L1CAM (L1 Cell Adhesion Molecule)

L1CAM (L1 Cell Adhesion Molecule)

Introduction

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">L1CAM (L1 Cell Adhesion Molecule)</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>L1CAM</td>
</tr>
<tr>
<td class="label">Chromosome</td>
<td>Xq28</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>3909</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>[P32004](https://www.uniprot.org/uniprot/P32004)</td>
</tr>
<tr>
<td class="label">Protein Class</td>
<td>Immunoglobulin superfamily CAM</td>
</tr>
<tr>
<td class="label">Expression</td>
<td>CNS (neurons, glia), PNS, developing brain</td>
</tr>
<tr>
<td class="label">Partner</td>
<td>Interaction Type</td>
</tr>
<tr>
<td class="label">Ankyrin-G</td>
<td>Cytoplasmic tail binding</td>
</tr>
<tr>
<td class="label">Integrins (α5β1, αvβ3)</td>
<td>Heterophilic</td>
</tr>
<tr>
<td class="label">TAG-1/Axonin-1</td>
<td>Heterophilic</td>
</tr>
<tr>
<td class="label">APP</td>
<td>Heterophilic</td>
</tr>
<tr>
<td class="label">Fyn/Src</td>
<td>Signaling kinases</td>
</tr>
<tr>
<td class="label">Strategy</td>
<td>Approach</td>
</tr>
<tr>
<td class="label">Gene therapy</td>
<td>AAV-L1CAM for L1 syndrome</td>
</tr>
<tr>
<td class="label">Small molecule signaling</td>
<td>Enhancing L1CAM-mediated plasticity</td>
</tr>
<tr>
<td class="label">**Biomarker

L1CAM (L1 Cell Adhesion Molecule)

Introduction

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">L1CAM (L1 Cell Adhesion Molecule)</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>L1CAM</td>
</tr>
<tr>
<td class="label">Chromosome</td>
<td>Xq28</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>3909</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>[P32004](https://www.uniprot.org/uniprot/P32004)</td>
</tr>
<tr>
<td class="label">Protein Class</td>
<td>Immunoglobulin superfamily CAM</td>
</tr>
<tr>
<td class="label">Expression</td>
<td>CNS (neurons, glia), PNS, developing brain</td>
</tr>
<tr>
<td class="label">Partner</td>
<td>Interaction Type</td>
</tr>
<tr>
<td class="label">Ankyrin-G</td>
<td>Cytoplasmic tail binding</td>
</tr>
<tr>
<td class="label">Integrins (α5β1, αvβ3)</td>
<td>Heterophilic</td>
</tr>
<tr>
<td class="label">TAG-1/Axonin-1</td>
<td>Heterophilic</td>
</tr>
<tr>
<td class="label">APP</td>
<td>Heterophilic</td>
</tr>
<tr>
<td class="label">Fyn/Src</td>
<td>Signaling kinases</td>
</tr>
<tr>
<td class="label">Strategy</td>
<td>Approach</td>
</tr>
<tr>
<td class="label">Gene therapy</td>
<td>AAV-L1CAM for L1 syndrome</td>
</tr>
<tr>
<td class="label">Small molecule signaling</td>
<td>Enhancing L1CAM-mediated plasticity</td>
</tr>
<tr>
<td class="label">Biomarker development</td>
<td>Soluble L1CAM as AD diagnostic</td>
</tr>
<tr>
<td class="label">Remyelination enhancement</td>
<td>L1CAM agonists for MS</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a>, <a href="/wiki/dementia" style="color:#ef9a9a">Dementia</a>, <a href="/wiki/parkinson" style="color:#ef9a9a">Parkinson</a>, <a href="/wiki/tumor" style="color:#ef9a9a">Tumor</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">23 edges</a></td>
</tr>
</table>

L1CAM (L1 Cell Adhesion Molecule) is a neural cell adhesion molecule that plays critical roles in neuronal development, axonal guidance, myelination, and synaptic plasticity. As a member of the immunoglobulin superfamily, L1CAM mediates cell-cell adhesion through homophilic and heterophilic interactions, activating downstream signaling cascades that regulate cytoskeletal dynamics and gene expression.

Dysfunction of L1CAM contributes to multiple neurological disorders, including neurodevelopmental conditions (L1 syndrome, corpus callosum agenesis), neurodegenerative diseases (Alzheimer's disease, multiple sclerosis), and peripheral neuropathies.

Gene Overview

Protein Structure

L1CAM is a ~1400-amino acid transmembrane glycoprotein with:

• N-terminal signal peptide: Leader sequence for secretion/membrane targeting
• Immunoglobulin domain (Ig1-Ig6): Six Ig-like domains for homophilic and heterophilic binding
• Fibronectin type III repeats (FN1-FN5): Three repeats mediating extracellular interactions
• Single transmembrane domain: Spans the neuronal membrane
• C-terminal cytoplasmic tail: Contains ankyrin-binding site and signaling motifs

Molecular Function

Cell Adhesion and Signaling

L1CAM mediates multiple functions through protein-protein interactions:

Key Molecular Interactions

Disease Associations

L1 Syndrome (Neurodevelopmental)

L1 syndrome encompasses X-linked disorders caused by L1CAM mutations:

• Corpus callosum agenesis: Partial or complete absence of the corpus callosum
• Hydrocephalus: Ventriculomegaly, often requiring shunting
• Intellectual disability: Variable severity, ranging from mild to profound
• Adducted thumbs: Characteristic claw-like hand posturing
• Developmental delay: Motor and language delays

Alzheimer's Disease

L1CAM plays multifaceted roles in AD pathogenesis:

• APP interaction: L1CAM binds to APP and influences amyloid-β processing
• Synaptic plasticity: Required for activity-dependent synaptic remodeling
• Cognitive function: L1CAM deficiency in neurons impairs cognition
• Potential biomarker: Soluble L1CAM being investigated as AD biomarker

Multiple Sclerosis

In MS, L1CAM participates in:

• Remyelination: Critical for oligodendrocyte precursor migration
• Axonal regeneration: Required for successful axon regeneration after injury
• Inflammatory demyelination: Altered L1CAM expression in MS lesions

Peripheral Neuropathies

L1CAM mutations contribute to:

• Charcot-Marie-Tooth disease: X-linked CMT2 form
• ACTRT1-Related Neuropathy: Atypical presentations

Expression Pattern

L1CAM exhibits dynamic expression:

• Developing CNS: High in neuronal precursors, growing axons, migrating neurons
• Adult CNS: Cortical pyramidal neurons, hippocampal CA1/CA3 neurons, cerebellar Purkinje cells
• White matter: Axonal tracts (corpus callosum, corticospinal tract)
• PNS: Dorsal root ganglion neurons, peripheral nerve axons
• Non-neural: Some epithelial and endothelial cells

Mechanism Diagram

Therapeutic Implications

See Also

• [L1CAM Protein](/proteins/l1cam-protein)
• [Corpus Callosum](/brain-regions/corpus-callosum)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Multiple Sclerosis](/diseases/multiple-sclerosis)

References

Pathway Diagram

The following diagram shows the key molecular relationships involving L1CAM (L1 Cell Adhesion Molecule) discovered through SciDEX knowledge graph analysis: