Affinage

TDRD1

Tudor domain-containing protein 1 · UniProt Q9BXT4

Length
1180 aa
Mass
132.0 kDa
Annotated
2026-04-28
20 papers in source corpus 9 papers cited in narrative 9 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

TDRD1 is a germline-enriched scaffold protein whose extended Tudor domains recognize symmetrically dimethylated arginine (sDMA) motifs on Piwi-family proteins to nucleate piRNA pathway complexes essential for transposon silencing and spermatogenesis. Its four tandem Tudor domains bind sDMA-modified MILI peptides with differential affinity—TD2 and TD3 being the principal readers—while its coiled-coil domain drives liquid-liquid phase separation to assemble intermitochondrial cement (IMC), the perinuclear granule compartment required for piRNA biogenesis; phase separation–deficient TDRD1 in mice abolishes IMC, derepresses transposons, and causes spermatogenic arrest (PMID:22996915, PMID:39029469). TDRD1 localization to nuage depends on MVH/DDX4 and on recruitment to mitochondria by MILI, and its complexes contain piRNAs and target transcripts that represent piRNA biogenesis intermediates (PMID:17038506, PMID:21743441). In prostate cancer, TDRD1 is ectopically activated by the ERG transcription factor and functions in snRNP biogenesis by bridging PRMT5-methylated Sm proteins and the Cajal body scaffold Coilin, with TDRD1 loss disrupting Cajal body integrity and reducing proliferation (PMID:23319146, PMID:37041411).

Mechanistic history

Synthesis pass · year-by-year structured walk · 7 steps
  1. 2006 High

    Establishing TDRD1 as a nuage/IMC component whose localization depends on MVH/DDX4 resolved where in the germ cell TDRD1 operates and placed it in a genetic hierarchy downstream of the RNA helicase Vasa.

    Evidence Gene knockout in mice with immunofluorescence and genetic epistasis with Mvh/Ddx4 mutants

    PMID:17038506 PMID:17141210

    Open questions at the time
    • Direct binding targets of TDRD1 were unknown
    • No structural information on Tudor domain recognition
    • Mechanism by which TDRD1 promotes IMC assembly was unresolved
  2. 2009 High

    Demonstration that TDRD1 physically interacts with both MILI and MIWI identified the Piwi proteins as direct partners and showed that complex integrity is required for chromatoid body formation, linking TDRD1 to the piRNA pathway.

    Evidence Reciprocal co-immunoprecipitation from mouse testis lysates; immunofluorescence in Miwi-null spermatids

    PMID:19735482

    Open questions at the time
    • Whether interaction depends on arginine methylation was untested
    • RNA content of TDRD1 complexes was unknown
  3. 2011 High

    Work in zebrafish showed that TDRD1 Tudor domains specifically recognize sDMA modifications on Piwi proteins and that TDRD1 complexes contain piRNAs and longer target transcripts (TATs), establishing TDRD1 as a scaffold coupling Piwi recognition to piRNA biogenesis intermediates.

    Evidence Co-IP with sDMA specificity analysis, RNA-seq of TDRD1 complexes, loss-of-function in zebrafish

    PMID:21743441

    Open questions at the time
    • Structural basis of sDMA recognition by individual Tudor domains was unknown
    • Relative contributions of the four Tudor domains were unresolved
  4. 2012 High

    Crystal structure of the TD3–sDMA-MILI peptide complex and systematic binding measurements across all four Tudor domains revealed that TD2 and TD3 are the principal sDMA readers, while TD1 has a degenerate aromatic cage, defining the molecular logic of multivalent Piwi recognition.

    Evidence X-ray crystallography, ITC/fluorescence binding, NMR titration, SAXS, active-site mutagenesis

    PMID:22996915

    Open questions at the time
    • How multivalent Tudor–Piwi interactions organize higher-order assemblies was unclear
    • Role of non-Tudor domains (coiled-coil, IDR) was uncharacterized
  5. 2013 Medium

    Identification of ERG-driven transcriptional activation and promoter demethylation as the mechanism of ectopic TDRD1 expression in prostate cancer connected a germline piRNA factor to oncogenesis.

    Evidence ERG shRNA/overexpression, promoter reporter and mutant analysis, MeDIP-Seq, bisulfite sequencing, DNMT inhibitor treatment

    PMID:23319146 PMID:23555854

    Open questions at the time
    • Functional consequences of TDRD1 expression in cancer cells were not yet defined
    • Whether TDRD1 uses sDMA-reading activity in somatic cells was unknown
  6. 2023 Medium

    Discovery that TDRD1 in prostate cancer cells bridges PRMT5-methylated Sm proteins and Cajal body scaffold Coilin to promote snRNP biogenesis revealed a non-piRNA function for TDRD1's sDMA-reading activity in somatic cancer cells.

    Evidence Mass spectrometry interactome, co-IP of methylated Sm and Coilin, TDRD1 ablation with Cajal body and proliferation assays

    PMID:37041411

    Open questions at the time
    • Whether this snRNP function occurs in normal germ cells is untested
    • The specific Tudor domain(s) engaging Sm proteins vs. Coilin are unidentified
    • Single-lab finding awaits independent replication
  7. 2024 High

    Reconstitution of TDRD1-driven phase separation showed that the coiled-coil domain (via tetramerization) cooperates with Tudor-domain multivalency to drive IMC assembly among mitochondria, with phase separation–deficient knock-in mice failing to assemble IMC and arresting spermatogenesis, establishing phase separation as the biophysical mechanism underlying nuage organization.

    Evidence In vitro phase separation assays, domain deletion/mutation, mouse knock-in models, piRNA sequencing, transposon expression analysis

    PMID:39029469

    Open questions at the time
    • How TDRD1 condensates are regulated (post-translational modifications, client stoichiometry) is unknown
    • Whether phase separation contributes to TDRD1's somatic cancer functions has not been tested
    • The invertebrate mechanisms that substitute for TDRD1-driven phase separation remain uncharacterized

Open questions

Synthesis pass · forward-looking unresolved questions
  • Key open questions include the full piRNA precursor processing steps occurring within TDRD1 condensates, how the four Tudor domains coordinate simultaneous engagement of multiple methylated clients in vivo, and whether TDRD1's phase separation and snRNP biogenesis functions intersect in cancer.
  • No reconstituted piRNA processing assay with TDRD1 condensates exists
  • Stoichiometry and dynamics of Tudor–Piwi engagement in condensates are unresolved
  • Relationship between phase separation capacity and oncogenic function is untested

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0060090 molecular adaptor activity 3 GO:0042393 histone binding 1
Localization
GO:0005739 mitochondrion 2 GO:0005634 nucleus 1 GO:0005829 cytosol 1
Pathway
R-HSA-8953854 Metabolism of RNA 3
Partners
COILMILIMIWIMVHPRMT5TDRD6TDRD7
Complex memberships
TDRD1-MILI-piRNA complexpiRNA pathway nuage/IMC granule

Evidence

Reading pass · 9 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2006 TDRD1/MTR-1 localizes to nuage/germinal granules (specifically intermitochondrial cement) in mouse male germ cells, and its intracellular localization is downstream of MVH/DDX4 (mouse vasa homologue). Loss of TDRD1 abolishes intermitochondrial cement formation but chromatoid bodies persist, while MVH mutants show strong reduction of intermitochondrial cement. Targeted gene knockout in mice, subcellular localization by immunofluorescence, genetic epistasis with Mvh/Ddx4 mutants Proceedings of the National Academy of Sciences of the United States of America High 17038506
2006 TDRD1/MTR-1, TDRD6, and TDRD7/TRAP co-localize to nuage and form a ribonucleoprotein complex together; their co-localization is disrupted in Mvh/Ddx4 mutants. A single Tudor domain is a structural unit sufficient for nuage localization, but truncated dominant-negative forms are detrimental to meiotic spermatocytes. Co-immunoprecipitation, in vivo overexpression of truncated forms, genetic epistasis with Mvh mutants, immunofluorescence localization Developmental biology High 17141210
2009 TDRD1/MTR-1 physically interacts with both MILI and MIWI (mouse Piwi family proteins) in adult mouse testes, forming a complex whose integrity is required for proper subcellular localization of MILI and TDRD1, and for chromatoid body formation in round spermatids. Co-immunoprecipitation from mouse testis lysates, immunofluorescence localization in Miwi-null spermatids Genes to cells : devoted to molecular & cellular mechanisms High 19735482
2011 Zebrafish Tdrd1 acts as a molecular scaffold binding both Piwi proteins (Ziwi and Zili) through specific tudor domain–symmetrically dimethylated arginine (sDMA) interactions, and its complexes contain piRNAs and longer transcripts (Tdrd1-associated transcripts, TATs) representing likely cleaved Piwi pathway targets and piRNA biogenesis intermediates. Tdrd1 is required for efficient Piwi-pathway activity and nuage formation. Co-immunoprecipitation, sequence specificity analysis of tudor domain–sDMA interactions, RNA sequencing of Tdrd1 complexes, loss-of-function in zebrafish The EMBO journal High 21743441
2012 The four extended Tudor domains (TDs) of murine TDRD1 bind symmetrically dimethylated arginine (sDMA)-containing peptides from MILI with differential affinity: TD2 and TD3 show preference for consecutive MILI peptides, TD4 has lower affinity, and TD1 has very weak affinity due to a non-consensus aromatic cage that can be restored by a single point mutation. Crystal structure of TD3 bound to a methylated MILI peptide reveals an unexpected peptide orientation with contacts outside the aromatic cage. Binding affinity measurements (ITC/fluorescence), pull-down with endogenous Piwi proteins, crystal structure of TD3–sDMA peptide complex, solution NMR titration, small-angle X-ray scattering (SAXS) of tandem Tudor domains, active-site mutagenesis RNA (New York, N.Y.) High 22996915
2013 ERG transcription factor directly activates TDRD1 transcription in prostate cancer by binding a functional ERG-binding site in the TDRD1 promoter; ERG shRNA knockdown reduces TDRD1 expression and decreases TDRD1 promoter activity. shRNA knockdown of ERG, promoter reporter assay, mutation analysis of ERG binding site in TDRD1 promoter International journal of cancer Medium 23319146
2013 ERG governs loss of DNA methylation at the TDRD1 promoter-associated CpG island, leading to TDRD1 overexpression; demethylation of the TDRD1 promoter by DNA methyltransferase inhibitors induces TDRD1 in ERG-negative prostate cancer cells. MeDIP-Seq, bisulfite sequencing, ERG siRNA knockdown and forced overexpression, treatment with DNA methyltransferase inhibitors PloS one Medium 23555854
2023 In prostate cancer cells, TDRD1 interacts with methylated Sm proteins (in a PRMT5-dependent manner) in the cytoplasm and with Coilin (scaffold of Cajal bodies) in the nucleus. TDRD1 ablation disrupts Cajal body integrity, impairs snRNP biogenesis, and reduces prostate cancer cell proliferation, defining a PRMT5-TDRD1 signaling axis. Mass spectrometry interactome, co-immunoprecipitation of methylated Sm proteins and Coilin, TDRD1 knockdown/ablation with Cajal body immunofluorescence and proliferation assays Oncogene Medium 37041411
2024 TDRD1 triggers intermitochondrial cement (IMC) assembly via phase separation, driven by cooperation of its tetramerized coiled-coil domain and dimethylarginine-binding Tudor domains (but independent of its intrinsically disordered region). TDRD1 is recruited to mitochondria by MILI, then enhances mitochondrial clustering and triggers IMC assembly to promote piRNA processing. Phase separation-deficient TDRD1 in mice disrupts IMC assembly, impairs piRNA biogenesis, causes transposon de-repression, and leads to spermatogenic arrest. This phase separation mechanism is conserved in vertebrates but not invertebrates. In vitro phase separation assays, domain deletion and mutation analysis, mouse knock-in models with phase separation-deficient TDRD1, piRNA sequencing, transposon expression analysis, immunofluorescence of mitochondria and IMC, co-immunoprecipitation with MILI Developmental cell High 39029469

Source papers

Stage 0 corpus · 20 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2006 Tdrd1/Mtr-1, a tudor-related gene, is essential for male germ-cell differentiation and nuage/germinal granule formation in mice. Proceedings of the National Academy of Sciences of the United States of America 204 17038506
2006 Tudor-related proteins TDRD1/MTR-1, TDRD6 and TDRD7/TRAP: domain composition, intracellular localization, and function in male germ cells in mice. Developmental biology 127 17141210
2011 Tdrd1 acts as a molecular scaffold for Piwi proteins and piRNA targets in zebrafish. The EMBO journal 67 21743441
2009 Associations between PIWI proteins and TDRD1/MTR-1 are critical for integrated subcellular localization in murine male germ cells. Genes to cells : devoted to molecular & cellular mechanisms 57 19735482
2013 Identification of TDRD1 as a direct target gene of ERG in primary prostate cancer. International journal of cancer 56 23319146
2012 The multiple Tudor domain-containing protein TDRD1 is a molecular scaffold for mouse Piwi proteins and piRNA biogenesis factors. RNA (New York, N.Y.) 47 22996915
2014 Methylation of PITX2, HOXD3, RASSF1 and TDRD1 predicts biochemical recurrence in high-risk prostate cancer. Journal of cancer research and clinical oncology 25 24938434
2013 ERG induces epigenetic activation of Tudor domain-containing protein 1 (TDRD1) in ERG rearrangement-positive prostate cancer. PloS one 24 23555854
2020 Testicular expression of TDRD1, TDRD5, TDRD9 and TDRD12 in azoospermia. BMC medical genetics 23 32059713
2015 Gonad specific genes in Atlantic salmon (Salmon salar L.): characterization of tdrd7-2, dazl-2, piwil1 and tdrd1 genes. Gene 17 25668702
2016 The Germ Cell Gene TDRD1 as an ERG Target Gene and a Novel Prostate Cancer Biomarker. The Prostate 16 27272765
2024 TDRD1 phase separation drives intermitochondrial cement assembly to promote piRNA biogenesis and fertility. Developmental cell 15 39029469
2018 tdrd1 is a germline-specific and sexually dimorphically expressed gene in Paralichthys olivaceus. Gene 14 29920365
2016 Association of a TDRD1 variant with spermatogenic failure susceptibility in the Han Chinese. Journal of assisted reproduction and genetics 11 27233649
2023 The cancer testis antigen TDRD1 regulates prostate cancer proliferation by associating with the snRNP biogenesis machinery. Oncogene 7 37041411
2022 DNA hypomethylation activation Wnt/TCF7L2/TDRD1 pathway promotes spermatogonial stem cell formation. Journal of cellular physiology 4 35790000
2020 Upregulation of TDRD1 Promotes the Sexual Maturation in Allotetraploids Hybridized from Red Crucian Carp (Carassius auratus Red var) (♀) and Common Carp (Cyprinus carpio L) (♂). Journal of proteome research 3 32286072
2023 H3K4me2 cooperates with Wnt/TCF7L2 to regulate TDRD1 and promote chicken spermatogonia stem cell formation. Poultry science 2 36921513
2022 Characteristics of the TDRD1 gene promoter in chickens. Molecular genetics and genomics : MGG 2 35347417
2023 The cancer testis antigen TDRD1 regulates prostate cancer proliferation by associating with snRNP biogenesis machinery. Research square 0 36865141