Affinage

TTF2

Transcription termination factor 2 · UniProt Q9UNY4

Length
1162 aa
Mass
129.6 kDa
Annotated
2026-06-10
20 papers in source corpus 14 papers cited in narrative 14 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 6/6 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

The TTF2 timeline describes two distinct proteins under colliding symbols, and the on-target gene for this entry is the human SNF2-family ATPase TTF2 (HuF2/hLodestar), a cell-cycle-regulated machine that clears chromatin-bound machinery during mitosis (PMID:15467445, PMID:39651145). TTF2 functions as an RNA polymerase II termination factor that uses its ATPase activity to evict RNA Pol II from condensed mitotic chromosomes; this role is genetically defined, as knockdown causes RNA Pol II retention that is rescued by an siRNA-resistant TTF2 (PMID:15467445). In an ATPase-independent capacity, TTF2 acts as a molecular bridge that drives replisome disassembly at stalled mitotic replication forks: an N-terminal zinc finger recognizes Cyclin B-CDK1-phosphorylated TRAIP while an adjacent NPF motif binds the non-catalytic POLE2 subunit of DNA polymerase epsilon, tethering the TRAIP E3 ubiquitin ligase to the CMG helicase to direct CMG ubiquitylation, fork cleavage, and mitotic DNA synthesis [PMID:39651145, PMID:bio_10.1101_2024.12.01.626218, PMID:bio_10.1101_2025.03.17.643635]. TTF2 protein oscillates across the cell cycle and is destroyed by APC/C-CDH1, and it also sequesters CDC20 to restrain mitotic checkpoint complex assembly until its degradation releases CDC20 (PMID:40410652). Separately, TTF2 associates with the spliceosome through the splicing factor CDC5L (PMID:12927788). The thyroid transcription-factor findings in this corpus ((PMID:9214635)–(PMID:12165566), (PMID:16882747), (PMID:9446794)) describe FOXE1/TTF-2, a different forkhead protein sharing the 'TTF-2' name, and are not part of this gene's mechanism.

Mechanistic history

Synthesis pass · year-by-year structured walk · 5 steps
  1. 2003 Medium

    Established the first molecular partner of the SNF2-family ATPase HuF2/TTF2, linking it to pre-mRNA splicing and indicating a nuclear RNA-processing function.

    Evidence Yeast two-hybrid and Co-IP from HeLa nuclear extract identifying CDC5L interaction, plus a dominant-negative splicing-inhibition assay

    PMID:12927788

    Open questions at the time
    • Does not define whether ATPase activity is required for splicing-complex association
    • Functional role of the CDC5L interaction in normal splicing not resolved beyond a truncation-based inhibition
  2. 2004 High

    Defined TTF2 as the factor responsible for mitotic transcriptional repression by showing it is required to remove RNA Pol II from condensed chromosomes.

    Evidence siRNA knockdown with siRNA-resistant GFP-TTF2 rescue and immunofluorescence of mitotic chromosomes

    PMID:15467445

    Open questions at the time
    • Did not biochemically separate ATPase-dependent from ATPase-independent activities
    • Mechanism of Pol II eviction at molecular resolution not established
  3. 2024 High

    Resolved an ATPase-independent function: TTF2 bridges TRAIP to the replisome to trigger CMG unloading at stalled mitotic forks, separating this activity from its ATPase-dependent Pol II eviction.

    Evidence Xenopus egg extract replisome disassembly reconstitution, domain mutagenesis, phosphorylation analysis, and Co-IP, independently corroborated by a concurrent preprint

    PMID:39651145 PMID:bio_10.1101_2024.12.01.626218

    Open questions at the time
    • Both reports are preprints
    • Structural basis of simultaneous TRAIP and Polε engagement not solved
    • In vivo consequences of disrupting only the bridge in human cells not detailed
  4. 2025 Medium

    Mapped the POLE2-binding determinant to a specific NPF motif, providing the molecular contact point by which TTF2 docks onto DNA polymerase epsilon.

    Evidence Native holdup quantitative affinity assay with NPF-motif mutagenesis and AlphaFold prediction

    PMID:bio_10.1101_2025.03.17.643635

    Open questions at the time
    • Single-lab preprint
    • Micromolar affinity functional relevance in the intact replisome not validated
  5. 2025 Medium

    Connected TTF2 abundance to cell-cycle control, showing APC/C-CDH1-driven degradation and CDC20 sequestration that modulates mitotic checkpoint complex assembly.

    Evidence Cell-cycle synchronization, Co-IP, ubiquitination and proteasome-inhibitor assays, and genetic perturbation with cell-cycle readouts

    PMID:40410652

    Open questions at the time
    • Single lab, not independently replicated
    • Whether CDC20 sequestration is direct and how it integrates with the TRAIP/replisome role is unresolved

Open questions

Synthesis pass · forward-looking unresolved questions
  • How TTF2's two biochemical modes — ATPase-dependent RNA Pol II eviction and ATPase-independent replisome disassembly — are coordinated within a single mitotic cell remains unresolved.
  • No structure of full-length TTF2 with its partners
  • Mechanism switching between substrates (chromatin Pol II vs stalled replisomes) unknown
  • Several key mechanistic findings remain in preprint form

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0060090 molecular adaptor activity 3 GO:0140096 catalytic activity, acting on a protein 2 GO:0140657 ATP-dependent activity 2
Localization
GO:0005634 nucleus 1 GO:0005694 chromosome 1
Pathway
R-HSA-1640170 Cell Cycle 3 R-HSA-69306 DNA Replication 2 R-HSA-8953854 Metabolism of RNA 1
Partners
CDC20CDC5LPOLE2TRAIP

Evidence

Reading pass · 14 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
1997 TTF-2 (mouse) is a forkhead domain-containing DNA-binding protein that recognizes sites on both thyroglobulin (Tg) and thyroperoxidase (TPO) promoters; its expression is transiently downregulated in the developing thyroid just before onset of Tg and TPO gene expression, suggesting a role as a negative controller of thyroid-specific gene expression during development. cDNA cloning, DNA-binding assays, in situ hybridization/expression analysis in developing mouse thyroid The EMBO journal Medium 9214635
1997 TTF-2 mRNA levels are transcriptionally upregulated by TSH (via cAMP/forskolin), insulin, and IGF-I in FRTL-5 thyroid cells in a dose- and time-dependent manner requiring ongoing protein synthesis, positioning TTF-2 as a mediator of hormonal transcriptional activation of thyroid-specific genes. Northern blot, nuclear run-off transcription assay, pharmacological treatment of FRTL-5 cells The Journal of biological chemistry Medium 9287345
1998 A missense mutation (Ala65Val) within the forkhead domain of human TTF-2 (FKHL15/FOXE1) causes impaired DNA binding and loss of transcriptional function, establishing that DNA-binding activity of the forkhead domain is required for TTF-2's role in thyroid and palate development. Homozygosity mapping, direct sequencing, DNA-binding assay, transcriptional reporter assay with mutant protein Nature genetics High 9697705
1999 TTF-2 physically interacts with CTF/NF-1 proteins (specifically CTF/NF1-C, which is itself hormonally regulated by TSH/cAMP/insulin) at the TPO promoter; this interaction is required for efficient hormonal regulation of TPO gene expression, and spacing between their binding sites is critical for promoter activity. GST pull-down assay, transfection/reporter assays, protein-DNA interaction (EMSA), spacing mutagenesis The Journal of biological chemistry High 10329730
2000 TTF-2 acts as a promoter-specific, DNA-binding-independent transcriptional repressor of TTF-1 and Pax-8 activity; the minimal repressor domain functions as an independent domain and repression occurs without TTF-2 binding DNA, suggesting it interferes with a specific cofactor required for TTF-1 and Pax-8 activity. Transcriptional reporter assays, domain deletion/mutagenesis analysis, co-transfection experiments Biochemical and biophysical research communications Medium 10944465
2002 A second missense mutation in the forkhead domain of TTF-2 (S57N) causes impaired DNA binding and partial loss of transcriptional function, confirming that the forkhead domain mediates DNA binding necessary for TTF-2 function in thyroid and palate development. Direct sequencing, DNA-binding assay, transcriptional reporter assay with mutant protein Human molecular genetics High 12165566
2003 HuF2 (TTF2/hLodestar), a SNF2-family ATPase, interacts with the pre-mRNA splicing factor CDC5L in yeast two-hybrid and HeLa nuclear extract, associates with human splicing complexes, and a truncated HuF2 polypeptide overlapping the CDC5L-binding region inhibits pre-mRNA splicing by disrupting spliceosome assembly. Yeast two-hybrid, co-immunoprecipitation from HeLa nuclear extract, in vitro splicing inhibition assay, spliceosome assembly assay Biochemical and biophysical research communications Medium 12927788
2004 TTF2 (human SNF2-family ATPase) is an RNA polymerase II termination factor responsible for mitotic repression of transcription elongation; siRNA-mediated knockdown of TTF2 causes retention of RNA polymerase II on condensed mitotic chromosomes, and this phenotype is rescued by expression of an siRNA-resistant GFP-TTF2 replacement vector, proving TTF2 is directly responsible. siRNA knockdown, rescue experiment with siRNA-resistant GFP-TTF2 replacement vector, immunofluorescence microscopy of mitotic chromosomes Cell cycle (Georgetown, Tex.) High 15467445
2006 A third missense mutation (R102C) within the forkhead DNA-binding domain of TTF-2 causes complete loss of DNA binding and transcriptional inactivity, further confirming the forkhead domain as the essential functional domain for DNA binding. Direct sequencing, DNA-binding assay, transcriptional reporter assay with mutant protein The Journal of clinical endocrinology and metabolism High 16882747
2024 TTF2 (SWI/SNF ATPase) promotes replisome disassembly at stalled replication forks in mitosis by tethering the TRAIP E3 ubiquitin ligase to the CMG helicase via: (1) an N-terminal Zinc finger domain binding phosphorylated TRAIP (phosphorylation by mitotic Cyclin B-CDK1), and (2) an adjacent TTF2 peptide contacting CMG-associated DNA polymerase ε (Polε/POLE2). This TRAIP-TTF2-Polε bridge is independent of TTF2 ATPase activity and is essential for CMG unloading and stalled fork cleavage. In contrast, RNAPII eviction from mitotic chromosomes requires TTF2 ATPase activity. Xenopus egg extract replisome disassembly assay, domain mutagenesis, phosphorylation analysis, co-immunoprecipitation, biochemical reconstitution bioRxivpreprint High 39651145
2024 TTF2 couples the TRAIP ubiquitin ligase to DNA Polymerase ε (Polε) via tandem Zinc fingers recognizing phosphorylated TRAIP and a motif binding POLE2, causing TRAIP to ubiquitylate CMG helicase to trigger replisome disassembly and Mitotic DNA Synthesis (MiDAS); TTF2 ATPase activity is separately required for RNA Pol II removal from mitotic chromosomes. Biochemical reconstitution, co-immunoprecipitation, domain mutagenesis, ubiquitylation assay, MiDAS assay bioRxivpreprint High bio_10.1101_2024.12.01.626218
2025 TTF2 protein levels oscillate during the cell cycle (high in S and G2/M, low in late mitosis and G1); TTF2 is ubiquitinated by APC/C-CDH1 and degraded via the proteasome; TTF2 binds CDC20 and prevents mitotic checkpoint complex (MCC) formation during normal mitosis; when TTF2 is degraded by APC/C-CDH1 upon persistent G2/M arrest, CDC20 is released to promote MCC assembly. Cell cycle synchronization/flow cytometry, co-immunoprecipitation, ubiquitination assay, siRNA knockdown/overexpression with cell cycle phenotype readout, proteasome inhibitor treatment Science China. Life sciences Medium 40410652
2025 TTF2 contains an NPF motif that binds to the non-catalytic POLE2 subunit of DNA polymerase ε with micromolar affinity; mutation of this NPF motif abolishes binding in cell extracts. Native holdup assay (quantitative peptide affinity), mutational analysis, proteome-scale affinity screen, AlphaFold structural prediction bioRxivpreprint Medium bio_10.1101_2025.03.17.643635
1998 TTF-2 DNA-binding activity is detectable in unstimulated dog thyrocytes and increases with forskolin treatment, but mutation of the TTF-2 binding site in the thyroglobulin promoter leaves cAMP-dependent activity largely intact, indicating TTF-2 does NOT play a dominant role in cAMP-dependent control of thyroglobulin gene transcription in primary dog thyrocytes (negative finding). Nuclear extract binding assay with radiolabeled probe, transient transfection reporter assay with site-directed mutagenesis of TTF-2 binding site Biochemical and biophysical research communications Medium 9446794

Source papers

Stage 0 corpus · 20 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
1998 Mutation of the gene encoding human TTF-2 associated with thyroid agenesis, cleft palate and choanal atresia. Nature genetics 301 9697705
1997 TTF-2, a new forkhead protein, shows a temporal expression in the developing thyroid which is consistent with a role in controlling the onset of differentiation. The EMBO journal 219 9214635
2007 Diagnostic utility of thyroid transcription factors Pax8 and TTF-2 (FoxE1) in thyroid epithelial neoplasms. Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc 204 18084247
2002 A novel loss-of-function mutation in TTF-2 is associated with congenital hypothyroidism, thyroid agenesis and cleft palate. Human molecular genetics 114 12165566
1997 Transcriptional control of the forkhead thyroid transcription factor TTF-2 by thyrotropin, insulin, and insulin-like growth factor I. The Journal of biological chemistry 64 9287345
2013 Contribution of ATM and FOXE1 (TTF2) to risk of papillary thyroid carcinoma in Belarusian children exposed to radiation. International journal of cancer 52 24105688
2000 The thyroid transcription factor 2 (TTF-2) is a promoter-specific DNA-binding independent transcriptional repressor. Biochemical and biophysical research communications 50 10944465
2006 A novel missense mutation in human TTF-2 (FKHL15) gene associated with congenital hypothyroidism but not athyreosis. The Journal of clinical endocrinology and metabolism 45 16882747
1999 The interaction between the forkhead thyroid transcription factor TTF-2 and the constitutive factor CTF/NF-1 is required for efficient hormonal regulation of the thyroperoxidase gene transcription. The Journal of biological chemistry 42 10329730
2010 Spectrum of Human Foxe1/TTF2 Mutations. Hormone research in paediatrics 41 20453517
2004 Genetic analysis of TTF-2 gene in children with congenital hypothyroidism and cleft palate, congenital hypothyroidism, or isolated cleft palate. Thyroid : official journal of the American Thyroid Association 19 15320969
2004 Rescue of the TTF2 knockdown phenotype with an siRNA-resistant replacement vector. Cell cycle (Georgetown, Tex.) 15 15467445
2003 hLodestar/HuF2 interacts with CDC5L and is involved in pre-mRNA splicing. Biochemical and biophysical research communications 14 12927788
2012 Overexpression of mouse TTF-2 gene causes cleft palate. Journal of cellular and molecular medicine 11 22304410
2015 Replication and Meta-Analysis of Common Gene Mutations in TTF1 and TTF2 with Papillary Thyroid Cancer. Medicine 10 26356687
2004 TTF-2 stimulates expression of 17 genes, including one novel thyroid-specific gene which might be involved in thyroid development. Molecular and cellular endocrinology 10 15223130
1998 TTF-2 does not appear to be a key mediator of the effect of cyclic AMP on thyroglobulin gene transcription in primary cultured dog thyrocytes. Biochemical and biophysical research communications 8 9446794
2024 TTF2 promotes replisome eviction from stalled forks in mitosis. bioRxiv : the preprint server for biology 6 39651145
2025 Mutual regulation between cell cycle and transcription termination factor TTF2. Science China. Life sciences 2 40410652
2012 Molecular Analysis of TTF-1 and TTF-2 Genes in Patients with Early Onset Papillary Thyroid Carcinoma. Journal of oncology 0 22481925

Missed literature

Know a paper Affinage missed for TTF2? Flag it for the maintainers and the community.

No submissions yet.