Tuberin Protein

TSC2 Protein (Tuberin)

<div class="infobox infobox-protein">
<table>
<tr><th colspan="2" style="background:#e8f4ea;">TSC2</th></tr>
<tr><td><b>Gene</b></td><td>[TSC2](/genes/tsc2)</td></tr>
<tr><td><b>UniProt ID</b></td><td>[P49816](https://www.uniprot.org/uniprot/P49816)</td></tr>
<tr><td><b>Molecular Weight</b></td><td>198 kDa</td></tr>
<tr><td><b>Subcellular Localization</b></td><td>Cytoplasm, lysosomal membrane</td></tr>
<tr><td><b>Protein Family</b></td><td>TSC family, GAP domain proteins</td></tr>
<tr><td><b>Disease</b></td><td>Tuberous sclerosis complex</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/atherosclerosis" style="color:#ef9a9a">Atherosclerosis</a>, <a href="/wiki/autism" style="color:#ef9a9a">Autism</a>, <a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a>, <a href="/wiki/carcinoma" style="color:#ef9a9a">Carcinoma</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">226 edges</a></td>
</tr>
</table>
</div>

Overview

TSC2 (Tuberin) is a tumor suppressor protein that forms a heterodimeric complex with TSC1 (hamartin) to regulate mTORC1 signaling. The [TSC2](/genes/tsc2) gene encodes a 198 kDa protein with multiple functional domains. TSC2 mutations cause tuberous sclerosis complex (TSC), a genetic disorder characterized by benign tumors throughout the body, including the brain.

Structure

TSC2 contains several functionally important domains:

TSC2 Protein (Tuberin)

<div class="infobox infobox-protein">
<table>
<tr><th colspan="2" style="background:#e8f4ea;">TSC2</th></tr>
<tr><td><b>Gene</b></td><td>[TSC2](/genes/tsc2)</td></tr>
<tr><td><b>UniProt ID</b></td><td>[P49816](https://www.uniprot.org/uniprot/P49816)</td></tr>
<tr><td><b>Molecular Weight</b></td><td>198 kDa</td></tr>
<tr><td><b>Subcellular Localization</b></td><td>Cytoplasm, lysosomal membrane</td></tr>
<tr><td><b>Protein Family</b></td><td>TSC family, GAP domain proteins</td></tr>
<tr><td><b>Disease</b></td><td>Tuberous sclerosis complex</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/atherosclerosis" style="color:#ef9a9a">Atherosclerosis</a>, <a href="/wiki/autism" style="color:#ef9a9a">Autism</a>, <a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a>, <a href="/wiki/carcinoma" style="color:#ef9a9a">Carcinoma</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">226 edges</a></td>
</tr>
</table>
</div>

Overview

TSC2 (Tuberin) is a tumor suppressor protein that forms a heterodimeric complex with TSC1 (hamartin) to regulate mTORC1 signaling. The [TSC2](/genes/tsc2) gene encodes a 198 kDa protein with multiple functional domains. TSC2 mutations cause tuberous sclerosis complex (TSC), a genetic disorder characterized by benign tumors throughout the body, including the brain.

Structure

TSC2 contains several functionally important domains:

• N-terminal domain: TSC1-binding region
• GAP domain (Rhodanese homology domain): GTPase-activating protein function
• Transactivation domain: C-terminal region for transcriptional regulation
• Multiple phosphorylation sites: For regulation by kinases including AKT, AMPK, and GSK3β

Biological Function

TSC1/TSC2 Complex

The TSC1-TSC2 complex functions as a tumor suppressor by regulating mTORC1:

| Function | Mechanism |
|----------|-----------|
| GAP activity | TSC2 activates GTP hydrolysis on Rheb, inhibiting mTORC1 |
| Complex stability | TSC1 stabilizes TSC2 and facilitates its localization |
| Lysosomal recruitment | Complex localizes to lysosomes for Rheb regulation |

mTORC1 Regulation

The TSC complex is a critical regulator of cellular growth:

• Growth factor signaling: PI3K/AKT phosphorylates and inhibits TSC2
• Energy sensing: AMPK activates TSC2 during energy stress
• Nutrient sensing: Amino acids activate mTORC1 independently of TSC

Downstream Effects

mTORC1 regulates:

• Protein synthesis via S6K and 4E-BP1
• [Autophagy](/entities/autophagy) inhibition
• Lipid synthesis
• Mitochondrial metabolism

Role in Neurodegeneration

Alzheimer's Disease

TSC2 dysfunction may contribute to AD pathogenesis:

Parkinson's Disease

• Autophagy impairment: TSC2/mTOR affects [alpha-synuclein](/proteins/alpha-synuclein) clearance
• Lysosomal function: TSC2 regulates lysosomal biogenesis
• Mitochondrial health: mTORC1 modulates mitochondrial dynamics

Therapeutic Potential

mTOR inhibitors (rapamycin, everolimus) show promise:

• Enhanced autophagy
• Reduced protein aggregation
• Improved cognitive function in models

See Also

• [TSC2 Gene](/genes/tsc2)

External Links

• [GeneCards: TSC2](https://www.genecards.org/cgi-bin/carddisp.pl?gene=TSC2)

TSC and Neurological Features

Tuberous sclerosis complex includes:

• Epilepsy: Cortical tubers cause seizures
• Intellectual disability: Variable severity
• Autism spectrum disorders: Common comorbidity
• Brain tumors: Subependymal giant cell astrocytomas (SEGAs)

Therapeutic Approaches

mTOR inhibitors for TSC:

• Everolimus: FDA-approved for SEGA and renal angiomyolipoma
• Sirolimus: Rapamycin for various TSC manifestations
• Topical formulations: For skin lesions

Research Models

• Knockout mice: Tsc2 deletion recapitulates disease
• Organoids: Patient-derived brain organoids
• iPSC models: Neurons from TSC patients

Regulation of mTORC1

Key regulatory mechanisms:

• Growth factors: Insulin, IGF-1 activate PI3K/AKT
• Energy status: AMPK senses low ATP
• Oxygen levels: Hypoxia induces TSC expression
• Amino acids: Rag GTPases bypass TSC

Interaction Partners

Key TSC2-interacting proteins:

• TSC1: Stabilizing partner
• Rheb: GAP substrate
• AMPK: Energy sensing
• AKT/PKB: Growth factor signaling
• GSK3beta: Wnt pathway cross-talk

References