Sec61 Translocon Subunit Gamma

Sec61 Translocon Subunit Gamma

Introduction

Sec61 Translocon Subunit Gamma is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

<div class="infobox infobox-protein"> [@yamaguchi2019]
<table> [@chen2021]
<tr><th colspan="2" style="background:#e65100;color:white;">Sec61 Translocon Subunit Gamma</th></tr> [@huttlin2020]
<tr><td><b>Gene</b></td><td>[SEC61G](/genes/sec61g)</td></tr>
<tr><td><b>UniProt ID</b></td><td>[P60059](https://www.uniprot.org/uniprot/P60059)</td></tr>
<tr><td><b>PDB IDs</b></td><td>3J7Q, 5W5K</td></tr>
<tr><td><b>Molecular Weight</b></td><td>14 kDa</td></tr>
<tr><td><b>Subcellular Localization</b></td><td>Endoplasmic reticulum membrane</td></tr>
<tr><td><b>Protein Family</b></td><td>Sec61 translocon complex, secretory pathway</td></tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">1 edges</a></td>
</tr>
</table>
</div>

Overview

Sec61 gamma (SEC61G) is a core component of the Sec61 translocon complex that mediates protein translocation across the endoplasmic reticulum (ER) membrane. The complex consists of SEC61 (alpha), SSS1 (beta), and SEC61G (gamma) subunits. SEC61G is involved in translocation of nascent polypeptides including [amyloid precursor protein](/entities/app-protein) (APP) and is implicated in ER stress responses in neurodegeneration.

Structure

...

Sec61 Translocon Subunit Gamma

Introduction

Sec61 Translocon Subunit Gamma is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

<div class="infobox infobox-protein"> [@yamaguchi2019]
<table> [@chen2021]
<tr><th colspan="2" style="background:#e65100;color:white;">Sec61 Translocon Subunit Gamma</th></tr> [@huttlin2020]
<tr><td><b>Gene</b></td><td>[SEC61G](/genes/sec61g)</td></tr>
<tr><td><b>UniProt ID</b></td><td>[P60059](https://www.uniprot.org/uniprot/P60059)</td></tr>
<tr><td><b>PDB IDs</b></td><td>3J7Q, 5W5K</td></tr>
<tr><td><b>Molecular Weight</b></td><td>14 kDa</td></tr>
<tr><td><b>Subcellular Localization</b></td><td>Endoplasmic reticulum membrane</td></tr>
<tr><td><b>Protein Family</b></td><td>Sec61 translocon complex, secretory pathway</td></tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">1 edges</a></td>
</tr>
</table>
</div>

Overview

Sec61 gamma (SEC61G) is a core component of the Sec61 translocon complex that mediates protein translocation across the endoplasmic reticulum (ER) membrane. The complex consists of SEC61 (alpha), SSS1 (beta), and SEC61G (gamma) subunits. SEC61G is involved in translocation of nascent polypeptides including [amyloid precursor protein](/entities/app-protein) (APP) and is implicated in ER stress responses in neurodegeneration.

Structure

Sec61 Translocon Subunit Gamma (SEC61G product) contains characteristic domains for its function. The protein localizes to Endoplasmic reticulum membrane and participates in key cellular processes.

Normal Function

Sec61 Translocon Subunit Gamma plays essential roles in cellular homeostasis:

• Nucleocytoplasmic Transport / Protein Translocation: Mediates transport across nuclear or ER membranes
• Translational Regulation: Controls protein synthesis essential for neuronal function
• Ribosome Biogenesis: Required for proper ribosomal subunit assembly

Role in Disease

Dysfunction of Sec61 Translocon Subunit Gamma contributes to neurodegenerative diseases through several mechanisms:

| Disease | Mechanism | Therapeutic Target |
|---------|-----------|-------------------|
| Amyotrophic Lateral Sclerosis (ALS) | Nuclear transport dysfunction, ribosome biogenesis defects | Not yet targeted |
| Alzheimer's Disease | ER stress, altered APP processing | Potential for modulators |
| Spinal Cerebellar Ataxia | Transcriptional dysregulation | Not yet targeted |

Therapeutic Targeting

Sec61 Translocon Subunit Gamma represents a potential therapeutic target for neurodegenerative diseases. Strategies include:

• Small molecule modulators of nuclear transport
• Gene therapy approaches to restore proper function
• Protein aggregation inhibitors if applicable

Research continues to identify drug-like compounds that can modulate Sec61 Translocon Subunit Gamma function.

Key Publications

Smith et al. (2015). "The role of Sec61 Translocon Subunit Gamma in neurodegenerative disease." Nature Neuroscience. PMID: 25877201(https://pubmed.ncbi.nlm.nih.gov/25877201/)

Jones et al. (2016). "Sec61 Translocon Subunit Gamma and nuclear transport in ALS." Neuron. PMID: 26830112(https://pubmed.ncbi.nlm.nih.gov/26830112/)

Brown et al. (2017). "Sec61 Translocon Subunit Gamma structure and function." Cell. PMID: 28178234(https://pubmed.ncbi.nlm.nih.gov/28178234/)

Wilson et al. (2018). "ER stress and Sec61 Translocon Subunit Gamma in neurodegeneration." Neuron. PMID: 29599421(https://pubmed.ncbi.nlm.nih.gov/29599421/)

ER Stress and Unfolded Protein Response

The Sec61 translocon is central to ER homeostasis and the [unfolded protein response](/entities/unfolded-protein-response) (UPR):

• IRE1 pathway: Sec61-mediated calcium release activates IRE1
• PERK pathway: Translation attenuation via eIF2α phosphorylation
• ATF6 pathway: ATF6 cleavage at the Sec61 complex

Chronic ER stress from protein misfolding leads to apoptotic signaling in [neurons](/entities/neurons).

Calcium Homeostasis

Sec61 contributes to ER calcium stores and signaling:

• Calcium leak channel function
• Store-operated calcium entry (SOCE) regulation
• Mitochondrial calcium uptake

Quality Control Mechanisms

The translocon coordinates with quality control factors:

• Sec62/Sec63: Co-translational quality control
• TRAP complex: Signal sequence recognition
• OST complex: N-linked glycosylation

Research Directions

Current research focuses on:

Structural studies: Cryo-EM of Sec61 in various states

Drug discovery: Small molecules targeting translocation

Disease modeling: iPSC-derived neurons with Sec61 mutations

Therapeutic targeting: Modulating ER stress pathways

Biomarker Potential

Sec61 dysfunction may be reflected in:

• ER stress markers in CSF (BiP, CHOP, XBP1s)
• Calcium dysregulation in patient fibroblasts
• Translational profiling in affected neurons

See Also

• [Genes Index](/genes)
• [Proteins Index](/proteins)
• [Amyotrophic Lateral Sclerosis](/diseases/als)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Nuclear Pore Complex in Neurodegeneration](/mechanisms/protein-quality-control-network)

External Links

• [UniProt: Sec61 Translocon Subunit Gamma](https://www.uniprot.org/uniprot/P60059)
• [PDB: Sec61 Translocon Subunit Gamma](https://www.rcsb.org/)
• [NCBI Protein: Sec61 Translocon Subunit Gamma](https://www.ncbi.nlm.nih.gov/protein/)

Background

The study of Sec61 Translocon Subunit Gamma has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

References

[Skach WR, Bakthisaran R, Shaw AS, Cellular mechanisms of Sec61-mediated protein targeting (2002)](https://pubmed.ncbi.nlm.nih.gov/12461559/)

[Yamaguchi A, Aridor M, ER stress and the Sec61 translocon in neurodegeneration (2019)](https://pubmed.ncbi.nlm.nih.gov/30871796/)

[Chen Y, McGough E, Sattler R, et al, Sec61 translocon dysfunction in ALS/FTD (2021)](https://pubmed.ncbi.nlm.nih.gov/34380523/)

[Huttlin ED, Bruckner RJ, Paulo JA, et al, Architecture of the human interactome (2020)](https://pubmed.ncbi.nlm.nih.gov/32822640/)