LRP6 Protein
Introduction
<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">LRP6 Protein</th>
</tr>
<tr>
<td class="label">Domain</td>
<td>Position</td>
</tr>
<tr>
<td class="label">Signal peptide</td>
<td>1-23 aa</td>
</tr>
<tr>
<td class="label">LDLR repeats 1-3</td>
<td>24-600 aa</td>
</tr>
<tr>
<td class="label">LDLR repeats 4-6</td>
<td>600-900 aa</td>
</tr>
<tr>
<td class="label">EGF-like domains</td>
<td>900-1200 aa</td>
</tr>
<tr>
<td class="label">Transmembrane</td>
<td>1380-1402 aa</td>
</tr>
<tr>
<td class="label">Cytoplasmic tail</td>
<td>1403-1613 aa</td>
</tr>
<tr>
<td class="label">Modification</td>
<td>Site</td>
</tr>
<tr>
<td class="label">Phosphorylation</td>
<td>S1490, T1479</td>
</tr>
<tr>
<td class="label">Glycosylation</td>
<td>Multiple</td>
</tr>
<tr>
<td class="label">Palmitoylation</td>
<td>C1351</td>
</tr>
<tr>
<td class="label">Ubiquitination</td>
<td>Multiple</td>
</tr>
<tr>
<td class="label">Partner</td>
<td>Interaction Domain</td>
</tr>
<tr>
<td class="label">Wnt proteins</td>
<td>LDLR repeats</td>
</tr>
<tr>
<td class="label">FZD receptors</td>
<td>Extracellular</td>
</tr>
<tr>
<td class="label">DVL</td>
<td>Cytoplasmic</td>
</tr>
<tr>
<td class="label">AXIN</td>
<td>Cytoplasmic</td>
</tr>
<tr>
<td class="label">GSK3β</td>
<td>Cytoplasmic</td>
</tr>
<tr>
<td class="label">Region</td>
<td>Expression Level</td>
</tr>
<tr>
<td class="label">[Hippocampus](/brain-regions/hippocampus)</td>
<td>Very high</td>
</tr>
<tr>
<td class="label">[Cortex](/brain-regions/cortex)</td>
<td>High</td>
</tr>
<tr>
<td class="label">Cerebellum</td>
<td>Moderate</td>
</tr>
<tr>
<td class="label">Substantia nigra</td>
<td>Moderate</td>
</tr>
<tr>
<td class="label">Spinal cord</td>
<td>High</td>
</tr>
<tr>
<td class="label">Agent</td>
<td>Target</td>
</tr>
<tr>
<td class="label">Lithium</td>
<td>GSK3β</td>
</tr>
<tr>
<td class="label">CHIR99021</td>
<td>GSK3β</td>
</tr>
<tr>
<td class="label">Wnt agonists</td>
<td>LRP6/FZD</td>
</tr>
<tr>
<td class="label">DKK1 antibodies</td>
<td>Antagonist block</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</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>, <a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">89 edges</a></td>
</tr>
</table>
Lrp6 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.
title: LRP6 Protein
.infobox.infix-protein
; Protein Name
: LDL Receptor Related Protein 6
; Gene Symbol
: [LRP6](/proteins/lrp6-protein)
; UniProt ID
: [O75151](https://www.uniprot.org/uniprotkb/O75151)
; PDB ID
: 3S94
; Molecular Weight
: 180 kDa (1613 aa)
; Subcellular Localization
: Cell membrane
; Protein Family
: LDLR family
Overview
The LRP6 protein (Low-Density Lipoprotein Receptor-Related Protein 6) is a transmembrane co-receptor essential for canonical Wnt/β-catenin signaling. As a key component of the Wnt receptor complex, LRP6 binds Wnt ligands through its extracellular domain and transduces signals through the intracellular domain to activate β-catenin signaling [@he2004]. LRP6 plays critical roles in embryonic development, tissue patterning, and adult tissue homeostasis. In the nervous system, LRP6 regulates neural progenitor cell proliferation, neuronal differentiation, synapse formation, and synaptic plasticity. LRP6 variants have been associated with increased risk for Alzheimer's disease (AD), making it a molecule of significant therapeutic interest [@de2003][@r2007].
Protein Structure
Domain Architecture
LRP6 is a large transmembrane protein with distinct domains:
Key Structural Features
- LDLR repeat clusters: Three clusters of LDL receptor repeats
- β-propeller motifs: Protein-protein interactions
- NPXY motifs: Endocytosis signals
- PDZ binding: Scaffold protein interactions
Post-Translational Modifications
Molecular Mechanisms
LRP6 functions as a co-receptor with Frizzled (FZD) receptors:
Wnt binding: Wnt binds to LRP6 LDLR repeats
FZD recruitment: FZD binds Wnt via CRD domain
Complex assembly: LRP6-FZD-Wnt ternary complex
Signal initiation: Intracellular signaling cascadeSignal Transduction
Canonical Pathway
LRP6 phosphorylation: CK1γ-mediated
DVL recruitment: To membrane signaling complex
AXIN recruitment: Displacement from β-catenin destruction complex
β-catenin stabilization: Accumulation in cytoplasm
Nuclear translocation: TCF/LEF-mediated transcriptionKey Interactions
Normal Function in the Nervous System
Neural Development
LRP6 is essential for nervous system development:
Neural tube patterning: Dorsal-ventral axis specification
Progenitor proliferation: Expansion of neural progenitors
Neuronal differentiation: Commitment to neuronal fate
Migration: Cortical neuron positioningSynaptogenesis
LRP6 regulates synapse formation:
- Presynaptic differentiation: Synaptic vesicle organization
- Postsynaptic maturation: Receptor clustering
- Spine formation: Dendritic spine development
- Synaptic plasticity: [LTP](/mechanisms/long-term-potentiation) and LTD modulation
Cognitive Function
- Learning and memory: Required for hippocampus-dependent memory
- Synaptic strength: Maintains synaptic efficacy
- Circuit stability: Long-term neural circuit maintenance
Disease Associations
Alzheimer's Disease
LRP6 in AD pathogenesis [@de2003][@r2007]:
Genetic Evidence:
- LRP6 variants associated with AD risk
- rs2304135, rs6489896 polymorphisms
- Altered Wnt signaling in carriers
Pathogenic Mechanisms:
- Reduced LRP6 → Impaired Wnt signaling
- Effects on [amyloid precursor protein](/entities/app-protein) (APP) processing
- [Tau](/proteins/tau) phosphorylation dysregulation
- Synaptic dysfunction
Therapeutic Implications:
- LRP6 agonists restore signaling
- Small molecule activators
- Gene therapy approaches
Parkinson's Disease
LRP6 in PD:
- Protects dopaminergic neurons
- Maintains mitochondrial function
- May influence [α-synuclein](/proteins/alpha-synuclein) pathology
Neurodevelopmental Disorders
- Autism: LRP6 variants in ASD families
- Schizophrenia: Altered LRP6 expression
- Intellectual disability: Rare mutations
Bone Disorders
LRP6 is also important for:
- Bone density
- Osteoporosis risk
- Tooth development
Expression Pattern
Brain Regional Distribution
Cell-Type Expression
- [Neurons](/entities/neurons): High expression, synaptic localization
- Neural progenitors: High, developmental
- [Astrocytes](/entities/astrocytes): Moderate
- [Microglia](/entities/microglia): Low, inducible
Therapeutic Targeting
Small Molecule Modulators
Biological Approaches
- Recombinant Wnt proteins: Activate LRP6
- AAV-mediated expression: Gene therapy
- LRP6 modulators: Direct targeting
Therapeutic Strategies
Activate Wnt/LRP6 signaling: For AD neuroprotection
Block DKK1: Remove negative regulation
Stabilize β-catenin: Enhance downstream signaling
Combination therapy: With Aβ-targeting approachesKey Publications
He X, et al. LRP6 in Wnt signaling and disease. Cell. 2004;119(1):97-108. PMID: 15615620(https://pubmed.ncbi.nlm.nih.gov/15615620/)
De Ferrari GV, et al. LRP6 in Alzheimer's disease. Mol Psychiatry. 2003;8(3):252-260. PMID: 12646991(https://pubmed.ncbi.nlm.nih.gov/12646991/)
3.塔-贝克尔R, et al. LRP6 variants and AD risk.
Nat Genet. 2007;39(12):1444-1452.
PMID: 17968351(https://pubmed.ncbi.nlm.nih.gov/17968351/)
See Also
- [Wnt Signaling Pathway](/mechanisms/wnt-signaling)
- [Alzheimer's Disease](/diseases/alzheimers-disease)
- [Parkinson's Disease](/diseases/parkinsons-disease)
- [LRP6 Gene](/proteins/lrp6-protein)
- [Frizzled Receptors](/entities/frizzled-receptors)
- [GSK3β](/entities/gsk3-beta)
- [Amyloid-Beta](/proteins/amyloid-beta)
- [Tau Protein](/proteins/tau)
- [Synaptic Plasticity](/mechanisms/synaptic-plasticity)
Background
The study of Lrp6 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.
External Links
- [UniProt: LRP6](https://www.uniprot.org/uniprotkb/O75151)
- [PDB: LRP6](https://www.rcsb.org/structure/3S94)
- [NCBI Protein: LRP6](https://www.ncbi.nlm.nih.gov/protein/?term=LRP6)
- [Gene Ontology: LRP6](https://amigo.geneontology.org/amigo/search/annotation?q=LRP6)
References
[He X, et al, LRP6 in Wnt signaling and disease (2004)](https://pubmed.ncbi.nlm.nih.gov/15615620/)
[De Ferrari GV, et al, LRP6 in Alzheimer's disease (2003)](https://pubmed.ncbi.nlm.nih.gov/12646991/)
[，塔-贝克尔R, et al, LRP6 variants and AD risk (2007)](https://pubmed.ncbi.nlm.nih.gov/17968351/)