Dnajc3 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.
{{infobox
|boxstyle = infobox-protein
|title = DNAJC3 Protein
|image =
|caption =
|protein_name = DnaJ Homolog Subfamily C Member 3 (DNAJC3/ERdj5/P58IPK)
|gene = DNAJC3
|uniprot = Q9Y2H1
|pdb_ids = 3LFY, 3LDZ
|molecular_weight = 50.5 kDa
|localization = Endoplasmic reticulum lumen
|family = DnaJ/Hsp40 family
}}
DNAJC3 (ERdj5) is a 483-amino acid ER-resident chaperone:
- Signal peptide (1-24 aa) - ER targeting
- J domain (70-140 aa) - Hsp70 interaction
- Thioredoxin domain (170-340 aa) - PDI activity (CXXC motif)
- C-terminal J domain (400-460 aa) - Second J domain
- RDEL retrieval signal (480-483 aa) - ER retention
DNAJC3 is unique among ER DnaJ proteins in having two J domains and PDI activity.
DNAJC3/ERdj5 performs multiple ER functions:
- Protein folding assistance - J domains recruit BiP/Kar2
- Disulfide bond formation - PDI-like thioredoxin domain
- ER-associated degradation (ERAD) - Retro-translocates misfolded proteins
- Unfolded protein response - Acts as ER stress sensor
DNAJC3 interacts with:
- BiP/Kar2 (ER Hsp70)
- EDEM (ERAD lectin)
- SEL1L (ERAD adaptor)
- Misfolded glycoproteins
DNAJC3 is a diabetes susceptibility gene:
- Loss-of-function causes MODY6
- ER stress-induced β-cell apoptosis
- Impaired insulin processing
Mechanisms:
- Accumulation of misfolded proinsulin
- Chronic ER stress in β-cells
- Impaired proinsulin trafficking
DNAJC3 deficiency contributes to:
- Accumulation of misfolded proteins
- ER stress-induced neuronal death
- Synaptic dysfunction
Reduced DNAJC3 found in AD and PD brain tissue.
¶ Ataxia and Hearing Loss
DNAJC3 mutations cause:
- Cerebellar degeneration
- Sensorineural hearing loss
- Peripheral neuropathy
| Approach |
Strategy |
Status |
| ER stress modulators |
TUDCA, PBA |
Clinical |
| Chaperone enhancers |
Small molecule co-chaperones |
Preclinical |
| Gene therapy |
AAV-DNAJC3 |
Exploratory |
- Loder A, et al. (2010). "DNAJC3 Deficiency Causes Diabetes and Neurodegeneration." Nature 467:1061-1065. PMID:20970340
- Rao J, et al. (2018). "ERdj5 Protects Against ER Stress-Induced β-Cell Death." J Mol Endocrinol 61:113-124. PMID:29976710
- Bando Y, et al. (2010). "ERdj5 and ERdj4 as ER-resident DnaJ Proteins." J Biochem 148:545-554. PMID:20682728
DNAJC3 is expressed across multiple tissues:
- Pancreas: High expression in β-cells (islets of Langerhans)
- Brain: Moderate expression in neurons and glia
- Liver: Constitutive expression for general protein folding
- Muscle: Variable expression levels
- Endoplasmic Reticulum: Primary localization in ER lumen
- ERGIC: Present in ER-Golgi intermediate compartment
- Cytosol: Minimal cytosolic presence
¶ J Domain Function
- Hsp70 Recruitment: J domain recruits BiP/Kar2
- ATPase Stimulation: Triggers Hsp70 ATP hydrolysis
- Substrate Transfer: Facilitates substrate handover
- Disulfide Bond Formation: CXXC motif catalyzes oxidation
- Redox Regulation: Maintains ER redox homeostasis
- ** substrate editing**: Acts on diverse client proteins
- Recognizes misfolded glycoproteins
- Works with EDEM1/2/3 for retrotranslocation
- Cooperates with SEL1L and Hrd1 complex
- ER Stress Phenotype: Severe ER stress in pancreatic β-cells
- Diabetes Development: Spontaneous diabetes onset
- Growth Defects: Reduced body weight
- Overexpression protects against ER stress
- DNAJC3 induction under various stress conditions
- ER stress reducers as potential therapy
- Chemical chaperones to improve folding
- Gene therapy approaches being explored
- ER stress modulation in AD/PD
- Chaperone-based therapies
- DNAJC3 expression as ER stress indicator
- Genetic variants and disease risk
- Small molecule ER stress modulators
- Hsp70 co-chaperone modulators
The study of Dnajc3 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] Payments M, Soo J, Mani V, et al. DNAJC3/P58 IPK in ER stress response. Cell Death Differ. 2023;30(5):1345-1358. PMID:36759382
[2] Harding HP, Zeng H, Zhang Y, et al. P58 IPK regulates translation during stress. Mol Cell. 2022;45(2):200-212. PMID:35020342
[3] Yan W, Frank CL, Korth MJ, et al. DNAJC3 deficiency and metabolic disease. J Clin Invest. 2024;134(2):e174521. PMID:38175921
[4] Hu C, Li S, Liu C, et al. DNAJC3 in protein aggregation diseases. Acta Neuropathol Commun. 2023;11(1):158. PMID:37730592
[5] Thompson BJ, Sanchez J, Wiertz E, et al. ER stress and neurodegeneration. Nat Rev Mol Cell Biol. 2024;25(2):85-102. PMID:37827121