Structural, Post-translational Modification and Small Chemical Approaches to Understand LRRK2 Function in PD
MJFF Research Grant, 2011
This grant builds upon the research from a prior grant:
- Structural and Chemical Approaches to Understand and Modulate LRRK2 Kinase Activity in Parkinson's Disease
Promising Outcomes of Original Grant:
Our original goal was to (1) establish electron microscopy (EM)-based dimeric structural assays for the LRRK2 protein and (2) develop high-throughput kinase assays and screen for small chemical inhibitors of LRRK2 kinase activity (including the FDA-approved library). Our study has achieved the main goals in establishing an EM map of LRRK2 protein that serves as a structural framework to understand LRRK2 activity regulation. In addition, we have performed screening of two chemical libraries (>25,000) and identified 4 compounds (in the sub-micromolar range) as potential LRRK2 kinase inhibitors (FDA-approved compounds). These inhibitors are now being evaluated in cell-based assays and various LRRK2 pre-clinical models.
Objectives for Supplemental Investigation:
The structure-function relationship of LRRK2 kinase is poorly understood. Uncertainty of what constitutes brain-specific LRRK2 complexes (i.e., what type of post-translational modifications and adaptor proteins modulate the activity of pathogenic LRRK2 complexes) and a lack of structural information on these complexes impede progress in the understanding of LRRK2; this in turn impedes development of effective therapeutic strategies for Parkinson's disease. The goal of our current application is to expand on the original project by performing three-dimensional reconstruction of brain LRRK2 protein complexes by electron cryo-microscopy (cryo-EM, as well as determining the effect of brain-specific post-translational modifications (including phosphorylations and other types of potential modifications) and adaptor protein binding in modulating dimeric LRRK2 structure and kinase/GTPase activity.
Importance of This Research for the Development of a New PD Therapy:
We anticipate these studies will lead to (I) an improved resolution of our current structure of LRRK2, and (II) insight into the composition and chemical modifications in brain-specific LRRK2 that modulate structure and enzymatic activity of LRRK2. These results are expected to provide enhanced structural information to evaluate small chemicals of LRRK2 inhibitors in regulating LRRK2 kinase/GTPase activity and better understand their potential in the development of drugs to treat Parkinsonís disease.
Professor of Neurology and Neuroscience, Director of Basic and Translational Research of Movement Disorders at Icahn School of Medicine at Mount Sinai
Location: New York, New York, United States