyses for Predicting Changes in Influential Biological Pathways in Computational Models. IEEE/ACM transactions on computational biology and bioinformatics 2 26887007
2026 Statin use and outcomes in advanced prostate cancer:Secondary analysis of the SPARTAN trial. Urologic oncology 1 41654482
2024 The dual ubiquitin binding mode of SPRTN secures rapid spatiotemporal proteolysis of DNA-protein crosslinks. bioRxiv : the preprint server for biology 1 39651247
2026 PARP1 recruits SPRTN to DNA-protein crosslinks through a conserved poly-ADP-ribose binding domain. bioRxiv : the preprint server for biology 0 41542513
2026 SPARTAN: automated table detection and extraction from documents using advanced OpenCV heuristics and OCR techniques. Scientific reports 0 41882048
2026 DNA-induced conformational changes in SPRTN relieve its auto-inhibitory effect on protease activity. bioRxiv : the preprint server for biology 0 42094449
2021 [Apalutamide in patients with high-risk M0CRPC: data from the pivotal SPARTAN study and initial experience from a compassionate use program]. Aktuelle Urologie 0 33621992

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