TUBA4A Protein

TUBA4A Protein

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">TUBA4A — Tubulin Alpha-4A Protein</th>
</tr>
<tr>
<td class="label">Protein Name</td>
<td><strong>Tubulin Alpha-4A</strong></td>
</tr>
<tr>
<td class="label">Gene</td>
<td>[TUBA4A](/genes/tuba4a)</td>
</tr>
<tr>
<td class="label">UniProt</td>
<td><a href="https://www.uniprot.org/uniprot/P68366" target="_blank">P68366</a></td>
</tr>
<tr>
<td class="label">PDB Structures</td>
<td><a href="https://www.ebi.ac.uk/pdbe/search/pdb?query=tu ba4a" target="_blank">5JCF, 6I2D</a></td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>~50 kDa</td>
</tr>
<tr>
<td class="label">Subcellular Localization</td>
<td>Cytoplasm, Axons, Dendrites, Microtubules</td>
</tr>
<tr>
<td class="label">Protein Family</td>
<td>Alpha-tubulin family</td>
</tr>
<tr>
<td class="label">Diseases</td>
<td>[Amyotrophic Lateral Sclerosis](/diseases/als), [Primary Lateral Sclerosis](/diseases/primary-lateral-sclerosis)</td>
</tr>
</table>

TUBA4A Protein — Tubulin Alpha-4A

Introduction

Tuba4A 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.

Overview

...

TUBA4A Protein

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">TUBA4A — Tubulin Alpha-4A Protein</th>
</tr>
<tr>
<td class="label">Protein Name</td>
<td><strong>Tubulin Alpha-4A</strong></td>
</tr>
<tr>
<td class="label">Gene</td>
<td>[TUBA4A](/genes/tuba4a)</td>
</tr>
<tr>
<td class="label">UniProt</td>
<td><a href="https://www.uniprot.org/uniprot/P68366" target="_blank">P68366</a></td>
</tr>
<tr>
<td class="label">PDB Structures</td>
<td><a href="https://www.ebi.ac.uk/pdbe/search/pdb?query=tu ba4a" target="_blank">5JCF, 6I2D</a></td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>~50 kDa</td>
</tr>
<tr>
<td class="label">Subcellular Localization</td>
<td>Cytoplasm, Axons, Dendrites, Microtubules</td>
</tr>
<tr>
<td class="label">Protein Family</td>
<td>Alpha-tubulin family</td>
</tr>
<tr>
<td class="label">Diseases</td>
<td>[Amyotrophic Lateral Sclerosis](/diseases/als), [Primary Lateral Sclerosis](/diseases/primary-lateral-sclerosis)</td>
</tr>
</table>

TUBA4A Protein — Tubulin Alpha-4A

Introduction

Tuba4A 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.

Overview

TUBA4A (Tubulin Alpha-4A) is a member of the alpha tubulin family that forms heterodimers with beta-tubulin to create microtubules, essential cytoskeletal elements in all eukaryotic cells. In [neurons](/entities/neurons), TUBA4A is particularly important for axonal integrity and function["@wu2014"].

Structure

TUBA4A is a 450-amino acid protein with a conserved tubulin fold characteristic of all alpha-tubulins:

• N-terminal domain: GTP-binding site (essential for dimerization)
• Intermediate domain: Taxol-binding site
• C-terminal domain: Motor protein binding and post-translational modification sites

The protein undergoes several post-translational modifications that regulate its function:

• Acetylation: Lys40 acetylation marks stable microtubules
• Tyrosination/detyrosination: Cycling between tyrosinated and glutamylated forms
• Polyglutamylation: Long polyglutamate chains regulate motor protein binding

Normal Function

In neurons, TUBA4A-containing microtubules serve critical functions:

Axonal transport: Provide tracks for kinesin and dynein motors

Axon guidance: Support growth cone dynamics during development

Synaptic maintenance: Enable vesicle cycling at presynaptic terminals

Mitochondrial distribution: Facilitate mitochondrial trafficking and positioning

Cytoskeletal integrity: Maintain neuronal morphology

TUBA4A is highly expressed in motor neurons and cortical neurons, making these cell types particularly vulnerable to TUBA4A mutations[@janke2010].

Role in Disease

Amyotrophic Lateral Sclerosis (ALS)

Pathogenic TUBA4A mutations cause autosomal dominant ALS through several mechanisms:

Loss of microtubule stability: Mutations reduce microtubule polymerization efficiency and increase depolymerization rates. This leads to:

• Impaired axonal transport of survival factors (BDNF, NGF)
• Defective mitochondrial trafficking and energy deficits
• Reduced synaptic vesicle recycling
• Accumulation of protein aggregates

Aggregation propensity: Some TUBA4A mutants show increased tendency to form aggregates that sequester other microtubule proteins.

Therapeutic Targeting

Microtubule-stabilizing approaches are being explored for TUBA4A-related ALS:

| Approach | Example | Status |
|----------|---------|--------|
| Small molecules | EpoD, Taxol derivatives | Preclinical |
| Natural compounds | Epothilone D | Clinical trials |
| Gene therapy | AAV-TUBA4A | Preclinical |

See Also

• [TUBA4A Gene](/proteins/tuba4a-protein)
• [Amyotrophic Lateral Sclerosis](/diseases/als)
• [Motor Neurons](/cell-types/spinal-motor-neurons)
• [Microtubule Dysfunction](/mechanisms/microtubule-dysfunction)
• [Axonal Transport](/mechanisms/axonal-transport)
• [Cytoskeletal Dynamics](/mechanisms/cytoskeletal-dynamics-axonal-transport)

External Links

• [UniProt: TUBA4A](https://www.uniprot.org/uniprot/P68366)
• [PDB: TUBA4A](https://www.ebi.ac.uk/pdbe/search/pdb?query=tuba4a)
• [NCBI Protein: TUBA4A](https://www.ncbi.nlm.nih.gov/protein)

Post-Translational Modifications

TUBA4A undergoes various post-translational modifications that regulate its function:

• Acetylation: At Lys40, affects microtubule stability and dynamics
• Tyrosination/detyrosination: Cycling of terminal tyrosine affects microtubule function
• Polyglutamylation: Modifies microtubule interactions with binding proteins
• Phosphorylation: Affects polymerization and stability

Tubulin Isoforms in the Brain

The brain expresses multiple tubulin isoforms:

| Isoform | Gene | Neuronal Expression | Specific Functions |
|---------|------|---------------------|---------------------|
| TUBA4A | TUBA4A | Ubiquitous | General cytoskeleton |
| TUBA1A | TUBA1A | High in neurons | Axonal transport |
| TUBA1B | TUBA1B | Ubiquitous | Proliferation |
| TUBA3E | TUBA3E | Low in brain | Specialized roles |

Microtubule Dynamics

TUBA4A contributes to microtubule dynamics:

Dynamic Instability

• Growth and shrinkage phases
• Catastrophe and rescue events
• Regulation by microtubule-associated proteins (MAPs)

Transport Function

• Kinesin-mediated anterograde transport
• Dynein-mediated retrograde transport
• Organelle and vesicle trafficking

Therapeutic Targeting

Drug Development

• Microtubule-stabilizing agents: Enhance microtubule function
• Kinesin inhibitors: Target axonal transport deficits
• Dynein modulators: Enhance retrograde transport

Gene Therapy Approaches

• AAV-mediated TUBA4A delivery
• Gene replacement for null mutations
• CRISPR-based correction

Research Methods

• Live-cell imaging: Microtubule dynamics visualization
• cryo-EM: Structure determination
• Mass spectrometry: PTM analysis
• Primary neurons: Functional studies

Background

The study of Tuba4A 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.

References

[Wu CH, Fallini C, Ticozzi N, et al, Mutations in the tubulin alpha-4A subunit gene (TUBA4A) in familial and sporadic amyotrophic lateral sclerosis (2014)](https://pubmed.ncbi.nlm.nih.gov/24462097/)

[Janke C, Kneussel M, Tubulin post-translational modifications: emerging functions in neuronal trafficking (2010)](https://pubmed.ncbi.nlm.nih.gov/20236956/)