The structure of LRRK2 and the conformational changes that are associated with LRRK2 activation and Parkinson’s disease pathogenesis

Abstract

Parkinson’s Disease (PD), a major neurodegenerative disorder, is characterized by chronic and progressive loss of dopaminergic neurons ultimately leading to death. Leucine‐rich repeat kinase 2 (LRRK2) is one of the greatest known genetic contributors to PD. LRRK2 is a large multi‐domain protein that contains a kinase domain as well as a Ras/GTPase (ROC) domain, followed by a COR domain. LRRK2 also acts as scaffold for the assembly of signaling complexes with its armadillo, ankyrin, leucine‐rich and WD40 domains at the N‐ and C‐termini. Studies have shown that most of the common familial mutations resulted in the formation of fibrous structures docked on microtubules in cells. However, how the fibrous structure is associated with LRRK2 activation is still unclear. Little is known about how LRRK2 activity is regulated, as well as the pathogenic mechanisms that drive PD. In this study, we use hydrogen‐deuterium exchange mass spectrometry (HDX‐MS) to measure the solvent exposed regions of LRRK2. Purified truncated LRRK2 (RCKW), which includes ROC, COR, kinase and WD40 domain, was used to map conformational changes associated with ATP, GTP and kinase inhibitor binding. Mutations in the kinase domain, including two familial mutations (G2019S and I2020T), are characterized as well. This information will help us to understand the protein interfaces within and between LRRK2 oligomers involved in LRRK2 activity. Also, it will help to understand the conformation that drives the activation of LRRK2 and pathological docking onto microtubules.