TAK1 (MAP3K7)

TAK1 (TGF-beta-activated kinase 1; gene MAP3K7) is a serine/threonine kinase of the MAP3K (MAPK kinase kinase) family that functions as a critical convergence node integrating inflammatory and stress signals — from IL-1R/TLR, TNF-R, TGF-β, and BMP receptors — into two parallel downstream outputs: NF-κB activation (via IKK/NEMO) and MAPK activation (via JNK/p38 through MKK4/7 and MKK3/6). In the aging context, TAK1 is the MAP3K that bridges traf6-assembled K63-polyubiquitin scaffolds to the NF-κB transcriptional programme driving inflammaging and SASP maintenance.

TAK1 is the fourth adaptor-to-effector hand-off in the canonical il-1-signaling cascade: IL-1R1/IL-1RAcP → myd88 → irak4 → traf6 → TAK1 → IKK/MAPK. This page covers the protein biology; pathway-level context lives on il-1-signaling (verified R27).

Identity

Field	Value
UniProt	O43318 (MAP3K7_HUMAN)
NCBI Gene	6885
HGNC	6859
Ensembl	ENSG00000135341
Length	606 aa (canonical isoform)
Organism	Homo sapiens
Mouse ortholog	Map3k7 (one-to-one; high conservation)

Domain architecture

TAK1 has three functional regions ¹:

Region	Residues (approx.)	Function
Protein kinase domain	36–291	Catalytic core; ATP-binding pocket; site of covalent (5Z-7-oxozeaenol) and competitive (Takinib) inhibitors
Linker / regulatory	292–400	Disordered; mediates protein-protein interactions
C-terminal domain	400–606	TAB1/TAB2/TAB3 binding; coiled-coil elements; required for complex formation and membrane recruitment

Key post-translational modifications:

Thr187 — activation loop autophosphorylation; required for catalytic activity; dephosphorylated by PP2A and PPP6C ¹
Ser192 and Thr184 — additional regulatory phosphorylation sites
K63-linked polyubiquitin attachment (non-degradative) — promotes TAK1 complex activation upon TRAF6 engagement ²

TAB co-regulatory complex

TAK1 does not act alone in cells. It constitutively associates with three TAB (TAK1-binding) proteins that govern its activation:

Subunit	Gene	UniProt	Role
TAB1	TAB1	Q15653	Constitutive allosteric activator; binds C-terminal TAK1 domain; promotes basal Thr187 autophosphorylation
TAB2	TAB2	O43150	K63-polyubiquitin reader (NZF zinc-finger domain); links TRAF6-assembled ubiquitin chains to TAK1 complex
TAB3	TAB3	Q9Y4C0	Functionally redundant with TAB2; NZF domain K63-ubiquitin sensor; alternative K63-ubiquitin docking subunit

TAB2 and TAB3 are mutually exclusive alternatives in the complex for K63-ubiquitin sensing; TAB1 is a constitutive member. Wang 2001 ² demonstrated that immunodepletion of TAB2 from HEK-293 cell extracts abolished TRAF6-dependent IKK activation, and that recombinant TAK1-TAB1-TAB2 complex is the minimal unit sufficient for IKK activation. TAB3 and its functional redundancy with TAB2 for K63-ubiquitin sensing were characterized in subsequent studies; the TAB2/TAB3 double-knockout phenotype (abolishing TAK1 activation downstream of IL-1R and TLR) was established by Ishitani et al. 2003 and related work. needs-replication — the double-KO data are from non-human cell systems.

Activation mechanism (IL-1/TLR arm)

In the IL-1R/TLR signalling context, TAK1 activation proceeds through a ubiquitin-scaffolding mechanism ² ³:

traf6 (E3 ubiquitin ligase) assembles K63-linked polyubiquitin chains on itself and IRAK1 upon receptor complex activation.
The NZF zinc-finger domain of TAB2 or TAB3 recognizes and binds K63-polyubiquitin chains — recruiting the TAK1·TAB1·TAB2/3 complex to the receptor signalosome at the membrane periphery.
Proximity to the ubiquitin scaffold triggers trans-autophosphorylation of Thr187 in the activation loop.
Activated TAK1 then phosphorylates downstream substrates: IKKβ (Ser177/Ser181) in the NF-κB arm and MKK4/7 and MKK3/6 in the MAPK arm (below).

This ubiquitin-dependent kinase activation mechanism is well established ² and represents a paradigm for non-degradative K63-ubiquitin signalling. Critically, the kinase activity depends on ubiquitin scaffolding: TAK1 is inactive as a monomer and requires TAB1 for basal autophosphorylation competence and TAB2/TAB3 for stimulus-coupled membrane recruitment.

Dimension	Status
Pathway conserved in humans?	yes — TAK1, TAB1/2/3 all human-described; NF-κB/MAPK outputs human-validated
Phenotype conserved in humans?	yes — IL-1-driven NF-κB/inflammaging conserved (CANTOS, n=10,061) ⁴
Replicated in humans?	partial — NF-κB arm validated; TAK1-specific human genetics via FMD2 gain-of-function mutations ⁵

NF-κB arm

TAK1 phosphorylates IKKβ at Ser177 and Ser181, activating the trimeric IKK complex (IKKα/IKKβ/NEMO). Active IKK then phosphorylates IκBα at Ser32/Ser36, targeting it for proteasomal degradation. This releases NF-κB dimers (predominantly p65/p50) to translocate to the nucleus and drive transcription of pro-inflammatory cytokines (IL-1β, IL-6, IL-8, TNF-α), chemokines, adhesion molecules, and SASP components ² ³.

TAK1’s role in IL-1-driven NF-κB activation was definitively established by Sato et al. (2005): TAK1-deficient mouse embryonic fibroblasts (TAK1-/- MEFs) completely failed to activate NF-κB or MAPKs in response to IL-1β and TNF-α, demonstrating that TAK1 is non-redundant in this cascade ³. needs-replication — this was demonstrated in MEFs; cell-type-specific dependencies in human immune or senescent cells require separate validation.

MAPK arm

In parallel with the NF-κB arm, TAK1 activates two MAPK kinase (MKK) branches ²:

MKK4 and MKK7 → JNK (c-Jun N-terminal kinase) → AP-1 transcriptional activation; mRNA stabilization of inflammatory genes (via ARE elements)
MKK3 and MKK6 → p38 MAPK → inflammatory gene transcription, cytokine mRNA stabilization, MAPKAP-K2 (MK2) activation → additional post-transcriptional inflammatory output

The dual NF-κB + MAPK output makes TAK1 a signal amplifier rather than a binary switch: inflammatory transcriptional responses (NF-κB) are reinforced by post-transcriptional stabilization of cytokine mRNAs (MAPK/MK2 arm), creating a co-amplified inflammatory gene expression program.

TGF-β/BMP arm

Beyond IL-1/TLR signalling, TAK1 is also activated downstream of TGF-β and BMP receptors — the pathway for which it was originally named ¹. In this context, receptor-activated Smads recruit TAB1 and the TAK1 complex independently of TRAF6-K63 ubiquitin chains. The TGF-β/TAK1/MKK4/JNK axis contributes to myofibroblast activation, fibrosis, and apoptosis in various tissue contexts. This arm may be relevant to age-associated fibrosis but is less well studied in the aging context than the IL-1/TLR arm. no-mechanism

Aging connection

Inflammaging via chronic TAK1 activation

Chronic low-level activation of the IL-1 → TRAF6 → TAK1 → NF-κB axis is a central driver of inflammaging — the persistent, low-grade sterile inflammation characteristic of aged tissue. TAK1 is the MAP3K that transduces K63-polyubiquitin signals from TRAF6 into the NF-κB transcriptional programme, placing it mechanistically upstream of the major inflammaging effectors (IL-1β, IL-6, TNF-α).

TAK1 in SASP maintenance

Senescent cells sustain their own SASP through an IL-1α autocrine loop: cell-surface IL-1α on senescent cells signals through IL-1R → NF-κB → SASP cytokine transcription, including IL-6 and IL-8, in a feed-forward manner ⁶. Because TAK1 is the MAP3K required for IL-1R-driven NF-κB activation (established by Sato 2005 ³ in MEFs), it is mechanistically positioned as the kinase that would sustain this autocrine loop in senescent cells. However, direct genetic evidence that TAK1 specifically (vs IKK directly) maintains tonic NF-κB in human senescent cells has not been published. This is an inference from pathway architecture. unsourced — the claim requires a dedicated experiment (TAK1 KO in senescent human fibroblasts with SASP quantification) to be directly sourced.

Separately, Acosta et al. 2013 ⁷ described a paracrine senescence program orchestrated by the inflammasome (including IL-1β secretion), which is mechanistically related but distinct from the autocrine IL-1α loop. The senescent retinal pigment epithelium (RPE) model provides supporting evidence for TAK1’s role in senescence-driven inflammation: TAK1/p38 MAPK is activated by senescent RPE cells and pharmacological TAK1 inhibition with 5Z-7-oxozeaenol or Takinib suppresses pathological angiogenesis in a senescence-driven choroidal neovascularization model ⁸. needs-replication — these are rat/cell models; human validation absent.

Dimension	Status
Pathway conserved in humans?	yes — TAK1/NF-κB axis conserved; SASP mechanism conserved across human fibroblasts and epithelial cells
Phenotype conserved in humans?	partial — SASP-maintenance loop mechanistically described in human cells; TAK1-specific dependency not genetically confirmed in human senescent cells
Replicated in humans?	no — TAK1 role in SASP maintenance demonstrated in cell models; no human aging intervention study

Cardiac aging

TAK1 has been studied in the cardiac aging context through genetic models. Conditional cardiomyocyte-specific Map3k7 deletion (cKO) in mice produces spontaneous apoptosis and necroptosis in cardiomyocytes, leading to adverse remodeling and heart failure, establishing that baseline TAK1 activity is required for normal cardiomyocyte survival — a finding that complicates the therapeutic picture ⁹. Conversely, TAB1-driven TAK1 activation drives pathological cardiac hypertrophy: RNF207-mediated K63-ubiquitination of TAB1 activates TAK1 → p38/JNK in pressure overload-induced hypertrophy, and RNF207 knockdown blunts cardiac remodeling in transverse aortic constriction (TAC) mouse models ¹⁰. needs-human-replication — these are mouse models; translation to human cardiac aging is not established.

Pharmacology

TAK1 has been pursued as a therapeutic target for inflammatory and autoimmune disease for over 20 years, resulting in two well-characterized chemical probes but no FDA-approved agent.

5Z-7-oxozeaenol (covalent inhibitor)

A resorcylic acid lactone natural product derived from the fungus Oomycete. Binds covalently to Cys174 in the TAK1 ATP-binding pocket (irreversible, electrophilic Michael acceptor). Inhibits TAK1 with IC50 in the low nanomolar range ¹¹. Mechanism: 5Z-7-oxozeaenol blocked IL-1-induced TAK1 autophosphorylation, JNK/p38 activation, IκB kinase activation, and NF-κB nuclear translocation, and suppressed COX-2 production in treated cells ¹¹. Widely used as a research tool. Not suitable for clinical development due to irreversibility, poor selectivity across the kinome (multiple off-targets with reactive cysteines), and lack of pharmacokinetic properties.

Takinib (reversible ATP-competitive inhibitor)

A selective, reversible, ATP-competitive small-molecule TAK1 inhibitor developed to address the selectivity problems of 5Z-7-oxozeaenol ¹². Totzke et al. (2017) demonstrated that Takinib shows a narrow selectivity profile against a panel of 340 kinases and broadens the therapeutic window of TNF-α inhibition in cancer and autoimmune disease models. Has been tested in combination with TNF pathway blockade. long-term-unknown — no clinical agent has yet advanced to Phase 1 for any indication. Selectivity across the kinome at pharmacologically relevant concentrations remains an open question for in vivo use.

No aging-specific clinical agent

Despite two decades of probe development, no TAK1 inhibitor has entered clinical trials for aging, inflammatory disease, or SASP-related indications as of 2026. The primary barrier is the dual role of TAK1: it is required for normal immune signalling (TAK1-/- mice are embryonic lethal) and for cardiomyocyte survival, meaning that non-selective systemic inhibition risks immunosuppression and cardiac toxicity. Tissue-specific or senescence-context-specific approaches would be needed to unlock therapeutic utility in aging. Druggability tier 2 (R27 aging-context convention): high-quality probes exist; no aging-validated clinical drug.

Disease genetics

Frontometaphyseal dysplasia type 2 (FMD2) — gain-of-function missense mutations in MAP3K7 cause this X-linked skeletal dysplasia characterized by supraorbital hyperostosis, joint contractures, and mixed hearing loss ⁵. The causative mutations cluster in the kinase domain or near regulatory sites, constitutively increasing TAK1 kinase activity and downstream NF-κB/MAPK output. This genetic evidence confirms that chronic TAK1 hyperactivation is pathological in humans — directly relevant to the inflammaging hypothesis, where TAK1 is chronically but less severely activated. No aging-specific gain-of-function MAP3K7 GWAS signal has been reported. needs-population-data

Key interactors

traf6 — E3 ubiquitin ligase; primary upstream activator in IL-1/TLR arm; assembles K63-ubiquitin scaffold recognized by TAB2/TAB3
tab1 — constitutive allosteric activator (complex-subunit; not seeded yet)
myd88 — upstream adaptor linking TIR-domain receptors to IRAK4 → TRAF6 → TAK1 cascade
irak4 — proximal kinase activating TRAF6 before TAK1 in the IL-1R/TLR cascade
nf-kb — primary downstream transcriptional target (via IKKβ phosphorylation)
ras-mapk — MAPK arm output (JNK via MKK4/7; p38 via MKK3/6)
il-1-signaling — the integrating pathway page for full cascade context (verified R27)

Notes on causal-graph entries

The caused-by: frontmatter entries reflect three distinct TAK1 activation mechanisms:

traf6 — primary upstream activator in the IL-1/TLR arm; TRAF6 assembles K63-polyubiquitin chains recognized by TAB2/TAB3 NZF zinc-finger domains, recruiting the TAK1 complex to the receptor signalosome ²
tab1 — constitutive allosteric activator; TAB1 binds the TAK1 C-terminal domain and promotes basal Thr187 autophosphorylation independently of stimulus ¹
tgf-beta-signaling — the pathway for which TAK1 was originally named; receptor-activated Smads recruit the TAK1 complex independently of TRAF6/K63-ubiquitin ¹

Cross-references

il-1-signaling — verified pathway page (R27); cascade diagram and biological context
traf6 — immediate upstream activator (R28 sibling page)
myd88 — upstream adaptor (R28 sibling page)
irak4 — upstream kinase (R28 sibling page)
nf-kb — downstream transcriptional effector
ras-mapk — downstream MAPK arm
chronic-inflammation — hallmark driven by TAK1-dependent NF-κB output
sasp — functional output; TAK1 maintains SASP via NF-κB in senescent cells
cellular-senescence — context in which TAK1 autocrine loop sustains SASP

Limitations and gaps

GTEx aging correlation: gtex-aging-correlation not retrieved — requires GTEx v2 API lookup (sops/finding-tissue-expression.md). needs-population-data
MR evidence: No published Mendelian randomization study using MAP3K7 germline instruments for aging-related outcomes. needs-population-data
GenAge entry: TAK1 not currently in GenAge human aging gene database; entry should be verified on next lint pass. needs-canonical-id
SASP maintenance role: The IL-1α autocrine loop that TAK1 is positioned to sustain has its primary source in Orjalo 2009 (PNAS; IL-1α as upstream regulator of SASP IL-6/IL-8). Acosta 2013 (Nat Cell Biol, 10.1038/ncb2784) covers paracrine senescence via the inflammasome — a related but distinct mechanism. Direct genetic evidence that TAK1 specifically (vs IKK directly) maintains NF-κB in human senescent cells has not been published. unsourced — claim requires dedicated experiment.
Cardiac aging genetics: The cardiac TAK1 cKO phenotype (spontaneous apoptosis/necroptosis → heart failure) is sourced to Li et al. 2014 Circulation (10.1161/CIRCULATIONAHA.114.011195). The seeder’s reference to “Liu 2013 Cell Death Dis” was incorrect; the correct paper is Li 2014 with Qinghang Liu as corresponding author.
TAK1 vs IKK selectivity for aging: Whether targeting TAK1 upstream vs IKK directly provides better aging-context selectivity is unresolved. Different selectivity profiles across cell types and stimulus contexts remain incompletely mapped. no-mechanism
TGF-β arm in aging fibrosis: TAK1’s role in age-associated fibrosis via the TGF-β/BMP arm is not well characterized; mechanism not established. no-mechanism
WikiPathways ID for TGF-β signaling: [[tgf-beta-signaling]] wikilink is an implicit stub — no pathways/tgf-beta-signaling.md page exists yet.

Footnotes

UniProt O43318 (MAP3K7_HUMAN), accessed 2026-05-07 · Swiss-Prot manually curated · 606 aa · kinase domain 36–291 · Thr187 activation loop phosphorylation · TAB1/2/3 binding C-terminal domain ↩ ↩² ↩³ ↩⁴ ↩⁵
doi:10.1038/35085597 · Wang C et al. · Nature 2001 · in-vitro (reconstitution, HEK-293 cell extracts, co-immunoprecipitation, kinase assay) · demonstrated TAK1 is activated as a ubiquitin-dependent kinase by K63-polyubiquitin chains assembled by TRAF6+Ubc13-Uev1A; TAB2 (NZF zinc-finger domain) acts as the ubiquitin receptor subunit; TAK1-TAB1-TAB2 (TRIKA2) is the minimal IKK-activating complex; K63 lysine is necessary and sufficient for ubiquitin-mediated TAK1 activation; TAK1 phosphorylates IKKβ at Ser177/Ser181 and MKK6 at Ser207/Thr211 · NB: TAB3 not described in this paper — double-KO phenotype is from subsequent work · local PDF: (local PDF) ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷
doi:10.1038/ni1255 · Sato S et al. (Akira lab) · Nature Immunology 2005 · in-vivo + in-vitro (TAK1 conditional KO mice, TAK1-/- MEFs) · TAK1-deficient cells completely failed to activate NF-κB or MAPKs in response to IL-1β and TNF; TAK1 is non-redundant in innate and adaptive immune signalling · 963 citations · not locally available (not_oa) ↩ ↩² ↩³ ↩⁴
Cross-reference to il-1-signaling (verified R27) and canakinumab for CANTOS trial numerics: doi:10.1056/NEJMoa1707914 · Ridker PM et al. · NEJM 2017 · rct · n=10,061 · canakinumab 150 mg HR 0.85 (95% CI 0.74–0.98) for MACE; establishes IL-1 → NF-κB axis as causally relevant in human cardiovascular aging ↩
doi:10.1016/j.ajhg.2016.05.024 · Wade EM & Robertson SP · Am J Hum Genet 2016 · human genetics (clinical genetics cohort) · MAP3K7 gain-of-function missense mutations cause Frontometaphyseal Dysplasia type 2; mutations cluster in kinase domain and constitutively hyperactivate TAK1 → NF-κB/MAPK · 68 citations · not locally available (bronze OA, pending download) ↩ ↩²
doi:10.1073/pnas.0905299106 · Orjalo AV et al. (Campisi lab) · PNAS 2009 · in-vitro (human senescent fibroblasts) · cell surface-bound IL-1α is an upstream regulator of the senescence-associated IL-6/IL-8 cytokine network; blocking IL-1 receptor signalling suppresses SASP IL-6/IL-8 secretion · model: human IMR-90 and BJ fibroblasts · primary source for the IL-1α autocrine loop in SASP maintenance ↩
doi:10.1038/ncb2784 · Acosta JC et al. (Gil lab) · Nature Cell Biology 2013 · in-vivo + in-vitro · inflammasome-orchestrated complex secretory programme controls paracrine senescence (spread of senescence to neighbouring cells); IL-1β and IL-18 are key inflammasome outputs · PMID: 23770676 · NB: this paper covers paracrine senescence, not the IL-1α autocrine loop; do not conflate. ↩
doi:10.1016/j.exer.2025.110232 · Wang Y et al. · Exp Eye Res 2025 · in-vivo (laser-induced CNV rat model) + in-vitro (senescent RPE cells) · TAK1/p38 MAPK activated by senescent RPE cells drives pathological angiogenesis; 5Z-7-oxozeaenol and Takinib inhibited lesion formation and improved retinal function · 5 citations · not locally available ↩
doi:10.1161/CIRCULATIONAHA.114.011195 · Li L, Chen Y, Doan J, Murray J, Molkentin JD, Liu Q · Circulation 2014 · in-vivo (cardiac-specific Map3k7 cKO mouse) · cardiac-specific ablation of Map3k7 induces spontaneous cardiomyocyte apoptosis and necroptosis → adverse remodeling → heart failure; TAK1 is required for myocardial survival · model: C57BL/6 background · needs-human-replication ↩
doi:10.1093/cvr/cvad017 · Yuan L et al. · Cardiovascular Research 2023 · in-vivo (mouse TAC model) + in-vitro · RNF207 promotes K63-ubiquitination of TAB1, activating TAK1 → p38/JNK → pathological cardiac hypertrophy; RNF207 knockdown blunts cardiac remodeling · model: C57BL/6 TAC mice · needs-human-replication ↩
doi:10.1074/jbc.M207453200 · Ninomiya-Tsuji J et al. · J Biol Chem 2003 · in-vitro + in-vivo (cell-based assays, mouse model) · 5Z-7-oxozeaenol identified as covalent TAK1 inhibitor; blocked IL-1-induced TAK1 autophosphorylation, JNK/p38 activation, IκB kinase activation, NF-κB translocation, and COX-2 production · 416 citations · not yet locally downloaded (pending) ↩ ↩²
doi:10.1016/j.chembiol.2017.07.011 · Totzke J et al. · Cell Chem Biol 2017 · in-vitro + in-vivo (340-kinase selectivity panel; TNF model) · Takinib is a selective, reversible, ATP-competitive TAK1 inhibitor; broadens efficacy of TNF-α inhibition in cancer and autoimmune disease models · 126 citations · not yet locally downloaded (pending); OA bronze ↩

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