Abstract
Mutations in LRRK2 are a common cause of genetic Parkinson’s disease (PD). LRRK2 is a multi-domain Roco protein, harbouring kinase and GTPase activity. In analogy with a bacterial homologue, LRRK2 was proposed to act as a GTPase activated by dimerization (GAD), while recent reports suggest LRRK2 to exist under a monomeric and dimeric form in vivo. It is however unknown how LRRK2 oligomerization is regulated. Here, we show that oligomerization of a homologous bacterial Roco protein depends on the nucleotide load. The protein is mainly dimeric in the nucleotide-free and GDP-bound states, while it forms monomers upon GTP binding, leading to a monomer-dimer cycle during GTP hydrolysis. An analogue of a PD-associated mutation stabilizes the dimer and decreases the GTPase activity. This work thus provides insights into the conformational cycle of Roco proteins and suggests a link between oligomerization and disease-associated mutations in LRRK2.
Highlights
Mutations in leucine-rich-repeat kinase 2 (LRRK2) are a common cause of genetic Parkinson’s disease (PD)
Using small angle X-ray scattering (SAXS), multi-angle light scattering (MALS), native mass spectrometry (MS), analytical ultracentrifugation (AUC) and electron microscopy (EM), we demonstrate that the C. tepidum Roco protein is mainly dimeric in the nucleotide-free and GDP-bound states, while it is mainly monomeric when bound to GTP
To investigate the influence of nucleotide binding on the conformation of CtRoc-COR we set out to perform small angle X-ray scattering coupled to size-exclusion chromatography (SEC-SAXS) experiments with the protein in either the nucleotide-free state or saturated with GDP or the GTP mimic 5′-guanylyl imidodiphosphate (GppNHp) (Supplementary Fig. 2)
Summary
Mutations in LRRK2 are a common cause of genetic Parkinson’s disease (PD). LRRK2 is a multi-domain Roco protein, harbouring kinase and GTPase activity. The model that LRRK2 functions as a GAD (G protein activated by nucleotide-dependent dimerization) is heavily based on the crystal structure of the dimeric Roc-COR module of the Roco protein from Chlorobium tepidum[14, 17, 18]. A mutation linked to PD decreases the GTPase activity by interfering with the monomer-dimer equilibrium Together these results shed new light on a long-standing discussion regarding the oligomeric state of Roco proteins, and propose a model for their GTP hydrolysis mechanism
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
