| PRKN — Parkin RBR E3 Ubiquitin Protein Ligase | |
|---|---|
| Symbol | PRKN |
| Full Name | Parkin RBR E3 Ubiquitin Protein Ligase |
| Chromosome | 6q26 |
| NCBI Gene | 5071 |
| Ensembl | ENSG00000185348 |
| OMIM | 602544 |
| UniProt | O60260 |
| Diseases | [Parkinson's Disease](/diseases/parkinsons-disease), [Parkinsonism](/diseases/parkinsonsism), [Lysosomal Storage Disorders](/diseases/lysosomal-storage-disorders) |
| Expression | Substantia nigra, Striatum, [Cortex](/brain-regions/cortex), Heart, Skeletal muscle |
| Key Functions | |
| E3 ubiquitin ligase Mitochondrial quality control Mitophagy |
|
PRKN (Parkin RBR E3 Ubiquitin Protein Ligase), commonly known as Parkin, is a gene located on chromosome 6q26 that encodes an E3 ubiquitin ligase essential for mitochondrial quality control and mitophagy[1]. Pathogenic mutations in PRKN are among the most common causes of autosomal recessive early-onset Parkinson's disease (PD), accounting for approximately 50% of familial PD cases and 10-20% of early-onset sporadic PD[2].
Parkin functions as a key mediator of the PINK1-Parkin pathway, which senses mitochondrial damage and targets dysfunctional mitochondria for degradation through mitophagy[3]. This pathway is particularly important in dopaminergic neurons of the substantia nigra, which have high metabolic demands and are particularly vulnerable to mitochondrial dysfunction.
The discovery of PRKN mutations in familial Parkinson's disease in 1998 provided the first genetic link to mitochondrial dysfunction in PD pathogenesis, establishing the mitochondrial cascade hypothesis of PD[4].
Parkin is a 465-amino acid protein belonging to the RBR (Ring-Between-Ring) family of E3 ubiquitin ligases[5]:
Parkin catalyzes multiple types of ubiquitin linkages:
This versatility allows Parkin to coordinate both proteasomal and autophagic degradation pathways.
The PINK1-Parkin pathway is the primary mechanism for mitochondrial quality control[3:1][6]:
The PINK1-Parkin pathway is critical for:
Over 200 pathogenic PRKN mutations cause autosomal recessive Parkinson's disease[7]:
Parkin deficiency leads to PD through several mechanisms[8]:
Key Parkin substrates include[9]:
Pharmaceutical companies are developing Parkin-activating compounds[10]:
Therapeutic strategies targeting this pathway include:
Parkin is expressed throughout the brain and peripheral tissues:
| Tissue | Expression Level |
|---|---|
| Substantia nigra | High |
| Striatum | High |
| Cerebral cortex | Moderate |
| Hippocampus | Moderate |
| Heart | High |
| Skeletal muscle | High |
The high expression in dopaminergic neurons correlates with their vulnerability in PD.
Parkin mutations may modify disease severity in:
PARKIN acts as a tumor suppressor:
Parkin dysfunction exacerbates:
PRKN (Parkin) expression:
PRKN expressed in:
Kitada T, Asakawa S, Hattori N, et al. Mutations in the parkin gene cause autosomal recessive juvenile parkinsonism. Nature. 1998. ↩︎
Singleton AB, Farrer MJ, Bonifati V. The genetics of Parkinson's disease: progress and therapeutic implications. Nature Reviews Neurology. 2012. ↩︎
Pickrell AM, Youle RJ. The roles of PINK1, parkin, and mitochondrial fidelity in Parkinson's disease. Neuron. 2015. ↩︎ ↩︎
Trancikova A, Tsika E, Moore DJ. Mitochondrial dysfunction in genetic animal models of Parkinson's disease. Molecular Neurobiology. 2011. ↩︎
Riley BE, Lougheed JC, Callaway K, et al. Structure and function of Parkin RBR domain. Journal of Biological Chemistry. 2013. ↩︎
Narendra D, Tanaka A, Suen DF, Youle RJ. Parkin is recruited selectively to impaired mitochondria. Journal of Cell Biology. 2008. ↩︎
Pugliese R, Santos JD, Mendes F, et al. Parkinson's disease-associated genetic variants: a systematic review. Journal of Parkinson's Disease. 2020. ↩︎
Scarffe LA, Stevens DA, Talbot EL, et al. Parkin and PINK1: much more than mitophagy. Trends in Neurosciences. 2014. ↩︎
Tokarew JM, El-Khodor BF, Murer F, et al. Parkin substrate identification and characterization. Journal of Parkinson's Disease. 2021. ↩︎
Moisoi N, Phadwal K. Therapeutic strategies for PINK1/Parkin-mediated mitophagy. Journal of Parkinson's Disease. 2020. ↩︎