LRRK2 (Leucine-Rich Repeat Kinase 2) mutant dopamine neurons are induced pluripotent stem cell (iPSC)-derived neurons carrying pathogenic mutations in the LRRK2 gene, most commonly the G2019S gain-of-function mutation. These neurons serve as a critical disease model for studying the pathogenesis of late-onset sporadic Parkinson's disease (PD) and testing therapeutic interventions. [@cookson2010]
Overview
LRRK2 Mutations in Parkinson's Disease
Common Pathogenic Mutations
The LRRK2 gene encodes a large multidomain protein with serine/threonine kinase activity. Several pathogenic mutations cause familial and sporadic PD:
LRRK2 (Leucine-Rich Repeat Kinase 2) mutant dopamine neurons are induced pluripotent stem cell (iPSC)-derived neurons carrying pathogenic mutations in the LRRK2 gene, most commonly the G2019S gain-of-function mutation. These neurons serve as a critical disease model for studying the pathogenesis of late-onset sporadic Parkinson's disease (PD) and testing therapeutic interventions. [@cookson2010]
Overview
LRRK2 Mutations in Parkinson's Disease
Common Pathogenic Mutations
The LRRK2 gene encodes a large multidomain protein with serine/threonine kinase activity. Several pathogenic mutations cause familial and sporadic PD:
G2019S: Most common gain-of-function mutation (~5-6% familial PD, ~1-2% sporadic PD)
R1441C/G/H: Affects the ROC GTPase domain
Y1699C: Affects the COR domain
I2020T: Located in the kinase domain
The G2019S mutation increases kinase activity by approximately 2-3 fold, leading to enhanced phosphorylation of LRRK2 substrates including Rab10, Rab8A, and Rab12.
Cellular Phenotypes in LRRK2 Mutant Dopamine Neurons
Mitochondrial Dysfunction
LRRK2 mutant dopamine neurons exhibit several mitochondrial abnormalities:
Reduced mitochondrial membrane potential: Decreased Δψm observed in patient-derived neurons
Impaired mitophagy: Defective clearance of damaged mitochondria