DNAJC26 (also known as G3BP2 - Ras GTPase-Activating Protein-Binding Protein 2) is a stress granule-associated protein that plays critical roles in RNA metabolism, stress response, and protein homeostasis. It is a member of the DNAJ/Hsp40 family of molecular chaperones and has been increasingly recognized for its involvement in neurodegenerative diseases, particularly amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD).
| Property |
Value |
| Gene Symbol |
DNAJC26 (G3BP2) |
| Gene Name |
DnaJ Heat Shock Protein Family Member C26 |
| Aliases |
G3BP2, RAS-GTPASE-ACTIVATING PROTEIN-BINDING PROTEIN 2 |
| Chromosomal Location |
4p16.3 |
| NCBI Gene ID |
9907 |
| OMIM |
604393 |
| UniProt |
Q9UQF2 |
DNAJC26/G3BP2 is a central component of stress granules (SGs), membrane-less organelles that form in response to cellular stress. Key functions include:
- mRNA Binding and Regulation — G3BP2 binds to specific mRNA sequences and regulates translation during stress
- Stress Granule Assembly — Acts as a scaffold protein, nucleating stress granule formation through interactions with multiple SG components
- Translation Repression — Participates in mechanisms that stall translation under stress conditions
- mRNA Decay — Associates with machinery involved in mRNA degradation pathways
G3BP2 interacts with several proteins relevant to neurodegeneration:
- TDP-43 — Sequestration of TDP-43 in stress granules is a hallmark of ALS/FTD
- FUS — Another ALS/FTD-associated protein that localizes to stress granules
- TGF-β Signaling — Modulates cellular signaling pathways relevant to neuroinflammation
DNAJC26/G3BP2 is genetically and functionally linked to ALS:
- Genetic Associations — Rare variants in DNAJC26 have been identified in ALS patients
- Stress Granule Dysregulation — G3BP2-positive stress granules are altered in ALS, with abnormal persistence and composition
- Protein Aggregation — G3BP2 is found in pathological inclusions in ALS/FTD brains
- G3BP2 pathology is observed in FTD subtypes, particularly in cases with TDP-43 pathology
- Stress granule dysfunction contributes to the characteristic protein aggregation in FTD
- Protein Homeostasis Failure — G3BP2 dysfunction impairs the cellular machinery for protein quality control
- RNA Metabolism Defects — Altered mRNA processing contributes to neuronal vulnerability
- Oxidative Stress Response — G3BP2's role in oxidative stress response is relevant to age-related neurodegeneration
DNAJC26 shows broad expression across tissues:
- Brain — High expression in neurons, particularly in cortex and motor neurons
- Spinal Cord — Notable expression in motor neuron populations affected in ALS
- Peripheral Tissues — Moderate expression in various tissues
DNAJC26/G3BP2 represents a potential therapeutic target:
- Stress Granule Modulators — Compounds that normalize stress granule dynamics
- Small Molecule Inhibitors — Agents targeting G3BP2-protein interactions
- G3BP2 in cerebrospinal fluid (CSF) may serve as a biomarker for neurodegeneration
- Stress granule markers could indicate disease progression