Ncam1 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.
Neural Cell Adhesion Molecule 1
| Protein Name | NCAM1 (Neural Cell Adhesion Molecule 1) |
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| Gene | NCAM1 |
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| UniProt ID | P13591 |
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| PDB ID | 3B07, 4JW9 |
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| Molecular Weight | 180-220 kDa (variable due to splicing) |
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| Subcellular Localization | Cell membrane (Type I membrane protein) |
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| Protein Family | Immunoglobulin superfamily, NCAM family |
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| Aliases | CD56, NCAM, Leu-19 |
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NCAM1 (Neural Cell Adhesion Molecule 1), also known as CD56, is a cell surface glycoprotein that mediates cell-cell adhesion in the nervous system. NCAM1 plays critical roles in neuronal development, synaptic formation, plasticity, and regeneration. It is one of the most abundant CAMs (Cell Adhesion Molecules) in the brain and is essential for proper brain development and function. NCAM1 has been implicated in various neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and psychiatric disorders.
NCAM1 is a highly glycosylated protein with complex domain architecture:
- N-terminal Signal Peptide: Targets protein for secretion/membrane insertion
- Five Ig-like Domains: Immunoglobulin-like domains (IgI-V) mediating homophilic binding
- Two Fibronectin Type III (FNIII) Repeats: Cell adhesion and signaling functions
- Transmembrane Domain: Single-pass membrane-spanning region
- Cytoplasmic Tail: Intracellular domain interacting with cytoskeletal proteins
NCAM1 undergoes extensive alternative splicing, producing multiple isoforms:
- NCAM-120: GPI-anchored form (120 kDa)
- NCAM-140: Transmembrane form (140 kDa)
- NCAM-180: Transmembrane form with extended cytoplasmic tail (180 kDa)
The extracellular Ig-like domains mediate homophilic (NCAM-NCAM) and heterophilic interactions with other proteins.
NCAM1 is essential for nervous system development and function:
- Homophilic Binding: NCAM1 binds to itself (NCAM-NCAM) on adjacent cells
- Synaptic Adhesion: Facilitates formation and maintenance of synapses
- Axon Guidance: Directs axon growth and pathfinding during development
- Neuronal Migration: Regulates neuronal positioning in developing brain
- Synapse Formation: Essential for excitatory and inhibitory synapse development
- LTP/LTD: NCAM1 polysialylation regulates synaptic plasticity
- Presynaptic Differentiation: Induces presynaptic specialization
- Postsynaptic Density: Interacts with PSD-95 and other scaffolding proteins
- FGFR Activation: NCAM1 activates fibroblast growth factor receptor
- ERK/MAPK Signaling: Triggers downstream signaling cascades
- Calcium Signaling: Modulates intracellular calcium dynamics
- Cytoskeletal Rearrangement: Links to actin cytoskeleton via p59fyn and other kinases
NCAM1 dysfunction contributes to AD pathogenesis:
- Synaptic Loss: Reduced NCAM1 expression correlates with synaptic density loss
- Amyloid-β Effects: Aβ interferes with NCAM1-mediated adhesion
- Tau Pathology: Tau pathology affects NCAM1 trafficking
- Cognitive Decline: NCAM1 levels correlate with cognitive performance
- Dopaminergic Neurons: NCAM1 expressed in substantia nigra neurons
- α-Synuclein Effects: α-Synuclein aggregation affects NCAM1 function
- Regeneration: NCAM1 promotes dopaminergic neuron regeneration
- Schizophrenia: NCAM1 polymorphisms associated with schizophrenia risk
- Bipolar Disorder: Altered NCAM1 expression in brain
- Depression: NCAM1 involvement in stress response
- Stroke: NCAM1 promotes neural regeneration post-stroke
- Traumatic Brain Injury: NCAM1 modulates injury response
- Epilepsy: Altered NCAM1 in epileptogenesis
| Approach |
Mechanism |
Development Stage |
Examples |
| NCAM1 Mimetics |
Soluble NCAM1 fragments |
Research |
C3 fragment |
| Peptide Agonists |
Activate NCAM1 signaling |
Preclinical |
FGL peptide |
| Gene Therapy |
AAV-NCAM1 delivery |
Preclinical |
AAV-NCAM1 |
| Small Molecules |
Enhance NCAM1 expression |
Discovery |
N/A |
- NCAM1 Knockout Mice: Show learning deficits and brain abnormalities
- Transgenic NCAM1 Mice: Overexpression enhances synaptic plasticity
- Conditional KO Models: Neuron-specific deletion reveals function
- AD Model Crosses: NCAM1 modification affects AD pathology
- Soluble NCAM1 (sNCAM1): Detected in CSF and blood
- CSF NCAM1: Marker of synaptic damage
- Serum NCAM1: Potential biomarker for neurodegeneration
- Polysialylation: Understanding the role of PSA-NCAM in plasticity
- Isoform-specific Functions: Different roles of NCAM-120/140/180
- Therapeutic Development: Targeting NCAM1 for neurodegeneration
- Regeneration: NCAM1 in neural repair strategies
- NCAM1 in synaptic plasticity and memory. Nat Rev Neurosci (2008)[1]
- NCAM1 and Alzheimer's disease. J Neurosci (2012)[2]
- NCAM1 in Parkinson's disease models. Brain (2015)[3]
- NCAM1 polysialylation in synaptic plasticity. Trends Neurosci (2018)[4]
- NCAM1 and neuropsychiatric disorders. Mol Psychiatry (2020)[5]
The study of Ncam1 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.
[1] Welzl H, et al. NCAM1 in synaptic plasticity and memory. Nat Rev Neurosci. 2008;9(7):559-567.
[2] Petit A, et al. NCAM1 deficiency in Alzheimer's disease. J Neurosci. 2012;32(46):16809-16821.
[3] Yang HJ, et al. NCAM1 in Parkinson's disease models. Brain. 2015;138(11):3222-3237.
[4] Bonfanti L, et al. Polysialylated NCAM in synaptic plasticity. Trends Neurosci. 2018;41(5):318-329.
[5] Brennecke P, et al. NCAM1 and neuropsychiatric disorders. Mol Psychiatry. 2020;25(8):1724-1737.
[6] Rønn LC, et al. The role of NCAM1 in neurodegeneration. Prog Neurobiol. 2021;199:102193.
Last updated: 2026-03-04