DNAJC6 (DnaJ Heat Shock Protein Family Member C6), also known as auxilin-2, is a neuronal-specific co-chaperone protein that plays essential roles in synaptic vesicle recycling and lysosomal function. Located on chromosome 19q13.43, this gene encodes a protein primarily expressed in neurons throughout the brain, with particularly high levels in the substantia nigra, basal ganglia, and cerebral cortex.
DNAJC6 is distinct from its relative DNAJC5 (cystinosin) in that it is neuron-specific and functions in both clathrin-mediated endocytosis and lysosomal homeostasis. Recessive loss-of-function mutations in DNAJC6 cause early-onset Parkinsonism, known as PARK19, typically manifesting before age 30.
Gene Symbol
DNAJC6
Full Name
DnaJ Heat Shock Protein Family (Hsp40) Member C6
Chromosomal Location
19q13.43
NCBI Gene ID
[NCBI Gene: 9829](https://www.ncbi.nlm.nih.gov/gene/9829)
OMIM
[OMIM: 613335](https://www.omim.org/entry/613335)
Ensembl ID
ENSG00000138193
UniProt ID
[Q9Y4X5](https://www.uniprot.org/uniprot/Q9Y4X5)
Associated Diseases
[Parkinson's Disease](/diseases/parkinsons-disease), [PARK19](/diseases/park19), [Early-Onset Parkinsonism](/diseases/early-onset-parkinsonism), [Juvenile Parkinsonism](/diseases/juvenile-parkinsonism)
Protein Aliases
Auxilin-2, DNAJC6
DNAJC6 encodes the auxilin-2 protein, a neuronal co-chaperone of the Hsp40 family that plays a critical role in synaptic vesicle endocytosis. Unlike its close relative DNAJC5 (cystinosin), DNAJC6/Auxilin-2 is specifically expressed in neuronal tissues and regulates clathrin-mediated endocytosis.
Key Functions in Synaptic Vesicle Cycling:
- Clathrin Uncoating: Auxilin-2 facilitates clathrin coat disassembly during synaptic vesicle recycling, acting as a co-chaperone with Hsc70 to disassemble clathrin triskelia
- Synaptic Transmission: Critical for maintaining synaptic vesicle pools and neurotransmitter release
- Neuronal Homeostasis: Regulates endocytic trafficking in presynaptic terminals
¶ Lysosomal Function and Autophagy
Beyond its role in synaptic vesicle recycling, DNAJC6 is increasingly recognized as a critical regulator of lysosomal function. Recent research (PMID: 41820376) demonstrates that DNAJC6 truncation mutants cause lysosomal deficiency-induced upregulation of pathologic alpha-synuclein.
Mechanisms:
- DNAJC6 localizes to lysosomes and participates in autophagic flux
- Loss-of-function mutations impair lysosomal degradation capacity
- Lysosomal dysfunction leads to accumulation of toxic protein aggregates
- The connection to alpha-synuclein pathology is a key disease mechanism
DNAJC6 mutations cause PARK19, an autosomal recessive form of early-onset Parkinson's disease. Key characteristics include:
- Inheritance: Autosomal recessive (biallelic loss-of-function mutations)
- Early onset: Typically before age 30, often in adolescence or early adulthood
- Rapid progression: Early development of motor complications
- Good levodopa response: Patients respond well to dopaminergic therapy
- Additional features: Some patients develop cognitive impairment and psychiatric symptoms
DNAJC6 mutations are among the genetic causes of juvenile-onset Parkinsonism (<20 years), along with PARK2 (parkin/PRKN) and PINK1 mutations.
DNAJC6 loss-of-function leads to neurodegeneration through multiple interconnected mechanisms:
- Impaired synaptic vesicle recycling
- Accumulation of clathrin-coated vesicles
- Depletion of synaptic vesicle pools
- Progressive dopaminergic neuron dysfunction
- Reduced lysosomal enzyme activity
- Impaired autophagic flux
- Accumulation of undigested cellular debris
- Lysosomal deficiency exacerbates protein aggregate formation
The connection to alpha-synuclein is critical:
- Lysosomal deficiency leads to impaired clearance of alpha-synuclein
- Pathologic alpha-synuclein accumulates in neurons
- Forms Lewy bodies characteristic of Parkinson's disease
- Spreads throughout the nervous system in a prion-like manner
Understanding DNAJC6 function opens several therapeutic avenues:
- Gene therapy: Viral delivery of wild-type DNAJC6 to restore function
- Lysosomal enhancement: Small molecules to boost lysosomal activity
- Alpha-synuclein targeting: Immunotherapies to reduce toxic aggregates
- Neuroprotective strategies: Supporting synaptic and lysosomal homeostasis
DNAJC6 shows neuron-specific expression:
- Brain: Highest expression in cerebral cortex, hippocampus, basal ganglia, and substantia nigra
- Peripheral nervous system: Present in dorsal root ganglia
- Cellular localization: Cytosolic, associated with clathrin-coated vesicles and lysosomes
DNAJC6 expression patterns from Allen Brain Atlas:
- Cerebral cortex - High expression in pyramidal neurons (layer 2/3 and layer 5)
- Hippocampus - High expression in CA1 pyramidal neurons and dentate gyrus
- Basal ganglia - High expression in striatum and substantia nigra
- Cerebellum - Moderate expression in Purkinje cells
DNAJC6 is expressed in:
- Pyramidal neurons (SLC17A7+)
- GABAergic interneurons
- Dopaminergic neurons
- Astrocytes
| Region |
Expression Level |
Data Source |
| Cortex |
High |
Mouse Brain |
| Hippocampus |
High |
Mouse Brain |
| Striatum |
High |
Mouse Brain |
| Substantia nigra |
Medium |
Human MTG |
| Cerebellum |
Medium |
Mouse Brain |