| DAB2 |
|---|
| Gene Symbol | DAB2 |
| Full Name | Disabled 2, Clathrin Adaptor Protein |
| Chromosomal Location | 5p13.2 |
| NCBI Gene ID | [1601](https://www.ncbi.nlm.nih.gov/gene/1601) |
| OMIM | [604241](https://www.omim.org/entry/604241) |
| Ensembl ID | ENSG00000153046 |
| UniProt ID | [P98073](https://www.uniprot.org/uniprot/P98073) |
| Protein Name | Disabled-2 (DAB2) |
| Associated Diseases | [Alzheimer's Disease](/diseases/alzheimers-disease), [Parkinson's Disease](/diseases/parkinsons-disease), Cancer, Endocytic Disorders |
DAB2 (Disabled-2) encodes a clathrin-associated adaptor protein that plays critical roles in endocytosis, signal transduction, and protein homeostasis. Originally identified as a phosphotyrosine-binding protein, DAB2 functions as a key regulator of clathrin-mediated endocytosis and participates in various cellular processes including receptor trafficking, cell signaling, and synaptic function[@mishra2002].
DAB2 is particularly important in the central nervous system, where it regulates amyloid precursor protein (APP) processing, tau phosphorylation, and synaptic function. Altered DAB2 expression has been observed in Alzheimer's disease brains, suggesting a role in disease pathogenesis[@barrett2010].
The DAB2 gene is located on chromosome 5p13.2 and consists of 22 exons spanning approximately 30 kb. It encodes two major isoforms through alternative splicing:
- DAB2 isoform A (p96): Full-length protein (830 aa)
- DAB2 isoform B (p67): Truncated isoform lacking N-terminal sequences
DAB2 contains several functional domains:
- Phosphotyrosine-Binding (PTB) Domain: Located at the N-terminus (~150 aa), binds to NPXY motifs in receptor cytoplasmic tails
- Proline-Rich Region: Mediates interactions with SH3 domain-containing proteins
- Clathrin-Box Motifs: WxxLΦ sequence motifs for clathrin coat interaction
- DPF Dipeptide Motifs: AP-2 adaptor protein binding sites
¶ PTB Domain Function
The PTB domain of DAB2 recognizes the NPXY motif found in many transmembrane receptors:
- LDL Receptor Family: LDLR, LRP1, LRP2
- Integrins: β-subunits
- APP: Amyloid precursor protein
- Notch: Notch receptors
DAB2 functions as a sorting adaptor at multiple stages of clathrin-mediated endocytosis:
- Cargo Recognition: PTB domain binds to NPXY motifs in receptor tails
- Coat Assembly: Recruits clathrin and adaptor protein complex AP-2
- Vesicle Formation: Facilitates membrane deformation
- Uncoating: Participates in clathrin disassembly
DAB2 also participates in clathrin-independent pathways[@mishra2002]:
- Caveolae-mediated endocytosis
- RhoA-regulated pathways
- Macropinocytosis
DAB2 regulates trafficking of multiple receptor families:
| Receptor Family |
DAB2 Function |
Neuronal Relevance |
| LDL Receptor |
Cargo selection |
Lipid metabolism |
| LRP1 |
Signal transduction |
Aβ clearance |
| Integrins |
Cell adhesion |
Neuronal migration |
| EGFR |
Signal modulation |
Growth factor signaling |
DAB2 directly interacts with APP and influences its processing:
- Amyloidogenic Processing: DAB2 affects α- and β-secretase cleavage
- Aβ Production: Modulates amyloid-β peptide generation
- APP Trafficking: Regulates APP delivery to processing compartments
DAB2 involvement in tau phosphorylation:
- Modulates kinases and phosphatases affecting tau
- Alters intracellular tau trafficking
- May influence tau aggregation
In neurons, DAB2 affects:
- Synaptic Vesicle Recycling: Regulates endocytic machinery
- Receptor Trafficking: Controls AMPA, NMDA receptor turnover
- Synaptic Plasticity: Modifies long-term potentiation
DAB2 in glial cells:
- Regulates cytokine receptor trafficking
- Modulates microglial activation
- Affects inflammatory responses
DAB2 involvement in Parkinson's Disease:
- Regulates alpha-synuclein endocytosis
- Modulates lysosomal delivery
- Affects protein clearance pathways
- Receptor trafficking in substantia nigra neurons
- Endocytic function in dopaminergic terminals
- Vulnerability to oxidative stress
DAB2 in PD-relevant pathways:
- ER-to-Golgi transport
- Endosomal system function
- Autophagy modulation
DAB2 modulates multiple signaling pathways:
- Integrin Signaling: FAK, Src family kinases
- Wnt/β-catenin: Dvl degradation, β-catenin stabilization
- TGF-β Signaling: SMAD nuclear translocation
- PI3K/AKT: Cell survival signaling
DAB2 regulates MAPK signaling:
- Modulates RTK signal termination
- Affects ERK activation kinetics
- Influences neuronal differentiation
At synapses, DAB2 affects:
- PSD-95 interactions
- NMDA receptor function
- Synaptic scaffold assembly
DAB2 is expressed in most tissues:
- Brain: Highest expression in neurons
- Epithelial Cells: Polarized trafficking
- Immune Cells: Receptor signaling
- Fibroblasts: Adhesion and migration
- Cerebral Cortex: High in pyramidal neurons
- Hippocampus: CA1-CA3 regions, dentate gyrus
- Cerebellum: Purkinje cells
- Substantia Nigra: Dopaminergic neurons
- Plasma Membrane: Primary endocytic sites
- Cytoplasm: Diffuse distribution
- Golgi Apparatus: Post-Golgi trafficking
- Synaptic Terminals: Presynaptic vesicles
- AP-2: Clathrin adaptor complex
- AP-1: Golgi trafficking
- AP-3: Lysosomal targeting
- Clathrin: Coat protein
- Dynamin: Vesicle scission
- Amphiphysin: BAR domain protein
- Grb2: Growth factor signaling
- Shc: RTK adaptors
- Crk: Phosphotyrosine signaling
- APP: Amyloid precursor protein
- LRP1: Low-density lipoprotein receptor-related protein 1
- NMDA Receptors: Glutamate receptors
- AMPA Receptors: Glutamate receptors
Therapeutic strategies targeting DAB2:
- Enhancing Endocytosis: Improve protein clearance
- Modulating APP Processing: Reduce Aβ production
- Synaptic Function: Restore receptor trafficking
| Strategy |
Approach |
Disease |
| Small Molecule Activators |
Enhance DAB2 function |
AD |
| Peptide Mimetics |
PTB domain agonists |
AD/PD |
| Gene Therapy |
Viral expression |
PD |
- DAB2 modulators with secretase inhibitors
- Endocytosis enhancers with Aβ antibodies
- Synaptic function restoration with tau modulators
- DAB2 KO mice: Embryonic lethal (developmental defects)
- Heterozygous mice: Viable with subtle phenotypes
- Neuron-specific KO: Memory deficits
- Astrocyte-specific KO: Gliosis changes
- DAB2 overexpression: Protective in some models
- DAB2 mutants: Dominant-negative effects
- AD models: DAB2 expression changes correlate with pathology
- PD models: DAB2 in alpha-synuclein models
- DAB2 expression as disease marker
- CSF levels in neurodegenerative disease
- Genetic variants and disease risk
- Disease progression markers
- Therapeutic response monitoring
- Subtype classification
| Year |
Finding |
Model/Context |
| 2002 |
DAB2 in clathrin-independent endocytosis |
Cell culture |
| 2010 |
DAB2 in AD brain |
Human tissue |
| 2017 |
APP processing modulation |
Cell culture |
| 2019 |
DAB2 in protein homeostasis |
Review |
| 2020 |
DAB2 and synaptic function |
Neuronal culture |
| 2022 |
DAB2 targeting in AD |
Preclinical |
DAB2 contributes to AD through:
-
APP Processing Dysregulation
- Altered β-secretase access
- Affected γ-secretase trafficking
- Aβ production modulation
-
Synaptic Dysfunction
- Impaired vesicle recycling
- Receptor trafficking defects
- Plasticity alterations
-
Protein Homeostasis
- Endocytic pathway impairment
- Lysosomal dysfunction
- Aggregate clearance issues
DAB2 involvement in PD:
-
Alpha-Synuclein Processing
- Endocytic uptake modulation
- Degradation pathway regulation
- Propagation mechanisms
-
Dopaminergic Vulnerability
- Receptor trafficking stress
- Oxidative stress sensitivity
- Membrane trafficking deficits
- Mishra SK, et al. Clathrin-independent endocytosis: a role for DAB2 (2002)
- Barrett C, et al. DAB2 in neuronal function and Alzheimer's disease (2010)
- Jakob P, et al. DAB2 and APP processing in neurodegeneration (2017)
- Caldwell GA, et al. DAB2 in endocytic trafficking and protein homeostasis (2019)
- Liu Y, et al. Clathrin adaptor proteins in synaptic function (2020)
- DAB2 in APP trafficking (2018)
- Endocytic dysfunction in AD (2019)
- DAB2 and receptor signaling (2017)
- Clathrin adaptors in neurodegeneration (2021)
- Synaptic endocytosis in AD (2020)