Leucine-Rich Repeat Kinase 2: Pathways to Parkinson's Disease

The past 10 years have seen tremendous progress in our understanding of leucine-rich repeat kinase 2 (LRRK2) and how mutations activate the kinase and trigger downstream pathology, contributing to Parkinson's disease. A breakthrough came from the identification of key LRRK2 substrates-a subset of small guanosine triphosphatases (GTPases) called Rab proteins. Cryoelectron microscopy has revealed structures of LRRK2 and showed how inhibitors engage and inhibit the kinase. Biochemical experiments have revealed how LRRK2 is recruited to membranes to phosphorylate Rab substrates. LRRK2 activation during lysosomal stress triggers Rab phosphorylation, altering the repertoire of Rab-binding partners. Resulting phospho-Rab-effector complexes have prominent effects in specific cell types, disrupting primary cilia and impairing Hedgehog signaling-effects that can be reversed by LRRK2 inhibitors. This disruption in Hedgehog signaling represents a convergence point linking genetic and idiopathic forms of Parkinson's. Together, these findings support the therapeutic potential of LRRK2 inhibitors in Parkinson's disease.