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.
.infobox.infix-protein
; Protein Name
: LDL Receptor Related Protein 6
; Gene Symbol
: LRP6
; UniProt ID
: O75151
; PDB ID
: 3S94
; Molecular Weight
: 180 kDa (1613 aa)
; Subcellular Localization
: Cell membrane
; Protein Family
: LDLR family
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 [1]. 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 [2][3].
LRP6 is a large transmembrane protein with distinct domains:
| Domain | Position | Function |
|---|---|---|
| Signal peptide | 1-23 aa | ER targeting |
| LDLR repeats 1-3 | 24-600 aa | Wnt binding |
| LDLR repeats 4-6 | 600-900 aa | Wnt binding |
| EGF-like domains | 900-1200 aa | Ligand interaction |
| Transmembrane | 1380-1402 aa | Membrane anchoring |
| Cytoplasmic tail | 1403-1613 aa | Signal transduction |
| Modification | Site | Functional Consequence |
|---|---|---|
| Phosphorylation | S1490, T1479 | β-catenin activation |
| Glycosylation | Multiple | Stability |
| Palmitoylation | C1351 | Membrane association |
| Ubiquitination | Multiple | Turnover regulation |
LRP6 functions as a co-receptor with Frizzled (FZD) receptors:
| Partner | Interaction Domain | Function |
|---|---|---|
| Wnt proteins | LDLR repeats | Ligand binding |
| FZD receptors | Extracellular | Complex formation |
| DVL | Cytoplasmic | Signal transduction |
| AXIN | Cytoplasmic | Destruction complex |
| GSK3β | Cytoplasmic | Kinase regulation |
LRP6 is essential for nervous system development:
LRP6 regulates synapse formation:
LRP6 in AD pathogenesis [2:1][3:1]:
Genetic Evidence:
Pathogenic Mechanisms:
Therapeutic Implications:
LRP6 in PD:
LRP6 is also important for:
| Region | Expression Level | Cell Types |
|---|---|---|
| Hippocampus | Very high | Pyramidal neurons |
| Cortex | High | Pyramidal neurons |
| Cerebellum | Moderate | Purkinje cells |
| Substantia nigra | Moderate | Dopaminergic neurons |
| Spinal cord | High | Motor neurons |
| Agent | Target | Status | Notes |
|---|---|---|---|
| Lithium | GSK3β | Approved | Indirect LRP6 activation |
| CHIR99021 | GSK3β | Preclinical | Selective inhibitor |
| Wnt agonists | LRP6/FZD | Discovery | Direct activators |
| DKK1 antibodies | Antagonist block | Research | Remove inhibition |
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.
He X, et al. LRP6 in Wnt signaling and disease. Cell. 2004;119(1):97-108. PMID:15615620 ↩︎
De Ferrari GV, et al. LRP6 in Alzheimer's disease. Mol Psychiatry. 2003;8(3):252-260. PMID:12646991 ↩︎ ↩︎
，塔-贝克尔R, et al. LRP6 variants and AD risk. Nat Genet. 2007;39(12):1444-1452. PMID:17968351 ↩︎ ↩︎