Regulation of LRRK2 activity by metabolic stress and heavy metal exposure

Genetic variability in the gene encoding leucine-rich repeat kinase 2 (LRRK2) is associated with both familial and sporadic Parkinson's disease (PD). While LRRK2 is known to modulate vesicular trafficking and stress signaling through its phosphorylation and kinase activity, how it responds to metabolic and environmental stressors remains poorly understood. Here, we show that acute inhibition of glycolysis and oxidative phosphorylation triggers rapid, reversible dephosphorylation of LRRK2 at constitutive sites in cells, ex vivo brain slices, and primary astrocytes. In contrast, glucose deprivation modestly increases LRRK2 kinase activity and Rab substrate phosphorylation. In vivo, chronic 2-deoxyglucose treatment reduces S935 phosphorylation in kidney tissue, linking energy stress to LRRK2 modulation in peripheral organs. Strikingly, manganese (Mn), a PD-relevant environmental toxicant, robustly activates LRRK2, inducing pS1292 autophosphorylation and phosphorylation of Rab8a, Rab10 and Rab12, while suppressing S935 phosphorylation after a 24 hrs exposure. Time-resolved analysis revealed distinct temporal substrate regulation, with rapid Rab12 phosphorylation and pRab10 levels gradually increasing and peaking only after 24 h. Phosphorylated Rab10 remains closely associated with both lysosomal and centrosomal membranes under Mn stress. Mn impaired mitochondrial respiration and increased ROS, and antioxidant treatment rescued Rab10 phosphorylation, establishing a redox-dependent mechanism of LRRK2 activation. Together, these findings reveal stressor-specific modes of LRRK2 regulation and suggest that LRRK2 integrates metabolic and environmental signals via redox-sensitive pathways relevant to PD pathogenesis.