eef1a1-protein

eEF1A1 Protein — Eukaryotic Translation Elongation Factor 1 Alpha 1

<div class="infobox infobox-protein">
<table>
<tr><th colspan="2" style="background:#e8f4f8; text-align:center; font-size:1.1em;">eEF1A1 Protein</th></tr>
<tr><td><strong>Protein Name</strong></td><td>Eukaryotic Translation Elongation Factor 1 Alpha 1</td></tr>
<tr><td><strong>Gene</strong></td><td>[EEF1A1](/genes/eef1a1)</td></tr>
<tr><td><strong>UniProt ID</strong></td><td><a href="https://www.uniprot.org/uniprot/P68104" target="_blank">P68104</a></td></tr>
<tr><td><strong>PDB ID</strong></td><td>1IJN, 1QVO, 2J0W, 5T5R</td></tr>
<tr><td><strong>Molecular Weight</strong></td><td>50.1 kDa</td></tr>
<tr><td><strong>Subcellular Localization</strong></td><td>Cytoplasm, Nucleus, Mitochondria</td></tr>
<tr><td><strong>Protein Family</strong></td><td>EF-1 alpha family (GTP-binding proteins)</td></tr>
<tr><td><strong>Enzyme Classification</strong></td><td>GTPase (EF-Tu homolog)</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/ad" style="color:#ef9a9a">AD</a>, <a href="/wiki/ali" style="color:#ef9a9a">ALI</a>, <a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/ami" style="color:#ef9a9a">AMI</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">71 edges</a></td>
</tr>
</table>
</div>

Overview

eEF1A1 Protein — Eukaryotic Translation Elongation Factor 1 Alpha 1

<div class="infobox infobox-protein">
<table>
<tr><th colspan="2" style="background:#e8f4f8; text-align:center; font-size:1.1em;">eEF1A1 Protein</th></tr>
<tr><td><strong>Protein Name</strong></td><td>Eukaryotic Translation Elongation Factor 1 Alpha 1</td></tr>
<tr><td><strong>Gene</strong></td><td>[EEF1A1](/genes/eef1a1)</td></tr>
<tr><td><strong>UniProt ID</strong></td><td><a href="https://www.uniprot.org/uniprot/P68104" target="_blank">P68104</a></td></tr>
<tr><td><strong>PDB ID</strong></td><td>1IJN, 1QVO, 2J0W, 5T5R</td></tr>
<tr><td><strong>Molecular Weight</strong></td><td>50.1 kDa</td></tr>
<tr><td><strong>Subcellular Localization</strong></td><td>Cytoplasm, Nucleus, Mitochondria</td></tr>
<tr><td><strong>Protein Family</strong></td><td>EF-1 alpha family (GTP-binding proteins)</td></tr>
<tr><td><strong>Enzyme Classification</strong></td><td>GTPase (EF-Tu homolog)</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/ad" style="color:#ef9a9a">AD</a>, <a href="/wiki/ali" style="color:#ef9a9a">ALI</a>, <a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/ami" style="color:#ef9a9a">AMI</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">71 edges</a></td>
</tr>
</table>
</div>

Overview

eEF1A1 (Eukaryotic Translation Elongation Factor 1 Alpha 1) is a fundamental component of the protein synthesis machinery, essential for the elongation phase of translation in all eukaryotic cells. As the eukaryotic homolog of bacterial EF-Tu, eEF1A1 delivers aminoacyl-tRNAs to the ribosome in a GTP-dependent manner, making it indispensable for cellular protein production. Beyond this canonical function, eEF1A1 has emerged as a multifunctional protein with critical roles in cytoskeletal organization, cell signaling, [apoptosis](/entities/apoptosis), and stress response pathways—functions that have profound implications for neurodegenerative diseases.

The human eEF1A1 protein is one of the most abundant cellular proteins, comprising approximately 1-3% of total cellular protein content. This reflects its central role in translation, the fundamental process of protein synthesis that underlies all cellular functions. The protein is encoded by the EEF1A1 gene on chromosome 6q14.1 and is ubiquitously expressed in all tissues, with particularly high levels in metabolically active cells including [neurons](/entities/neurons).

A closely related isoform, eEF1A2 (encoded by EEF1A2), shows more restricted tissue distribution—high expression in brain, heart, and muscle, with low or undetectable levels in other tissues. Importantly, eEF1A2 is the predominant isoform in mature neurons, and mutations or dysregulation of this isoform have been directly linked to neurodegenerative conditions including [Alzheimer's disease](/diseases/alzheimers-disease), [Parkinson's disease](/diseases/parkinsons-disease), and [amyotrophic lateral sclerosis](/diseases/als)[@ding2012]. The distinction between these isoforms is clinically significant, as they appear to have partially distinct functions despite their high sequence similarity.

The multifaceted nature of eEF1A1 has made it a focus of intense research in neurodegeneration. Its roles in protein synthesis, specifically at the synapse, are essential for synaptic plasticity and memory formation. Meanwhile, its participation in stress granule formation and the cellular stress response links it to protein aggregation diseases. Understanding eEF1A1 function in these contexts offers potential therapeutic targets for neurodegenerative disorders.

Structure

Primary Structure

The human eEF1A1 protein consists of 462 amino acids with a molecular weight of approximately 50.1 kDa. The protein adopts the characteristic GTP-binding protein fold shared with other translation factors and GTPases:

Domain Organization:

• Domain I (N-terminal, residues 1-200): Contains the GTP-binding pocket and is the most conserved region
• Domain II (middle region, residues 200-330): Forms the interface with the tRNA
• Domain III (C-terminal, residues 330-462): Involved in protein-protein interactions

• GTP-binding motif: Contains the characteristic GxxxxGKST sequence (P-loop)
• Switch regions: Conformational changes between GTP and GDP states
• tRNA-binding interface: Extensive surface for aminoacyl-tRNA interaction

Three-Dimensional Structure

The crystal structures of eEF1A1 have revealed the molecular basis of its function[@bott2006]:

GTP-Bound State:

• Domain I adopts the canonical GTPase fold
• The switch regions are in the active conformation
• tRNA binding site is exposed and accessible

• Significant conformational changes in switch regions
• The tRNA binding site is reduced
• Domain II rotates relative to domain I

• The aminoacyl-tRNA sits in a groove formed by domains I and II
• The CCA end is specifically recognized
• The ester bond between tRNA and amino acid is protected

Isoform Differences

eEF1A1 and eEF1A2 share 92% sequence identity, with the major differences in:

• N-terminal region: Contains targeting signals for specific cellular functions
• Regulatory sequences: Post-translational modification sites differ
• Expression control: Different promoters and regulatory elements

Post-Translational Modifications

eEF1A1 undergoes several important modifications:

• Lysine acetylation: Multiple acetylation sites affect function
• Phosphorylation: Modulates activity and interactions
• Methylation: Arginine methylation affects interactions
• Ubiquitination: Targets for degradation

Normal Function

Canonical Translation Function

The primary function of eEF1A1 is delivering aminoacyl-tRNAs to the ribosome during the elongation phase of protein synthesis[@sanford2004]. This process proceeds through a carefully regulated cycle:

This cycle occurs at a rate of approximately 3-5 amino acids per second and is repeated thousands of times during the synthesis of a typical protein.

Neuronal Functions

In neurons, eEF1A1 has critical functions beyond general translation:

Synaptic Translation

• Synapse-specific mRNAs: eEF1A1 localizes to dendritic spines
• Activity-dependent translation: Synaptic activation regulates eEF1A1 function
• Postsynaptic density: Enriched in the postsynaptic density fraction

Memory Formation

• Translation during LTP: eEF1A1 activity increases during long-term potentiation
• Protein synthesis requirement: Inhibiting translation blocks memory consolidation
• Synaptic protein synthesis: Specific synaptic proteins require eEF1A1-mediated translation

Cytoskeletal Functions

• Actin binding: Binds F-actin, affecting cytoskeletal organization
• Microtubule interactions: Associates with microtubules
• Cell motility: Affects neuronal migration and axon guidance

Non-Canonical Functions

eEF1A1 has acquired diverse non-canonical functions during evolution:

Signal Transduction

• Kinase substrate: Phosphorylated by various kinases
• Scaffold function: Forms complexes with signaling proteins
• Second messenger effects: Involved in cAMP and calcium signaling

Apoptosis Regulation

• Pro-apoptotic function: Can promote apoptosis under certain conditions
• Anti-apoptotic function: In other contexts, protects against cell death
• Mitochondrial pathway: Involved in mitochondrial apoptosis

Stress Response

• Stress granules: eEF1A1 localizes to stress granules[@mateju2017]
• Phase separation: Participates in membraneless organelle formation
• Translation arrest: Contributes to translational shutdown during stress

Role in Neurodegeneration

Alzheimer's Disease

eEF1A1 dysregulation is implicated in [Alzheimer's disease](/diseases/alzheimers-disease) through multiple mechanisms[@gu2011][@hernandez2019]:

Protein Synthesis Dysregulation

• Translational fidelity: Altered accuracy in AD brain
• Synaptic translation: Impaired local protein synthesis at synapses
• Global translation: Reduced translation capacity in affected neurons

Tau Pathology

• Tau interaction: eEF1A1 can bind to tau protein
• Phosphorylation: Tau pathology affects eEF1A1 function
• Aggregation: eEF1A1 may influence tau aggregation

Amyloid-Beta Effects

• Toxicity mediation: eEF1A1 involved in Aβ-induced toxicity
• Synaptic function: Aβ disrupts eEF1A1-mediated translation
• Neuronal vulnerability: eEF1A1 alterations contribute to neuronal death

Parkinson's Disease

In [Parkinson's disease](/diseases/parkinsons-disease)[@liu2016], eEF1A1 plays several roles:

Alpha-Synuclein Interactions

• Aggregation: eEF1A1 may influence α-synuclein aggregation
• Translation regulation: α-synuclein affects translational machinery
• Stress granule formation: Linked to α-synuclein pathology

Dopaminergic Neuron Vulnerability

• Protein synthesis demands: High translational demand in dopaminergic neurons
• Mitochondrial function: eEF1A1 affects mitochondrial protein synthesis
• Cellular stress: Altered stress response in PD

Therapeutic Implications

• Translation modulation: Enhancing translation may be protective
• Stress granule targeting: Modulating stress granule dynamics

Amyotrophic Lateral Sclerosis

eEF1A1 and eEF1A2 are strongly implicated in [ALS](/diseases/als)[@negg2018]:

Mutations and Variants

• EEF1A2 mutations: Associated with ALS and dementia
• Dysfunction: Loss-of-function affects neuronal function
• Animal models: EEF1A2 knockout mice develop neurodegeneration

Stress Granule Biology

• Stress granule formation: eEF1A1 in ALS-related stress granules
• TDP-43 pathology: Interaction with TDP-43 in stress granules
• Translation arrest: Persistent stress granules in ALS

Therapeutic Targeting

• Translation enhancement: Improving translation may be beneficial
• Stress granule modulators: Targeting stress granule dynamics

Other Neurodegenerative Conditions

Huntington's Disease

• Translational dysfunction: Impaired protein synthesis
• Stress response: Altered stress granule formation
• Aggregation: Interaction with mutant huntingtin

Frontotemporal Dementia

• Stress granules: eEF1A1 in FTD-related granules
• Translation: Dysregulated translation
• TDP-43 pathology: Links to TDP-43 proteinopathy

Prion Diseases

• Translation dysregulation: Early changes in prion disease
• Stress response: Altered stress granule biology

Interaction Network

eEF1A1 participates in numerous protein-protein interactions:

Translation Machinery

• eEF1B complex: Guanine nucleotide exchange factor
• Aminoacyl-tRNA synthetases: tRNA charging enzymes
• Ribosomal proteins: Interactions at the ribosome

Signaling Proteins

• Kinases: PKA, PKC, CK2
• Phosphatases: PP1, PP2A
• GTPases: Ras family members

Cytoskeletal Proteins

• Actin: F-actin binding
• Tubulin: Microtubule interactions
• Intermediate filaments: Vimentin, others

Stress Response Proteins

• G3BP1: Stress granule formation
• TIA1: Stress granule component
• PABP1: Poly(A)-binding protein

Therapeutic Targeting

Current Approaches

Translation Modulators

• eEF1A1 enhancers: Compounds that improve translation efficiency
• Translation inhibitors: Targeting dysregulated translation
• Selective modulation: Avoiding global translation inhibition

Stress Granule Targeting

• Granule disassembly: Promoting disassembly of pathological granules
• Granule stabilization: Preventing pathological aggregation
• Modulators: Small molecules affecting stress granule dynamics

Challenges

• Multiple functions: Canonical and non-canonical roles complicate targeting
• Isoform specificity: Distinguishing eEF1A1 from eEF1A2
• Cell type specificity: Targeting specific neurons vs. glia
• Therapeutic window: Balancing efficacy and toxicity

Research Directions

• Gene therapy: Targeting eEF1A expression
• Small molecule modulators: Developing selective compounds
• Combination therapy: Targeting multiple pathways

Research Tools and Resources

Experimental Models

• Knockout mice: Eef1a1 and Eef1a2 knockout studies
• Transgenic mice: Overexpression and mutant models
• Cell cultures: Neuronal cultures for in vitro studies

Chemical Probes

• Translation inhibitors: Cycloheximide, puromycin
• GTP analogs: Non-hydrolyzable GTP analogs
• Modulators: Various small molecule modulators

Resources

• UniProt: P68104 (eEF1A1), P41091 (eEF1A2)
• PDB: Structures available (1IJN, 1QVO, 2J0W)
• Antibodies: Available for various applications

Key Publications

Cross-References

• [EEF1A1 Gene](/genes/eef1a1)
• [EEF1A2 Gene](/genes/eef1a2)
• [Translation Machinery](/mechanisms/translation-machinery)
• [Protein Synthesis](/mechanisms/protein-synthesis)
• [Stress Granules](/mechanisms/stress-granules)
• [Synaptic Plasticity](/mechanisms/synaptic-plasticity)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [ALS](/diseases/als)
• [Tau Protein](/proteins/tau)
• [Alpha-Synuclein](/proteins/alpha-synuclein)
• [TDP-43](/proteins/tardbp-protein)

External Links

• [UniProt: eEF1A1](https://www.uniprot.org/uniprot/P68104)
• [UniProt: eEF1A2](https://www.uniprot.org/uniprot/P41091)
• [PDB: eEF1A1](https://www.rcsb.org/structure/1IJN)
• [NCBI Gene: EEF1A1](https://www.ncbi.nlm.nih.gov/gene/1935)
• [NCBI Gene: EEF1A2](https://www.ncbi.nlm.nih.gov/gene/1937)

References