Leucine-rich repeat kinase 2 (LRRK2) is a ubiquitously expressed member of the ROCO protein family. LRRK2 is a complex, multidomain protein containing kinase and GTPase enzymatic activities and multiple protein-protein interaction domains. LRRK2 is the genetic cause of both familial and idiopathic Parkinson's disease (PD), and it is associated with neuronal death, vesicle trafficking, mitochondrial dysfunction, and inflammation.
LRRK2 is a very large protein comprised of 2527 amino acids which has been determined to contain multiple functional domains, including armadillo (ARM), ankyrin-repeats (ANK), leucine-rich repeats (LRR), Ras of complex proteins (ROC), C-terminal of Roc (COR), MAPK-like kinase, and WD40 motifs. Mutations in LRRK2 represent a significant component of both sporadic and familial PD. Pathogenic mutations cluster in the enzymatic domains of LRRK2, and kinase activity seems to correlate with cytotoxicity, suggesting the possibility of kinase-based therapeutic strategies for LRRK2-associated PD. The best-characterized mutation to date, G2019S, leads to increased kinase activity, and mutations in the GTPase domain, such as R1441C and R1441G, have also been reported to influence kinase activity.