eIF2B3 Protein
Introduction
Eif2B3 Protein 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"> [@eifb2018]
<table> [@vwm2019]
<tr><th>Protein Name</th><td>eIF2B3 (Eukaryotic Translation Initiation Factor 2B Subunit Gamma)</td></tr> [@isrib2018]
<tr><th>Gene</th><td>[EIF2B3](/genes/eif2b3)</td></tr> [@therapeutic2021]
<tr><th>UniProt ID</th><td><a href="https://www.uniprot.org/uniprot/Q9UII2" target="_blank">Q9UII2</a></td></tr> [@glial2018]
<tr><th>PDB Structure</th><td>6O9Y, 6O9Z</td></tr>
<tr><th>Molecular Weight</th><td>50 kDa</td></tr>
<tr><th>Subcellular Localization</th><td>Cytoplasm</td></tr>
<tr><th>Protein Family</th><td>eIF2B family</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/parkinson-disease" style="color:#ef9a9a">Parkinson disease</a>, <a href="/wiki/vanishing-white-matter-disease" style="color:#ef9a9a">vanishing white matter disease</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">6 edges</a></td>
</tr>
</table>
</div>
Overview
Structure
...eIF2B3 Protein
Introduction
Eif2B3 Protein 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"> [@eifb2018]
<table> [@vwm2019]
<tr><th>Protein Name</th><td>eIF2B3 (Eukaryotic Translation Initiation Factor 2B Subunit Gamma)</td></tr> [@isrib2018]
<tr><th>Gene</th><td>[EIF2B3](/genes/eif2b3)</td></tr> [@therapeutic2021]
<tr><th>UniProt ID</th><td><a href="https://www.uniprot.org/uniprot/Q9UII2" target="_blank">Q9UII2</a></td></tr> [@glial2018]
<tr><th>PDB Structure</th><td>6O9Y, 6O9Z</td></tr>
<tr><th>Molecular Weight</th><td>50 kDa</td></tr>
<tr><th>Subcellular Localization</th><td>Cytoplasm</td></tr>
<tr><th>Protein Family</th><td>eIF2B family</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/parkinson-disease" style="color:#ef9a9a">Parkinson disease</a>, <a href="/wiki/vanishing-white-matter-disease" style="color:#ef9a9a">vanishing white matter disease</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">6 edges</a></td>
</tr>
</table>
</div>
Overview
Structure
eIF2B3 is the gamma subunit of the eukaryotic translation initiation factor 2B complex. The eIF2B heterodecamer consists of two copies each of five subunits (alpha, beta, gamma, delta, epsilon), forming a symmetrical complex. The gamma subunit is one of the core structural components that contributes to the stability and organization of the complex[@structure2015].
The eIF2B complex serves as the guanine nucleotide exchange factor (GEF) for eIF2, catalyzing the exchange of GDP for GTP to regenerate active eIF2-GTP. This reaction is essential for translation initiation as the eIF2-GTP-Met-tRNAi ternary complex is required for start codon recognition at the ribosome[@eifb2018].
Normal Function
In the normal nervous system, eIF2B3 plays a critical role in regulating protein synthesis. The eIF2B complex is a central regulator of the integrated stress response (ISR), where cellular stress leads to phosphorylation of eIF2alpha, which allosterically inhibits eIF2B activity. This leads to reduced global translation while selectively promoting the translation of stress-response genes such as ATF4 and CHOP[@vwm2019].
In oligodendrocytes and [astrocytes](/entities/astrocytes), eIF2B function is essential for maintaining white matter integrity. The stress-responsive regulation through eIF2B allows glial cells to adapt to metabolic demands and respond to cellular stress.
Role in Disease
Vanishing White Matter Disease (VWM)
Mutations in EIF2B3 cause vanishing white matter disease, an autosomal recessive leukodystrophy characterized by progressive cerebellar ataxia, spasticity, and white matter degeneration. Pathogenic variants reduce eIF2B activity, impairing the integrated stress response in glial cells. This makes oligodendrocytes and astrocytes vulnerable to various cellular stresses, leading to myelin loss and cystic degeneration of white matter[@isrib2018].
The disease typically presents in early childhood with episodic deterioration triggered by minor infections or trauma. Neuropathologically, VWM shows diffuse rarefaction and cystic degeneration of cerebral white matter.
Therapeutic Targeting
Current therapeutic approaches for VWM focus on enhancing eIF2B activity:
ISRIB (Integrated Stress Response Inhibitor): A small molecule that stabilizes eIF2B and restores its activity despite eIF2alpha phosphorylation. ISRIB has shown promise in preclinical models of VWM[@therapeutic2021].
Guanabenz: An alpha-2 adrenergic agonist that was found to enhance eIF2B function and has been tested in VWM models.
Gene therapy: Approaches to deliver wild-type EIF2B3 to affected tissues are under investigation.Key Publications
[Structure of the eIF2B decameric GEF complex (2015)](https://doi.org/10.1038/nature14888)
[eIF2B and mechanism of translational control (2018)](https://doi.org/10.1016/j.tibs.2018.04.004)
[VWM disease: pathophysiology and therapy (2019)](https://doi.org/10.1016/j.neuropharm.2019.107783)
[ISRIB rescues eIF2B activity in VWM models (2018)](https://pubmed.ncbi.nlm.nih.gov/29429891/)
[Therapeutic targeting of eIF2B in leukodystrophy (2021)](https://doi.org/10.1016/j.pharmthera.2021.107856)
[Glial eIF2B deficiency in VWM pathogenesis (2018)](https://pubmed.ncbi.nlm.nih.gov/29581268/)Background
The study of Eif2B3 Protein 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.
Cross-References
- [EIF2B3 Gene](/genes/eif2b3)
- [eIF2B Complex](/proteins/eif2b-complex)
- [Integrated Stress Response](/mechanisms/integrated-stress-response)
- [Vanishing White Matter Disease](/diseases/vanishing-white-matter-disease)
- [ER Stress Pathway](/mechanisms/er-stress-pathway)
See Also
- [Genes Index](/genes)
- [Proteins Index](/proteins)
- [Translation Initiation Factors](/proteins)
- [eIF2B Complex](/proteins/eif2b-complex)
- [Integrated Stress Response](/mechanisms/integrated-stress-response)
- [ER Stress Pathway](/mechanisms/er-stress-pathway)
External Links
- [UniProt: eIF2B subunits](https://www.uniprot.org/) - Protein database
- [PDB: eIF2B structure](https://www.rcsb.org/) - Structural data
- [Allen Brain Atlas](https://portal.brain-map.org/) - Expression data
References
[Unknown, Structure of the eIF2B decameric GEF complex (2015) (2015)](https://doi.org/10.1038/nature14888)
[Unknown, eIF2B and mechanism of translational control (2018) (2018)](https://doi.org/10.1016/j.tibs.2018.04.004)
[Unknown, VWM disease: pathophysiology and therapy (2019) (2019)](https://doi.org/10.1016/j.neuropharm.2019.107783)
[Unknown, ISRIB rescues eIF2B activity in VWM models (2018) (2018)](https://pubmed.ncbi.nlm.nih.gov/29429891/)
[Unknown, Therapeutic targeting of eIF2B in leukodystrophy (2021) (2021)](https://doi.org/10.1016/j.pharmthera.2021.107856)
[Unknown, Glial eIF2B deficiency in VWM pathogenesis (2018) (2018)](https://pubmed.ncbi.nlm.nih.gov/29581268/)