Role of LRRK2 in axonal transport and Parkinson's disease

Axonal transport is crucial for neuronal health and function, facilitating the delivery of newly synthesized material from the soma via anterograde transport and the removal of aged proteins and damaged organelles for degradation via retrograde transport. Emerging evidence links Parkinson's disease (PD)-causing mutations in the leucine-rich repeat kinase 2 (LRRK2) gene to dysfunctional axonal transport. Pathogenic LRRK2 mutations induce increased LRRK2 kinase activity, leading to the hyperphosphorylation of RAB proteins, which are key regulators of intracellular trafficking and transport. Here, we review the current literature on how LRRK2 affects the axonal transport of different cargoes, focusing on synaptic vesicle precursors, mitochondria, and autophagosomes. We further discuss how LRRK2 influences cytoskeletal dynamics and how it affects vesicle trafficking at the Golgi, which may indirectly contribute to its effect on axonal transport. This review summarizes our current understanding of how pathogenic LRRK2 hyperactivation disrupts axonal transport and how this may be linked to the neurodegeneration of PD.