WWTR1 (TAZ) — WW Domain Containing Transcription Regulator 1, Hippo Effector

WWTR1 (TAZ) — WW Domain Containing Transcription Regulator 1, Hippo Effector

<div class="infobox infobox-gene">
<h3>WWTR1 (TAZ)</h3>
<table>
<tr><td><strong>Full Name</strong></td><td>WW Domain Containing Transcription Regulator 1</td></tr>
<tr><td><strong>Gene Symbol</strong></td><td>WWTR1 (TAZ)</td></tr> [@mao2021]
<tr><td><strong>Chromosomal Location</strong></td><td>3q25.1</td></tr> [@dupont2011]
<tr><td><strong>NCBI Gene ID</strong></td><td>[25937](https://www.ncbi.nlm.nih.gov/gene/25937)</td></tr> [@panciera2017]
<tr><td><strong>OMIM</strong></td><td>[607392](https://omim.org/entry/607392)</td></tr> [@rao2018]
<tr><td><strong>Ensembl</strong></td><td>[ENSG00000018408](https://ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000018408)</td></tr> [@fan2022]
<tr><td><strong>UniProt (Protein)</strong></td><td>[Q9GZV5 (WW domain-containing transcription regulator 1)](https://www.uniprot.org/uniprot/Q9GZV5)</td></tr> [@zheng2019]
<tr><td><strong>Associated Diseases</strong></td><td>[Alzheimer's Disease](/diseases/alzheimers-disease), [Parkinson's Disease](/diseases/parkinsons-disease), [ALS](/diseases/amyotrophic-lateral-sclerosis), Glioblastoma</td></tr>
</table>
</div>

Overview

WWTR1 (TAZ) — WW Domain Containing Transcription Regulator 1, Hippo Effector

<div class="infobox infobox-gene">
<h3>WWTR1 (TAZ)</h3>
<table>
<tr><td><strong>Full Name</strong></td><td>WW Domain Containing Transcription Regulator 1</td></tr>
<tr><td><strong>Gene Symbol</strong></td><td>WWTR1 (TAZ)</td></tr> [@mao2021]
<tr><td><strong>Chromosomal Location</strong></td><td>3q25.1</td></tr> [@dupont2011]
<tr><td><strong>NCBI Gene ID</strong></td><td>[25937](https://www.ncbi.nlm.nih.gov/gene/25937)</td></tr> [@panciera2017]
<tr><td><strong>OMIM</strong></td><td>[607392](https://omim.org/entry/607392)</td></tr> [@rao2018]
<tr><td><strong>Ensembl</strong></td><td>[ENSG00000018408](https://ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000018408)</td></tr> [@fan2022]
<tr><td><strong>UniProt (Protein)</strong></td><td>[Q9GZV5 (WW domain-containing transcription regulator 1)](https://www.uniprot.org/uniprot/Q9GZV5)</td></tr> [@zheng2019]
<tr><td><strong>Associated Diseases</strong></td><td>[Alzheimer's Disease](/diseases/alzheimers-disease), [Parkinson's Disease](/diseases/parkinsons-disease), [ALS](/diseases/amyotrophic-lateral-sclerosis), Glioblastoma</td></tr>
</table>
</div>

Overview

WWTR1 (WW Domain Containing Transcription Regulator 1), commonly known as TAZ (transcriptional co-activator with PDZ-binding motif), encodes a 400 amino acid transcriptional co-activator that functions as a central effector of the Hippo signaling pathway. TAZ is the paralog of [YAP1](/genes/yap1), and together they constitute the primary nuclear output of Hippo signaling. When the Hippo pathway is inactive (low [LATS1](/genes/lats1)/[LATS2](/genes/lats2) activity), TAZ accumulates in the nucleus, where it binds TEAD transcription factors and drives expression of genes controlling proliferation, survival, stemness, and mechanotransduction. In the nervous system, TAZ plays critical roles in astrocyte reactivity, neural stem cell maintenance, oligodendrocyte myelination, and neuronal survival, with its dysregulation increasingly linked to neurodegeneration and brain tumors.

Note: WWTR1/TAZ should not be confused with TAFAZZIN (also abbreviated TAZ), encoded by the TAFAZZIN gene on the X chromosome, which is involved in cardiolipin remodeling and Barth syndrome.

Gene Structure and Expression

WWTR1 spans approximately 100 kb on chromosome 3q25.1 and contains 7 exons. The promoter is regulated by multiple transcription factors including [CREB](/genes/creb1), AP-1 ([FOS](/genes/fos)/[JUN](/genes/jun)), and TEADs themselves (creating a positive autoregulatory loop). Epigenetic regulation via [HDAC](/genes/hdac1)-mediated deacetylation and [DNA methylation](/entities/dna-methylation) modulates TAZ expression in a tissue-specific manner.

In the developing brain, TAZ is broadly expressed in neural progenitor cells, with high levels in the ventricular zone and subventricular zone. In the adult brain, TAZ expression is prominent in [astrocytes](/cell-types/astrocytes), [oligodendrocytes](/cell-types/oligodendrocytes), and [neural stem cells](/cell-types/neural-stem-cells) of the SVZ and SGZ, with lower but detectable levels in mature [neurons](/entities/neurons). The [Allen Brain Atlas](https://human.brain-map.org/) shows moderate expression across the [cortex](/brain-regions/cortex), [hippocampus](/brain-regions/hippocampus), and white matter tracts, with enrichment in glia-rich regions.

Protein Function and Mechanism

TAZ is a 400 amino acid protein containing a TEAD-binding domain (TBD) at the N-terminus, a single WW domain that recognizes PPxY motifs, a coiled-coil domain, a transcriptional activation domain (TAD), and a C-terminal PDZ-binding motif (absent in YAP). These structural features enable TAZ to integrate upstream Hippo signals with diverse transcriptional programs.

Transcriptional Co-Activation

TAZ lacks intrinsic DNA-binding ability and functions exclusively as a transcriptional co-activator. Its primary transcription factor partners are the TEAD family (TEAD1-4), with additional interactions with:

• RUNX2/3: Regulates osteogenic and chondrogenic differentiation
• TBX5: Cardiac development; mutations disrupting TAZ–TBX5 interaction cause congenital heart defects
• SMAD2/3: Integrates [TGF-β](/genes/tgfb1) signaling with Hippo pathway output
• PAX3/8: Neural crest specification
• [NF-κB](/entities/nf-kb) subunits: TAZ co-activates NF-κB-dependent inflammatory gene expression in [astrocytes](/entities/astrocytes) and [microglia](/cell-types/microglia-neuroinflammation)

Regulation by the Hippo Kinase Cascade

TAZ activity is controlled by a phosphorylation-dependent cytoplasmic–nuclear shuttling mechanism:

Mechanotransduction

TAZ is a critical mechanosensor that translates extracellular matrix (ECM) stiffness into transcriptional responses. On stiff substrates, cytoskeletal tension through actomyosin contractility (Rho–ROCK pathway) inhibits LATS1/2 and promotes TAZ nuclear entry. On soft substrates (mimicking the soft brain parenchyma), LATS1/2 are active and TAZ is excluded from the nucleus. This mechanosensing function is particularly relevant in the brain, where:

• ECM stiffness increases with age and in neurodegeneration (amyloid plaques, gliosis)
• Reactive astrocytes stiffen their surroundings, potentially creating aberrant TAZ activation in nearby cells
• Neural stem cell fate decisions (neurogenesis vs. gliogenesis) are influenced by niche stiffness via TAZ

TAZ vs. YAP: Functional Divergence

While TAZ and [YAP1](/genes/yap1) share ~50% sequence identity and are often functionally redundant, important differences exist:

• TAZ has one WW domain (YAP has two), narrowing its protein–protein interaction repertoire
• TAZ contains a unique C-terminal PDZ-binding motif enabling interactions with PDZ-domain proteins (e.g., zonula occludens ZO-1/2)
• TAZ is preferentially expressed in glia (astrocytes, oligodendrocytes), while YAP is more abundant in neurons
• TAZ knockout mice are viable but develop polycystic kidney disease; YAP knockout is embryonic lethal at E8.5

Role in Neural Development and Glia

TAZ plays distinctive roles in glial cell biology and neural development:

• Astrocyte reactivity: TAZ is the dominant YAP/TAZ paralog in astrocytes. Nuclear TAZ–TEAD drives the reactive astrocyte transcriptional program, including upregulation of [GFAP](/genes/gfap), [vimentin](/genes/vim), and [STAT3](/genes/stat3) target genes. TAZ promotes the A2 (neuroprotective) reactive phenotype over the A1 (neurotoxic) phenotype by co-activating anti-inflammatory gene programs
• Oligodendrocyte myelination: TAZ is essential for [oligodendrocyte precursor cell (OPC)](/cell-types/oligodendrocyte-precursor-cells) differentiation and myelination. TAZ–TEAD complexes activate myelin gene transcription ([MBP](/genes/mbp), [PLP1](/genes/plp1), [MAG](/genes/mag)) and suppress inhibitory signals ([ID2](/genes/id2), [HES1](/genes/hes1)). Conditional TAZ deletion in oligodendrocyte lineage cells causes hypomyelination
• Neural stem cell maintenance: TAZ maintains the proliferative capacity of adult neural stem cells in the SVZ and SGZ. TAZ loss reduces neurosphere formation and impairs adult neurogenesis
• Ependymal cell ciliogenesis: TAZ regulates multi-ciliogenesis in ependymal cells lining the brain ventricles, and its deficiency causes hydrocephalus in mice

Disease Associations

Alzheimer's Disease (AD)

TAZ is dysregulated in [AD](/diseases/alzheimers-disease) in a cell-type-specific manner. In hippocampal neurons, [Aβ](/proteins/amyloid-beta)-induced oxidative stress activates the MST1–LATS1 cascade, leading to TAZ phosphorylation and degradation. Loss of nuclear TAZ deprives neurons of TEAD-dependent survival gene expression, contributing to [apoptosis](/entities/apoptosis). In reactive astrocytes surrounding amyloid plaques, however, TAZ is paradoxically upregulated — driven by ECM stiffening from plaque deposition and [TGF-β](/genes/tgfb1) signaling. Astrocytic nuclear TAZ drives the reactive astrogliosis program but may have both protective (scar formation, Aβ phagocytosis) and detrimental (chronic inflammation, synaptic stripping) consequences depending on disease stage.

[Tau](/genes/mapt) pathology further perturbs TAZ signaling: neurofibrillary tangles disrupt cytoskeletal tension and mechanotransduction, leading to aberrant TAZ activation in tangle-bearing neurons. TAZ overexpression in [tau](/proteins/tau)-expressing neuronal models modulates [GSK-3β](/genes/gsk3b) activity and paradoxically reduces tau phosphorylation at certain epitopes (AT8, PHF-1), suggesting a complex feedback relationship.

Parkinson's Disease (PD)

In [PD](/diseases/parkinsons-disease) models, [α-synuclein](/entities/snca) aggregation activates MST1, which phosphorylates LATS1/2 and leads to TAZ degradation in dopaminergic neurons. TAZ loss impairs mitochondrial quality control by reducing transcription of mitophagy regulators, exacerbating the [PINK1](/genes/pink1)/[Parkin](/genes/prkn) pathway deficiency characteristic of PD. Astrocytic TAZ is protective in PD: TAZ-positive reactive astrocytes in the substantia nigra upregulate [GDNF](/genes/gdnf) and [BDNF](/genes/bdnf), providing trophic support to surviving dopaminergic neurons. Conditional TAZ deletion in astrocytes worsens MPTP-induced dopaminergic neuron loss in mice.

Amyotrophic Lateral Sclerosis (ALS)

TAZ expression is reduced in motor neurons of [ALS](/diseases/amyotrophic-lateral-sclerosis) patients and SOD1-G93A mice. Nuclear TAZ normally sustains expression of [TEAD4](/genes/tead4)-dependent genes involved in motor neuron identity and axonal maintenance. TAZ degradation via LATS1-dependent phosphorylation correlates with motor neuron degeneration. In ALS astrocytes, TAZ dynamics are altered: reactive astrocytes show increased nuclear TAZ, which drives the neuroinflammatory program including [C3](/genes/c3) complement upregulation — a hallmark of neurotoxic A1 astrocytes in ALS.

Glioblastoma

TAZ is frequently overexpressed or amplified in glioblastoma (GBM), particularly in the mesenchymal subtype. Nuclear TAZ–TEAD drives expression of mesenchymal transition genes, invasion-related genes ([MMP2](/genes/mmp2), MMP9), and stem cell maintenance factors ([CD44](/genes/cd44), [SOX2](/genes/sox2)). TAZ amplification at 3q25.1 is an independent poor prognostic factor in GBM. Conversely, LATS1/2-mediated TAZ inactivation suppresses GBM stem cell self-renewal, making the LATS1–TAZ axis a therapeutic target.

Common Variants

| Variant | Type | Association | Reference |
|---------|------|-------------|-----------|
| rs3811715 | Intronic | Nominal association with brain volume | [Genome-wide studies](https://www.ebi.ac.uk/gwas/) |
| 3q25.1 amplification | Copy number gain | GBM mesenchymal subtype, poor prognosis | [Bhat et al., 2011](https://doi.org/10.1016/j.ccr.2011.03.022) |
| c.475C>T (R159W) | Missense | Reduced TEAD binding, benign variant | [dbSNP](https://www.ncbi.nlm.nih.gov/snp/) |
| Promoter hypermethylation | Epigenetic | TAZ silencing in low-grade glioma | [Rao et al., 2018](https://doi.org/10.1038/s41388-018-0449-4) |

Therapeutic Implications

TAZ Modulation for Neurodegeneration

• LATS1/2 inhibitors (TRULI): Prevent TAZ phosphorylation and degradation, restoring nuclear TAZ and neuroprotective gene expression. Shown to promote regeneration in retinal models; brain applications being explored
• MST1/2 inhibitors: XMU-MP-1 inhibits MST1/2, indirectly stabilizing TAZ. Shown to be neuroprotective in stroke models with improved [BBB](/entities/blood-brain-barrier) integrity
• TAZ-mimetic peptides: Engineered TAZ fragments that retain TEAD-binding activity without oncogenic potential are under development
• Statins: HMG-CoA reductase inhibitors activate LATS1/2 and promote TAZ degradation — this may partly explain the conflicting epidemiological data on statin use and dementia risk

TAZ Inhibition for Brain Tumors

• Verteporfin: Disrupts TAZ–TEAD interaction; reduces GBM stem cell viability in vitro but has poor brain penetration
• TEAD palmitoylation inhibitors: VT-104, MYF-01-37 — block TEAD autopalmitoylation required for TAZ–TEAD complex formation
• Genetic approaches: shRNA/ASO-mediated TAZ knockdown reduces GBM xenograft growth

Cell-Type-Specific Targeting

Expression Profile

| Brain Region | Expression Level | Cell Types |
|---|---|---|
| Cerebral cortex (white matter) | High | Oligodendrocytes, astrocytes |
| Hippocampus | Moderate | Astrocytes, OPCs, low in neurons |
| Corpus callosum | High | Oligodendrocytes |
| SVZ/SGZ | Moderate-High | Neural stem cells |
| Spinal cord | Moderate | Astrocytes, oligodendrocytes |
| Substantia nigra | Low-Moderate | Astrocytes, dopaminergic neurons |

See Also

• [YAP1](/genes/yap1) — YAP1, TAZ paralog and Hippo pathway co-effector
• [LATS1](/genes/lats1) — LATS1 kinase, direct upstream regulator of TAZ
• [LATS2](/genes/lats2) — LATS2 kinase, LATS1 paralog
• [MST1](/genes/mst1) — MST1/STK4, upstream Hippo pathway kinase
• [NF2](/genes/nf2) — Merlin, upstream Hippo pathway activator
• [TEAD1](/genes/tead1) — TEAD transcription factor, primary TAZ partner
• [MBP](/genes/mbp) — Myelin basic protein, TAZ transcriptional target
• [Hippo Signaling Pathway](/mechanisms/hippo-signaling-pathway)

External Links

• [NCBI Gene: WWTR1](https://www.ncbi.nlm.nih.gov/gene/25937)
• [UniProt: Q9GZV5](https://www.uniprot.org/uniprot/Q9GZV5)
• [GeneCards: WWTR1](https://www.genecards.org/cgi-bin/carddisp.pl?gene=WWTR1)
• [OMIM: 607392](https://omim.org/entry/607392)
• [Allen Brain Atlas: WWTR1](https://human.brain-map.org/)

References

Pathway Diagram

The following diagram shows the key molecular relationships involving WWTR1 (TAZ) — WW Domain Containing Transcription Regulator 1, Hippo Effector discovered through SciDEX knowledge graph analysis: