Objective/Rationale:
Mutations in the LRRK2 gene are now recognized as the most common genetic cause of Parkinson’s disease, responsible for not only several inherited forms of this movement disorder, but also contributing to sporadic disease. Evidence suggests that overactive LRRK2 may contribute to disease, therefore it is necessary to understand how LRRK2 is “turned on” and “turned off” in the brain. Recent data implicates the localization of LRRK2 within the cell as a key factor in its level of activity.
Project Description:
To understand how the localization of LRRK2 within the cell is regulated, we will employ a variety of antibody- and drug-based approaches to study how LRRK2 that is attached to the cell membrane differs from the free, cytoplasmic protein. In addition we will use high-resolution mass spectrometry, a technology that allows us to study the LRRK2 protein at the molecular and chemical level, to identify features of the protein that direct it to the membrane, and promotes its activation. We will study LRRK2 that is expressed in cultured cells, as well as LRRK2 extracted from the brains of various pre-clincal models of Parkinson’s disease.
Relevance to Diagnosis/Treatment of Parkinson’s Disease:
Membrane-attachment has been shown to increase LRRK2 activity, and enhanced LRRK2 activity is thought to contribute to the Parkinson’s disease process. Through a better understanding of how LRRK2 binds to membranes and becomes ‘activated’, we may uncover novel mechanisms to “turn off” LRRK2. This work will contribute to a better understanding of LRRK2 function and may lead to the design of novel therapeutic strategies to block or inhibit LRRK2 function in the brain.
Anticipated Outcome:
In this study, we expect to uncover the underlying mechanisms that regulate the distribution of LRRK2 across the cell. This may include post-translational modifications such as phosphorylation or oxidation, or other chemical modifications that govern LRRK2 localization and activity. Our work will emphasize the study of endogenous expression levels of LRRK2, and protein extracted from brain tissue, to examine the most physiologically relevant conditions feasible.