TTR (Transthyretin) Protein

TTR (Transthyretin) Protein

Overview

Ttr (Transthyretin) Protein plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.

Introduction

Ttr (Transthyretin) 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. [@alzheimers]

<div class="infobox .infobox-protein"> [@nih]
<h3>TTR (Transthyretin) Protein</h3>
<table>
<tr><th>Protein Name</th><td>Transthyretin</td></tr>
<tr><th>Gene</th><td>[TTR](/genes/ttr)</td></tr>
<tr><th>UniProt ID</th><td><a href="https://www.uniprot.org/uniprot/P02766" target="_blank">P02766</a></td></tr>
<tr><th>PDB ID</th><td>1TTA, 1BZE, 4TNP</td></tr>
<tr><th>Molecular Weight</th><td>55.9 kDa (tetramer)</td></tr>
<tr><th>Subcellular Localization</th><td>Secreted, extracellular</td></tr>
<tr><th>Protein Family</th><td>Transthyretin family</td></tr>
</table>
</div>

Structure

Transthyretin (TTR) is a 55.9 kDa homotetrameric protein composed of four identical subunits (14 kDa each). Each monomer contains:

• Seven β-strands forming a β-sandwich fold
• Two α-helices
• A central channel that binds thyroid hormone (T4) and retinol-binding protein

• Tetrameric assembly is essential for function
• Monomers can dissociate and misfold
• Amyloidogenic mutations destabilize the tetramer

Normal Function

TTR (Transthyretin) Protein

Overview

Ttr (Transthyretin) Protein plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.

Introduction

Ttr (Transthyretin) 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. [@alzheimers]

<div class="infobox .infobox-protein"> [@nih]
<h3>TTR (Transthyretin) Protein</h3>
<table>
<tr><th>Protein Name</th><td>Transthyretin</td></tr>
<tr><th>Gene</th><td>[TTR](/genes/ttr)</td></tr>
<tr><th>UniProt ID</th><td><a href="https://www.uniprot.org/uniprot/P02766" target="_blank">P02766</a></td></tr>
<tr><th>PDB ID</th><td>1TTA, 1BZE, 4TNP</td></tr>
<tr><th>Molecular Weight</th><td>55.9 kDa (tetramer)</td></tr>
<tr><th>Subcellular Localization</th><td>Secreted, extracellular</td></tr>
<tr><th>Protein Family</th><td>Transthyretin family</td></tr>
</table>
</div>

Structure

Transthyretin (TTR) is a 55.9 kDa homotetrameric protein composed of four identical subunits (14 kDa each). Each monomer contains:

• Seven β-strands forming a β-sandwich fold
• Two α-helices
• A central channel that binds thyroid hormone (T4) and retinol-binding protein

• Tetrameric assembly is essential for function
• Monomers can dissociate and misfold
• Amyloidogenic mutations destabilize the tetramer

Normal Function

Transthyretin is a homotetrameric transport protein produced primarily in the liver and choroid plexus:

Primary functions:

• Thyroid hormone transport: Carries thyroxine (T4) in plasma and CSF
• Retinol transport: Binds retinol-binding protein (RBP) to deliver vitamin A
• Extracellular protein homeostasis: Acts as a "molecular chaperone"

• Liver (main source in plasma)
• Choroid plexus (main source in CSF)
• Retina
• Peripheral nervous system

Role in Neurodegeneration

Transthyretin Amyloidosis (ATTR)

• Autosomal dominant: Caused by TTR gene mutations
• Mechanisms:
• TTR tetramer dissociation → monomer misfolding → amyloid fibril formation
• Amyloid deposition in various tissues
• Clinical variants:
• Familial amyloid polyneuropathy (FAP): Peripheral neuropathy, autonomic dysfunction
• Familial amyloid cardiomyopathy (FAC): Cardiac amyloidosis
• Leptomeningeal amyloidosis: CNS involvement

Wild-type TTR Amyloidosis (Senile Systemic Amyloidosis)

• Age-related: Wild-type TTR forms amyloid with age
• Predominantly cardiac: Deposits in heart
• Carpal tunnel syndrome: Often an early manifestation
• Spinal stenosis: TTR deposits in ligaments

Alzheimer's Disease

• TTR may bind [Aβ](/proteins/amyloid-beta) and modulate its aggregation
• TTR expression is altered in AD
• May have protective role against Aβ toxicity

Parkinson's Disease

• TTR can form amyloid inclusions in some PD cases
• Role in Lewy body pathology is unclear

Therapeutic Targeting

Tetramer Stabilizers (FDA Approved)

• Tafamidis (Vyndaqel): TTR stabilizer, approved for FAP
• Diflunisal: NSAID that stabilizes TTR
• Nitisinone: Reduces TTR production

Gene Silencing (FDA Approved)

• Patisiran (Onpattro): siRNA targeting TTR
• Vutrisiran (Amvuttra): siRNA (subcutaneous)
• Inotersen (Tegsedi): Antisense oligonucleotide

Gene Editing

• CRISPR-based approaches in development

Key Publications

Overview

Ttr (Transthyretin) Protein plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.

Background

The study of Ttr (Transthyretin) 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.

See Also

• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Amyloid Hypothesis](/mechanisms/amyloid-hypothesis)
• [Tau Pathology](/mechanisms/tau-pathology)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Alpha-Synuclein](/mechanisms/alpha-synuclein)

External Links

• [PubMed](https://pubmed.ncbi.nlm.nih.gov/) - Biomedical literature
• [Alzheimer's Disease Neuroimaging Initiative](https://adni.loni.usc.edu/) - Research data
• [Allen Brain Atlas](https://brain-map.org/) - Brain gene expression data

Cross-references

• Gene: [TTR](genes/ttr)
• Diseases: [Transthyretin Amyloidosis|Transthyretin Amyloidosis], [Alzheimer's Disease](diseases/alzheimers), [Parkinson's Disease](diseases/parkinsons)
• Pathways: [Amyloid Fibril Formation](Amyloid Cascade|Amyloid Fibril Formation], [Protein Misfolding|Protein Misfolding]

References