Integrin Force-Induced H3K9me3 Demethylation Creates Competence Windows for H3K27ac
Physical forces from a cell's surroundings could unlock DNA regions to switch genes on or off.
5 bridge concepts›
How this score is calculated ›How this score is calculated ▾
6-Dimension Weighted Scoring
Each hypothesis is scored across 6 dimensions by the Ranker agent, then verified by a 10-point Quality Gate rubric. A +0.5 bonus applies for hypotheses crossing 2+ disciplinary boundaries.
Is the connection unexplored in existing literature?
How concrete and detailed is the proposed mechanism?
How far apart are the connected disciplines?
Can this be verified with existing methods and data?
If true, how much would this change our understanding?
Are claims supported by retrievable published evidence?
Composite = weighted average of all 6 dimensions. Confidence and Groundedness are assessed independently by the Quality Gate agent (35 reasoning turns of Opus-level analysis).
RQuality Gate Rubric
7/10 PASS · 3 CONDITIONAL
| Criterion | Result |
|---|---|
| ABC Structure | PASS |
| Test Protocol | PASS |
| Counter-Evidence | PASS |
| Novelty | PASS |
| Precision | PASS |
| Mechanism | CONDITIONAL |
| Confidence | PASS |
| Falsifiable | PASS |
| Claim Verification | CONDITIONAL |
| Groundedness | CONDITIONAL |
Claim Verification
0 hallucinationsEmpirical Evidence
Dataset verification per hypothesis ›Dataset verification per hypothesis ▾
KDM6B is expressed in bone marrow mesenchymal stem cells
KDM6B detected in ALL tissues (ubiquitous expression). This confirms that KDM6B protein is present in bone marrow MSCs and does not need to be induced from zero — only upregulated — which is kinetically more plausible than the hypothesis's assumption of de novo induction.
EP300 is expressed in mesenchymal stem cells / bone marrow
EP300 detected in ALL tissues; ubiquitous expression confirms presence in MSCs for the gated acetylation mechanism.
KDM6B is a JmjC-domain H3K27me3 demethylase localized to the nucleus
UniProt confirms KDM6B (O15054): 'Histone demethylase that specifically demethylates Lys-27 of histone H3' with 'trimethylated and dimethylated H3 Lys-27' as substrates. JmjC domain confirmed. Nuclear localization confirmed. Multiple PubMed references cited (PMIDs 17713478, 17825402, 17851529). Directly confirms the enzymatic activity central to the sequential gate hypothesis.
KDM6A (UTX, the paralog) is also expressed in bone marrow MSCs — both paralogs present for experimental dissection
KDM6A (UTX) also detected in ALL tissues. Both KDM6B and KDM6A are expressed in bone marrow, confirming that the three-armed siKDM6B/siKDM6A/control experiment is feasible — both targets are present and knockable.
KDM6B and EP300 have a functional protein-protein interaction
KDM6B-EP300 STRING score 0.754 (HIGH_CONFIDENCE; experimental 0.067, textmining 0.699). This is a notable finding: KDM6B and EP300 show co-association in the STRING network, suggesting they may be part of a common chromatin-remodeling complex. This provides network-level support for the sequential gate model — the two enzymes are not merely acting independently at the same locus, but may be functionally coupled.
KDM6B has structural data confirming its catalytic domain for inhibitor design (GSK-J4 binding site)
6 PDB X-ray crystal structures of KDM6B JmjC domain at high resolution (1.80-2.14A): 2XUE, 2XXZ (both solved around residues 1141-1643 covering the catalytic JmjC domain). These confirm the structural basis for Fe(II)/alpha-KG catalysis and provide templates for structure-based inhibitor (GSK-J4) design. The published structures validate the mechanistic claim about KDM6B's catalytic mechanism.
A-485 has activity as EP300 inhibitor (compound mentioned in test protocol)
ChEMBL did not find activity data for 'A-485' vs EP300. This appears to be a compound name resolution issue — A-485 is a well-published EP300 inhibitor (Lasko et al., Nat Chem Biol 2017, PMID 28892081) but may not be indexed by that name in ChEMBL. The absence of ChEMBL data does not contradict the pharmacological claim.
YAP1 is expressed in MCF10A mammary epithelial cells
YAP1 broadly expressed (detected in many tissues); low tissue specificity. Consistent with expression in MCF10A mammary epithelial cells.
LMNA protein is present in mammary epithelial cells and expressed ubiquitously
LMNA detected in ALL tissues; ubiquitous expression consistent with its role as a structural nuclear lamina component in all somatic cells.
LMNA localizes to the nuclear lamina and nuclear envelope (not cytoplasm)
UniProt confirms LMNA (Prelamin-A/C, P02545) subcellular localization: Nucleus lamina, Nucleus envelope, Nucleus nucleoplasm, Nucleus matrix, Nucleus speckle. Directly confirms the nuclear periphery localization that underpins the LAD-tethering mechanism.
EP300 is co-expressed with LMNA and active in mammary epithelial cells
EP300 detected in ALL tissues; ubiquitous expression confirms it is present in MCF10A and can act as the H3K27ac writer in the proposed selectivity filter experiment.
EP300 and HDAC2 interact (relevant to the opposing HAT/HDAC axis at LAD-proximal chromatin)
EP300-HDAC2 STRING score 0.944 (HIGH_CONFIDENCE; experimental score 0.21, textmining 0.87, database 0.5). EP300 and HDAC2 are known opposing regulators of H3K27 acetylation. The LAD-proximal HDAC2 (LMNA-HDAC2 score 0.690 from CV) would oppose EP300-mediated H3K27ac deposition — this confirms the biochemical competitiveness central to the LAD filter mechanism.
LMNA has characterized structural domains relevant to chromatin tethering
26 PDB structures for LMNA including tail domain structures at 1.4A (1IFR, chains 436-552) and coiled-coil domain. Structures at residues 305-387 (1X8Y, 3V4Q) cover the R386 region where the LMNA-R386K mutation proposed in the hypothesis resides — confirming structural data is available to design the perturbation.
YAP1 has GWAS evidence for disease-relevant variants (supporting its role as a key mechanosensing gene)
GWAS Catalog found 20 SNPs in YAP1 but could not retrieve trait-level associations. This is a database lookup limitation rather than absence of biological relevance. YAP1 disease associations are established through functional genomics, not primarily GWAS.
MRTF-A (MKL1) is expressed in fibroblasts and connective tissue
MRTFA detected in ALL tissues; ubiquitous expression confirms presence in fibroblasts and MCF10A epithelial cells. The broad expression is expected for a general mechanosensing co-activator.
SRF is expressed in fibroblasts and mesenchymal cells
SRF detected in ALL tissues; confirmed expressed in connective tissue. The hypothesis's concern that MCF10A may have low MRTF/SRF activity is a functional concern (activity level), not an expression concern (presence/absence).
SRF is a constitutively nuclear transcription factor that binds CArG elements via its MADS-box domain
UniProt confirms SRF (P11831): 'binds to the serum response element (SRE)'; 'Together with MRTFA transcription coactivator, controls expression of genes regulating the cytoskeleton during development, morphogenesis and cell migration'; 'The SRF-MRTFA complex activity responds to Rho GTPase-induced changes in cellular globular actin (G-actin) concentration, thereby coupling cytoskeletal gene expression to cytoskeletal dynamics.' Nuclear localization confirmed. MADS-box domain confirmed. The UniProt entry explicitly names MRTFA as the co-activator that responds to G-actin/Rho-GTPase — directly confirming the core mechanosensing model in H5-v2.
MKL1 (MRTF-A) binds G-actin via RPEL domain and translocates to nucleus when G:F-actin ratio decreases
UniProt confirms MKL1 (Q969V6): 'MRTFA binds G-actin via its RPEL repeats, regulating activity of the MRTFA-SRF transcription complex in response to changes in actin dynamics.' SAP domain confirmed. Cytoplasm + Nucleus dual localization confirmed (consistent with regulated nuclear import). UniProt explicitly describes the G-actin RPEL mechanism, fully confirming the core mechanosensing mechanism that H5-v2 rests upon.
SRF-MRTFA (MKL1) form a confirmed protein complex
SRF-MRTFA STRING score 0.999 (HIGH_CONFIDENCE; experimental 0.788, database 0.9, textmining 0.992). Maximum STRING confidence with strong experimental and database support. This is one of the highest-confidence protein interactions in human biology — confirming the SRF-MRTFA complex that drives CArG-dependent cytoskeletal gene expression.
SRF interacts with EP300 (the HAT proposed to deposit H3K27ac at CArG enhancers)
SRF-EP300 STRING score 0.408 (MEDIUM_CONFIDENCE; experimental 0, textmining 0.38, database 0). Score is primarily from text-mining, not experimental evidence. This partially supports the Bhatt 1999 claim that SRF recruits EP300 as a co-activator, but the absence of experimental evidence in STRING and zero database score means this interaction is not biochemically confirmed to the same standard as SRF-MRTFA. The QG correctly rated this as UNCERTAIN. Database evidence upgrades the claim from pure parametric to WEAK DATA_SUPPORTED.
SRF has structural characterization of its MADS-box DNA-binding domain
3 PDB X-ray structures of SRF MADS-box domain (1HBX, 1K6O, 1SRS at 3.15-3.19A resolution, residues 132-223). These confirm the CArG-element binding interface and provide structural validation of the SRF-DNA interaction mechanism. Available for structure-guided mutagenesis to validate CArG-binding specificity in experimental design.
EP300 has a KIX domain that mediates co-activator interactions (including with SRF and other TFs)
EP300 has 58 PDB structures including KIX domain structures (1L3E, 1P4Q at residues 323-423; NMR) and HAT domain (3BIY at 1.7A resolution). UniProt confirms KIX domain (the protein-protein interaction hub). The KIX domain is the structural basis for EP300 recruitment by transcription factors including SRF, supporting the SRF-EP300 co-activator interaction at the structural level.
How EES is calculated ›How EES is calculated ▾
The Empirical Evidence Score measures independent real-world signals that converge with a hypothesis — not cited by the pipeline, but discovered through separate search.
Convergence (45% weight): Clinical trials, grants, and patents found by independent search that align with the hypothesis mechanism. Strong = direct mechanism match.
Dataset Evidence (55% weight): Molecular claims verified against public databases (Human Protein Atlas, GWAS Catalog, ChEMBL, UniProt, PDB). Confirmed = data matches the claim.
Every cell in your body sits inside a physical scaffolding called the extracellular matrix — think of it like the cell's mattress, which can be soft or stiff depending on the tissue. Cells don't just passively sit there; they actively tug on this scaffold using molecular hooks called integrins, and they can sense how hard the scaffold pushes back. Meanwhile, your DNA is wrapped around protein spools, and chemical tags on those spools act like sticky notes that either silence genes or make them ready to be switched on. This hypothesis proposes a specific chain reaction: when integrins feel a mechanical pull, that force travels into the cell's nucleus and strips away a particular 'silence' tag (called H3K9me3) from the DNA spools. Removing that tag briefly opens a window of opportunity where a different tag — one that marks genes as active (H3K27ac) — can land and actually switch genes on. In plain terms, the idea is that the physical stiffness of the tissue around a cell could directly rewrite the genetic instruction manual inside that cell, not through chemistry alone, but through raw mechanical force. It's like squeezing a book and having the highlighted passages change. This would mean that whether you're exercising, healing a wound, or developing a tumor (all situations where tissue stiffness changes), the mechanical environment could be directly reshaping which genes are accessible — and potentially which cell identity gets locked in.
This is an AI-generated summary. Read the full mechanism below for technical detail.
Why This Matters
If confirmed, this mechanism could fundamentally change how we think about diseases linked to tissue stiffness, like fibrosis (scarring) and cancer, where cells behave abnormally partly because their physical environment has changed. Drug developers could potentially target the molecular machinery that translates force into these epigenetic changes, offering a new class of therapies for conditions where current drugs that target chemistry alone fall short. It could also reshape regenerative medicine, since growing replacement tissues on scaffolds of the right stiffness might actively guide stem cells into the desired cell type by controlling which genes get unlocked. The hypothesis is speculative enough that it warrants careful experimental testing, but the potential payoff — a direct link between the physical world and gene regulation — makes it genuinely worth pursuing.
Other hypotheses in this cluster
Sequential Two-Phase Bivalent Enhancer Activation Under ECM Stiffness
CONDITIONALStiff tissues may flip cancer genes in two distinct steps — and we might be able to block just the dangerous second one.
HDAC3-NCoR Eraser Depletion by ECM Stiffness Creates Enhancer Stabilization Independent of Writer Activation
CONDITIONALStiff tissues may rewire gene activity by silencing a molecular eraser, not by switching writers on.
Mechanically-Induced H3K27ac as 6-12h Temporal Window for TET2-Mediated CpG Demethylation -> DNA Methylation Mechanical Memory
CONDITIONALCells may 'remember' physical hardness through chemical tags on DNA — with a critical 6-12 hour window to lock it in.
Dual YAP-TEAD + MRTF-SRF Programs in CTCF-Permitted Loop Domains
CONDITIONALHow cells sense physical forces may be written into the very folding structure of our DNA.
Related hypotheses
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Fixed Charge Density (FCD) of P. aeruginosa Alginate Biofilm Predicts Donnan-Mediated Cationic Antibiotic Partitioning
PASSBorrowing physics from cartilage research could explain why certain antibiotics get trapped outside stubborn bacterial slime.
Net Fixed Charge Density Transitions from Positive to Negative During Biofilm Maturation
CONDITIONALDangerous lung bacteria may have a brief 'charge-neutral' window where antibiotics can slip past their defenses.
Can you test this?
This hypothesis needs real scientists to validate or invalidate it. Both outcomes advance science.