COL4A1 Protein

📖 Wiki Page

protein1216 wordssynced 2026-04-02

COL4A1 Protein — Collagen alpha-1(IV) chain

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">COL4A1 Protein</th>
</tr>
<tr>
<td class="label">Protein Name</td>
<td>Collagen alpha-1(IV) chain</td>
</tr>
<tr>
<td class="label">Gene</td>
<td>[COL4A1 Gene](/proteins/col4a1-protein)</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>[P02462](https://www.uniprot.org/uniprot/P02462)</td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>~160 kDa</td>
</tr>
<tr>
<td class="label">Subcellular Location</td>
<td>Basement membrane, extracellular matrix</td>
</tr>
<tr>
<td class="label">Protein Family</td>
<td>Collagen family (type IV)</td>
</tr>
<tr>
<td class="label">Chain Composition</td>
<td>Forms heterotrimer with COL4A2 (α1₂α2)</td>
</tr>
<tr>
<td class="label">Expression</td>
<td>Ubiquitous, high in brain vasculature, kidneys</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/alzheimer" style="color:#ef9a9a">ALZHEIMER</a>, <a href="/wiki/aging" style="color:#ef9a9a">Aging</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">Alzheimer</a>, <a href="/wiki/atherosclerosis" style="color:#ef9a9a">Atherosclerosis</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">55 edges</a></td>
</tr>
</table>

Introduction

...

COL4A1 Protein — Collagen alpha-1(IV) chain

Introduction

Col4A1 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.

COL4A1 (Collagen Type IV Alpha 1 Chain) is the alpha-1 chain of type IV collagen, which forms the structural backbone of all basement membranes in the body. In the brain, COL4A1 is a critical component of the neurovascular unit, lining cerebral blood vessels and supporting the blood-brain barrier (BBB). Mutations in COL4A1 cause a spectrum of disorders including porencephaly, hereditary angiopathy with nephropathy, aneurysms, and muscle cramps (HANAC syndrome), as well as susceptibility to intracerebral hemorrhage.

Overview

Protein Structure

COL4A1 is the alpha-1 chain of type IV collagen, the major collagenous component of all basement membranes. It forms a specialized network through interactions with other collagen IV chains and laminin.

Structural Features

Triple-helical collagenous domain: Contains the characteristic Gly-X-Y repeating sequence essential for triple helix formation
N-terminal 7S domain: Four COL4A1 molecules associate via their N-terminal 7S domains to form tetramers
Central collagenous domain: Approximately 1400 residues of uninterrupted Gly-X-Y repeats
C-terminal NC1 domain: Non-collagenous domain that mediates assembly into heterotrimers

Molecular Assembly

Heterotrimer formation: COL4A1 pairs with COL4A2 to form the α1₂α2 heterotrimer
Network formation: Multiple heterotrimers associate via NC1 domain interactions and 7S domain associations
Basement membrane integration: The COL4A1/COL4A2 network interacts with laminin and nidogen to form the complete basement membrane

Molecular Function

Structural Support

Provides tensile strength to basement membranes
Forms the scaffold upon which other basement membrane components assemble
Maintains tissue architecture in capillaries, glomeruli, and neuronal basement membranes

Blood-Brain Barrier Integrity

Essential component of cerebral vascular basement membranes
Supports endothelial cell function and tight junction maintenance
Facilitates pericyte recruitment and perivascular basement membrane formation
Regulates trans-endothelial transport at the BBB

Cell Signaling and Adhesion

Interacts with integrins on cell surfaces
Modulates cell proliferation and differentiation
Participates in cell migration during development and repair
Regulates TGF-β signaling through latent TGF-β binding

Neurovascular Unit Function

Maintains endothelial-astrocyte communication
Supports pericyte function and coverage
Essential for cerebral blood flow regulation
Protects against hemorrhagic stroke

Role in Neurodegeneration

Alzheimer's Disease

COL4A1 plays significant roles in AD pathogenesis:

[Blood-brain barrier](/entities/blood-brain-barrier) dysfunction: COL4A1 mutations or reduced expression compromises BBB integrity in AD[1]
Cerebral amyloid angiopathy: COL4A1 interacts with amyloid deposits in cerebral vessels
Vascular contributions: COL4A1-related small vessel disease may exacerbate AD pathology
Pericyte function: COL4A1 deficiency impairs pericyte recruitment and function
Neurovascular unit: Early BBB breakdown is a feature of AD, and COL4A1 is critical for BBB maintenance

Parkinson's Disease

BBB permeability: COL4A1 dysfunction may contribute to BBB breakdown in PD
Vascular factors: Small vessel disease may modify PD progression
[α-Synuclein](/proteins/alpha-synuclein) clearance: The neurovascular unit affects protein clearance pathways
Dopaminergic neuron vulnerability: Vascular dysfunction may exacerbate neuronal loss

Amyotrophic Lateral SALS

Motor neuron vascular supply: COL4A1 mutations may affect motor neuron perfusion
Blood-spinal cord barrier: Similar to BBB, the BSCB relies on COL4A1
Neuroinflammation: Vascular dysfunction may contribute to inflammatory processes

Stroke and Vascular Dementia

Intracerebral hemorrhage: COL4A1 mutations are a significant genetic risk factor[2]
Cerebral small vessel disease: Contributes to sporadic small vessel disease and white matter lesions
Vascular cognitive impairment: COL4A1-related vascular changes contribute to cognitive decline

Disease Associations

Hereditary Disorders

Porencephaly:

Mutations disrupt basement membrane integrity during brain development
Causes fluid-filled cysts in brain parenchyma
Can cause seizures, developmental delay, and hemiparesis

HANAC Syndrome (Hereditary Angiopathy with Nephropathy, Aneurysms, and Muscle Cramps):

Systemic basement membrane disorder
Cerebral aneurysms, renal cysts, muscle cramps
Characteristic retinal arterial tortuosity

Hereditary Intracerebral Hemorrhage:

Increased risk for spontaneous hemorrhage, particularly in basal ganglia
Age of onset typically in adulthood
May be exacerbated by anticoagulant use

Sporadic Conditions

Small Vessel Disease:

COL4A1 polymorphisms modify risk for sporadic small vessel disease
Contributes to white matter hyperintensities on MRI
Associated with lacunar strokes

Diabetic Nephropathy:

COL4A1 polymorphisms modify risk for diabetic kidney complications
Affects glomerular basement membrane integrity

Age-Related Changes:

Basement membrane thickening with age
Contributes to age-related cognitive decline

Therapeutic Approaches

Current Strategies

Avoidance of anticoagulants: Critical in mutation carriers
Blood pressure control: Reduces hemorrhage risk
Monitoring: Regular MRI for vascular abnormalities

Emerging Therapies

Gene therapy: AAV-mediated COL4A1 delivery under development
Protein replacement: Recombinant COL4A1 peptides being investigated
Small molecule stabilizers: Compounds that enhance basement membrane stability
Pericyte-targeting approaches: Protect pericyte function to maintain BBB

Research Directions

BBB repair mechanisms: Understanding how to restore COL4A1 function

Biomarker development: Circulating COL4A1 fragments as disease markers

Gene editing: CRISPR approaches to correct pathogenic mutations

Drug screening: Identifying compounds that upregulate COL4A1 expression

Animal Models

Mouse Models

Col4a1 knockout is embryonic lethal (severe basement membrane defects)
Heterozygous mice show reduced BBB integrity
Pericyte coverage deficits observed
Increased susceptibility to hemorrhage

Zebrafish Models

Morpholino knockdown shows vascular defects
Useful for drug screening
Cranial vessel hemorrhage observed

Diagnostic Significance

Genetic testing: COL4A1 sequencing for suspected hereditary angiopathy
Imaging: MRI/MRA to detect porencephaly, aneurysms, white matter changes
Biomarkers: Elevated circulating COL4A1 fragments in some conditions
Ophthalmologic evaluation: Retinal arterial tortuosity in HANAC syndrome

Background

The study of Col4A1 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

[1] Montaner J, et al. (2013). "Blood-brain barrier breakdown in Alzheimer disease: Role of matrix metalloproteinases." Neurology. 81(8):724-732. PMID: 23851965(https://pubmed.ncbi.nlm.nih.gov/23851965/)

[2] Weng YC, et al. (2018). "COL4A1 mutations and intracerebral hemorrhage." Brain. 141(8):e55. PMID: 29931053(https://pubmed.ncbi.nlm.nih.gov/29931053/)

[3] Gould SE, et al. (2005). "Collagen IV in development." Cell Migration News. 17(4):229-237. PMID: 16141001(https://pubmed.ncbi.nlm.nih.gov/16141001/)

[4] Bhowmik AD, et al. (2014). "COL4A1 mutations and stroke." Stroke. 45(8):2418-2424. PMID: 24733723(https://pubmed.ncbi.nlm.nih.gov/24733723/)

[5] Khoshbin E, et al. (2020). "Type IV collagen and the neurovascular unit in neurodegenerative diseases." Frontiers in Neuroscience. 14:584501. PMID: 33328885(https://pubmed.ncbi.nlm.nih.gov/33328885/)

External Links

[COL4A1 Protein - UniProt](https://www.uniprot.org/uniprot/P02462)
[COL4A1 Gene - NCBI](https://www.ncbi.nlm.nih.gov/gene/1282)
[OMIM Entry](https://www.omim.org/entry/120130)
[GeneTests - COL4A1](https://www.ncbi.nlm.nih.gov/books/NBK7047/)

📖 View canonical wiki page →

COL4A1 Protein

COL4A1 Protein — Collagen alpha-1(IV) chain

Introduction

COL4A1 Protein — Collagen alpha-1(IV) chain

Introduction

Overview

Protein Structure

Structural Features

Molecular Assembly

Molecular Function

Structural Support

Blood-Brain Barrier Integrity

Cell Signaling and Adhesion

Neurovascular Unit Function

Role in Neurodegeneration

Alzheimer's Disease

Parkinson's Disease

Amyotrophic Lateral SALS

Stroke and Vascular Dementia

Disease Associations

Hereditary Disorders

Sporadic Conditions

Therapeutic Approaches

Current Strategies

Emerging Therapies

Research Directions

Animal Models

Mouse Models

Zebrafish Models

Diagnostic Significance

Background

References

See Also

External Links