HECTD1 Protein

HECTD1 Protein (HECT Domain E3 Ubiquitin Protein Ligase 1)

<div class="infobox infobox-protein">
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<tr><th colspan="2" style="background:#f8e8f8; text-align:center; font-size:1.1em;">HECTD1 Protein</th></tr>
<tr><td><strong>Protein Name</strong></td><td>HECT domain E3 ubiquitin protein ligase 1</td></tr>
<tr><td><strong>Gene</strong></td><td>[HECTD1](/genes/hectd1)</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>[Q9P2M7](https://www.uniprot.org/uniprot/Q9P2M7)</td></tr>
<tr><td><strong>Alternative Names</strong></td><td>HECT domain-containing protein 1, E3 ubiquitin ligase HECTD1</td></tr>
<tr><td><strong>Molecular Weight</strong></td><td>~280 kDa</td></tr>
<tr><td><strong>Subcellular Localization</strong></td><td>Cytoplasm, nucleus, endoplasmic reticulum</td></tr>
<tr><td><strong>Protein Family</strong></td><td>HECT (Homologous to E6AP C-Terminus) E3 ligase family</td></tr>
<tr><td><strong>Enzyme Activity</strong></td><td>E3 ubiquitin-protein ligase</td></tr>
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<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">1 edges</a></td>
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Overview

HECTD1 Protein (HECT Domain E3 Ubiquitin Protein Ligase 1)

<div class="infobox infobox-protein">
<table>
<tr><th colspan="2" style="background:#f8e8f8; text-align:center; font-size:1.1em;">HECTD1 Protein</th></tr>
<tr><td><strong>Protein Name</strong></td><td>HECT domain E3 ubiquitin protein ligase 1</td></tr>
<tr><td><strong>Gene</strong></td><td>[HECTD1](/genes/hectd1)</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>[Q9P2M7](https://www.uniprot.org/uniprot/Q9P2M7)</td></tr>
<tr><td><strong>Alternative Names</strong></td><td>HECT domain-containing protein 1, E3 ubiquitin ligase HECTD1</td></tr>
<tr><td><strong>Molecular Weight</strong></td><td>~280 kDa</td></tr>
<tr><td><strong>Subcellular Localization</strong></td><td>Cytoplasm, nucleus, endoplasmic reticulum</td></tr>
<tr><td><strong>Protein Family</strong></td><td>HECT (Homologous to E6AP C-Terminus) E3 ligase family</td></tr>
<tr><td><strong>Enzyme Activity</strong></td><td>E3 ubiquitin-protein ligase</td></tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">1 edges</a></td>
</tr>
</table>
</div>

Overview

HECTD1 is a member of the HECT (Homologous to E6AP C-Terminus) family of E3 ubiquitin ligases. These enzymes catalyze the transfer of ubiquitin to substrate proteins, targeting them for degradation, modification, or altered cellular localization. HECTD1 has been implicated in [Alzheimer's disease](/diseases/alzheimers-disease), [Parkinson's disease](/diseases/parkinsons-disease), and [Amyotrophic Lateral Sclerosis (ALS)](/diseases/als) through its roles in protein quality control, [autophagy](/entities/autophagy), and cellular stress responses.

Structure and Function

HECT Domain Architecture

HECTD1 contains multiple functional domains:

• N-terminal domain: Contains the substrate recognition region
• Linker region: Connects substrate-binding and catalytic domains
• HECT domain: ~350 amino acid catalytic domain with ubiquitin-binding cysteine
• C-terminal region: Regulatory elements

Ubiquitination Activity

HECTD1 catalyzes ubiquitination through:

Role in Neurodegeneration

Alzheimer's Disease

HECTD1 contributes to AD through protein quality control:

• [Amyloid-beta](/proteins/amyloid-beta) clearance: May ubiquitinate Aβ aggregates for degradation
• [Tau](/proteins/tau) pathology: Involved in tau turnover and clearance
• ER stress: Modulates [unfolded protein response](/entities/unfolded-protein-response)
• Autophagy regulation: Controls selective autophagy pathways

Parkinson's Disease

In PD, HECTD1 functions in:

• Alpha-synuclein turnover: Mediates degradation of [alpha-synuclein](/proteins/alpha-synuclein)
• Mitophagy: Participates in mitochondrial quality control
• Parkin interaction: May cooperate with [parkin](/proteins/parkin) in ubiquitination
• LRRK2 pathways: Interactions with [LRRK2](/proteins/lrrk2) kinase signaling

Amyotrophic Lateral Sclerosis

In ALS, HECTD1 is involved in:

• [TDP-43](/mechanisms/tdp-43-proteinopathy) metabolism: Regulates TDP-43 ubiquitination and clearance
• Protein aggregate clearance: Autophagy of aggregation-prone proteins
• Stress granule dynamics: Modulates stress granule assembly
• Motor neuron survival: Loss of function contributes to degeneration

Molecular Mechanisms

HECTD1 contributes to neurodegeneration through:

Therapeutic Potential

E3 Ligase Modulation

HECTD1 is a potential therapeutic target:

• Activators: Compounds that enhance HECTD1 activity could boost protein clearance
• Inhibitors: Blocking pathological ubiquitination
• Substrate-specific modulators: Targeting specific HECTD1 substrates

Challenges

Key challenges in targeting HECTD1:

• Specificity: Achieving selective modulation
• [Blood-brain barrier](/entities/blood-brain-barrier): CNS drug delivery
• Complexity: Understanding substrate diversity

Clinical Relevance

Genetic Associations

HECTD1 variants are associated with:

• Neurodegenerative disease risk: Some GWAS signals
• Developmental disorders: Mutations cause autism spectrum disorders
• Cancer: Altered expression in various cancers

Biomarker Potential

HECTD1 may serve as:

• Disease marker: Expression levels in patient samples
• Therapeutic target: Modulating protein clearance

See Also

• Ubiquitin-Proteasome System in Neurodegeneration
• Protein Quality Control in Neurodegeneration
• [Autophagy in Neurodegeneration](/mechanisms/autophagy-neurodegeneration) ER Stress in Neurodegeneration

References