ADAM10 (A Disintegrin And Metalloproteinase Domain-Containing Protein 10) is a gene located on chromosome 15q21.3 that encodes the principal α-secretase responsible for the non-amyloidogenic cleavage of the Amyloid Precursor Protein (APP). By cleaving APP within the amyloid-beta domain, ADAM10 precludes the generation of toxic amyloid-beta peptides, making it a key protective factor against Alzheimer's Disease (AD) [@potential2009][@adam2014].
ADAM10 is a member of the ADAM (A Disintegrin And Metalloproteinase) family of transmembrane proteins, which play important roles in cell adhesion, proteolysis, and signaling. As the constitutive α-secretase in neurons, ADAM10 is essential for maintaining the balance between amyloidogenic and non-amyloidogenic APP processing—a balance that is central to the amyloid hypothesis of AD pathogenesis.
Loss-of-function mutations in ADAM10 have been identified in families with both late-onset and early-onset Alzheimer's Disease, establishing it as a bona fide AD susceptibility gene [@secretase2020]. The therapeutic potential of ADAM10 modulation has been extensively investigated, as enhancing ADAM10 activity could simultaneously reduce toxic Aβ production and increase neuroprotective sAPPα levels [@therapeutic2023].
| Attribute | Value | Reference |
|---|---|---|
| Gene Symbol | ADAM10 | [@kuhn2010] |
| Full Name | A Disintegrin And Metalloproteinase Domain 10 | [@saftig2009] |
| Chromosomal Location | 15q21.3 | [@potential2009] |
| NCBI Gene ID | 102 | |
| Ensembl ID | ENSG00000137845 | |
| UniProt ID | O14672 | |
| OMIM | 602192 | |
| Protein Length | 748 amino acids |
ADAM10 is synthesized as a 748-amino-acid zymogen with the following domain structure [@saftig2009]:
Prodomain (residues 1-214): Functions as an intramolecular chaperone for proper folding; removed by furin/proprotein convertases during maturation. AD mutations Q170H and R181G reside in this domain [@adam2014].
Metalloproteinase domain (residues 215-467): Contains the catalytic zinc-binding motif HEXXHXXGXXH that mediates substrate cleavage. The catalytic zinc ion (Zn²⁺) is essential for proteolytic activity.
Disintegrin domain (residues 468-535): Participates in substrate recognition and cell-cell interactions. Contains an RGD sequence motif that can mediate integrin binding.
Cysteine-rich domain (residues 536-654): Mediates protein-protein interactions and contributes to substrate specificity.
Transmembrane domain (residues 655-677): Single-pass membrane anchor (type I membrane protein).
Cytoplasmic tail (residues 678-748): Contains regulatory motifs including a PDZ-binding motif and serine/threonine phosphorylation sites that regulate trafficking and activity.
The metalloproteinase domain contains the HExxHxxGxxH zinc-binding motif coordinated to a catalytic zinc ion. The mechanism involves:
ADAM10 is a promiscuous "sheddase" that cleaves the ectodomains of numerous transmembrane proteins [@deuss2018]:
| Substrate | Function | Relevance |
|---|---|---|
| APP (Amyloid Precursor Protein) | Non-amyloidogenic cleavage → sAPPα | AD protection |
| Notch receptors | Signaling, neurodevelopment | Development |
| N-cadherin | Cell adhesion, synaptic plasticity | Synapse function |
| E-cadherin | Cell-cell adhesion | Tissue integrity |
| EphA receptors | Axon guidance, synaptogenesis | Neural development |
| TREM2 | Microglial activation | AD biomarker |
| Prion protein (PrP) | Cellular homeostasis | Prion disease |
| IL-6R | Inflammation | Immune modulation |
| TNF-α | Pro-inflammatory cytokine | Inflammation |
ADAM10 cleaves APP between residues Lys⁶⁸⁷ and Leu⁶⁸⁸ (within the Aβ sequence), generating:
This cleavage precludes Aβ generation because it cuts within the Aβ peptide domain [@postina2001][@zurhove2008].
The released sAPPα ectodomain has multiple neuroprotective properties:
ADAM10 and BACE1 (β-secretase) compete for APP substrate at the cell surface and in endosomes [@seyfried2010]. The relative activity of these two enzymes determines the balance between:
This balance is central to AD pathogenesis.
ADAM10 is required for Notch receptor activation through proteolytic cleavage [@saftig2009]:
This pathway is essential for:
ADAM10 mutations are linked to Alzheimer's Disease through loss of α-secretase function:
Prodomain Missense Mutations (Late-Onset AD):
| Mutation | Effect | Evidence |
|---|---|---|
| p.Q170H | >70% reduced α-secretase activity; 1.5-3.5x elevated Aβ | Found in 7 LOAD families [@potential2009] |
| p.R181G | Similar reduction in activity; elevated Aβ | Found in 4 LOAD families [@adam2014] |
| p.Tyr167* | Truncated non-functional protein | Nonsense mutation in FAD family [@secretase2020] |
Mechanism: These missense mutations impair the intramolecular chaperone function of the ADAM10 prodomain, leading to:
In Vivo Evidence: In Tg2576 AD transgenic mice, both Q170H and R181G mutations attenuated ADAM10 α-secretase activity, shifted APP processing toward β-secretase-mediated cleavage, and enhanced Aβ plaque burden and reactive gliosis [@adam2014].
ADAM10 is a prime therapeutic target for AD because enhancing its activity could simultaneously:
| Strategy | Mechanism | Status |
|---|---|---|
| Retinoids (Acitretin) | Transcriptional upregulation | Phase II trial (increased CSF sAPPα) [@therapeutic2023] |
| PPARγ agonists | Increase ADAM10 expression | Preclinical |
| LXR/RXR agonists | Transcriptional activation | Preclinical |
| HDAC inhibitors | Epigenetic derepression | Preclinical |
| Etazolate (EHT 0202) | Direct activation | Phase II trials |
| BACE1 inhibition | Indirectly favor α-cleavage | Failed (off-target toxicity) |
ADAM10 is widely expressed in the central nervous system:
| Region | Expression Level | Cell Types |
|---|---|---|
| Cerebral cortex | High | Pyramidal neurons, interneurons |
| Hippocampus | High | CA1, CA3 pyramidal cells, dentate gyrus granule cells |
| Cerebellum | High | Purkinje cells |
| Thalamus | Moderate | Various neuron populations |
| Basal ganglia | Moderate | Medium spiny neurons |
| Substantia nigra | Moderate | Dopaminergic neurons |
ADAM10 activity is regulated at multiple levels [@endres2017]:
APP (transmembrane)
↓
├─→ ADAM10 (α-secretase) → sAPPα + C83 (non-amyloidogenic)
│
└─→ BACE1 (β-secretase) → sβAPP + C99 → γ-secretase → Aβ (amyloidogenic)
| Pathway | Interaction |
|---|---|
| Notch signaling | ADAM10 is primary Notch sheddase |
| Wnt/β-catenin | Cross-talk in neuroprotection |
| MAPK/ERK | Activity-regulated ADAM10 |
| PKC | Phosphorylation modulates activity |
| Model | Description | Key Findings |
|---|---|---|
| ADAM10 knockout mice | Complete loss of ADAM10 | Lethal, developmental defects |
| Conditional neuronal KO | Neuron-specific deletion | Impaired memory, increased Aβ |
| ADAM10 overexpressing mice | Neuronal overexpression | Reduced Aβ, improved cognition |
| Q170H knock-in | Patient mutation | Impaired α-secretase activity |