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Updated: Apr 20, 2026
Spatio-Temporal Manipulation of Small GTPase Activity at Subcellular Level and on Timescale of Seconds in Living Cells
Published on: March 9, 2012
LRRK2 localizes to endosomes and interacts with clathrin-light chains to limit Rac1 activation
Andrea M A Schreij1, Mathilde Chaineau1, Wenjing Ruan1
1Department of Neurology and Neurosurgery and McGill Parkinson Program, Montreal Neurological Institute McGill University, Montreal, Quebec, Canada.
Abstract:
Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common cause of dominant-inherited Parkinson's disease (PD), and yet we do not fully understand the physiological function(s) of LRRK2. Various components of the clathrin machinery have been recently found mutated in familial forms of PD. Here, we provide molecular insight into the association of LRRK2 with the clathrin machinery. We report that through its GTPase domain, LRRK2 binds directly to clathrin-light chains (CLCs). Using genome-edited HA-LRRK2 cells, we localize LRRK2 to endosomes on the degradative pathway, where it partially co-localizes with CLCs. Knockdown of CLCs and/or LRRK2 enhances the activation of the small GTPase Rac1, leading to alterations in cell morphology, including the disruption of neuronal dendritic spines. In Drosphila, a minimal rough eye phenotype caused by overexpression of Rac1, is dramatically enhanced by loss of function of CLC and LRRK2 homologues, confirming the importance of this pathway in vivo. Our data identify a new pathway in which CLCs function with LRRK2 to control Rac1 activation on endosomes, providing a new link between the clathrin machinery, the cytoskeleton and PD.
Insights
Leucine-rich repeat kinase 2 (LRRK2) interacts with clathrin-light chains (CLCs) on endosomes. This interaction regulates Rac1 activation, offering new insights into Parkinson's disease (PD) pathogenesis and the clathrin machinery.
Area of Science:
- Cell Biology
- Neuroscience
- Molecular Biology
Background:
- Mutations in leucine-rich repeat kinase 2 (LRRK2) are a leading cause of inherited Parkinson's disease (PD).
- The physiological functions of LRRK2 remain incompletely understood.
- Components of the clathrin machinery are implicated in familial PD.
Purpose of the Study:
- To elucidate the molecular association between LRRK2 and the clathrin machinery.
- To investigate the role of LRRK2 and clathrin-light chains (CLCs) in cellular pathways relevant to PD.
Main Methods:
- Direct binding assays to demonstrate LRRK2-CLC interaction via the LRRK2 GTPase domain.
- Localization studies in genome-edited cells to pinpoint LRRK2 and CLC co-localization on endosomes.
- Gene knockdown experiments to assess the impact on Rac1 activation and cell morphology.
- In vivo validation using Drosophila models.
Main Results:
- LRRK2 directly binds to CLCs through its GTPase domain.
- LRRK2 localizes to endosomes and partially co-localizes with CLCs.
- Knockdown of CLCs or LRRK2 leads to enhanced Rac1 activation and altered cell morphology, including disrupted dendritic spines.
- Drosophila models confirm the in vivo significance of the LRRK2-CLC-Rac1 pathway.
Conclusions:
- A novel pathway is identified where CLCs and LRRK2 collaborate to control Rac1 activation on endosomes.
- This study establishes a new connection between the clathrin machinery, cytoskeleton regulation, and Parkinson's disease.
- Findings provide molecular insights into LRRK2 function and its role in PD pathogenesis.
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