Objective/Rationale:
Mutations in the Leucine Rich Repeat Kinase 2 (LRRK2) gene are associated with Parkinson’s disease (PD). Although the biological function of LRRK2 is not known, inhibitors of LRRK2 kinase activity could potentially be used to prevent or treat PD. Identifying and developing these kinase inhibitors is difficult, but can be greatly facilitated by knowing the three dimensional structure of LRRK2. The goal of this project is to obtain the first three dimensional structure of LRRK2 kinase.
Project Description:
Because of the fundamental importance of LRRK2 in Parkinson’s disease, a large number of academic and industrial laboratories have attempted to obtain a crystal structure of the kinase domain of LRRK2; however, no three dimensional structure has been described. The purpose of this consortium is to bring together multiple laboratories, technologies and approaches to obtain the first LRRK2 crystal structure. By bringing together both academic and industrial leaders, we will have a unique approach to solve this difficult problem. The consortia will also benefit by being part of the larger LRRK2 biology consortia already established by MJFF, and we will be working closely with this group to apply the latest results and technologies.
Relevance to Diagnosis/Treatment of Parkinson’s Disease:
Mutations in the LRRK2 protein associated with Parkinson’s disease may increase the kinase activity of this enzyme. If this is true, inhibitors of LRRK2 could be used to treat or prevent PD. Identifying and developing small molecules that inhibit LRRK2 but not other essential kinases is difficult. Other therapeutic kinases inhibitors (e.g. Gleevec) have been enabled by structure guided design. We hope to enable the discovery and development of PD therapeutics by obtaining the first LRRK2 kinase crystal structure.
Anticipated Outcome:
We hope to identify methods for expressing large quantities of active LRRK2. This information will be beneficial for the PD community working to understand the biochemistry of LRRK2. We hope to identify molecules that interact and stabilize LRRK2. This will be beneficial for the PD community working to understand the biological function of LRRK2. Finally, we hope to obtain the first X-ray crystal structure of LRRK2 kinase to enable drug discovery and development.
Progress Report
LRRK2 is a large complex protein that has been difficult to obtain in sufficient quantities to study biochemically. We have developed new systems for making this protein in cells in the laboratory, and have also created new protocols for purifying sufficient quantities of the protein for structural studies. We are currently using this protein in cryo-electron microscopy (cryo-EM) experiments to generate 3-dimensional pictures of what the protein looks like. We have used this protein to create chemically modified DNA molecules (called “SOMAmers”) that specifically bind the LRRK2 protein and inhibit its activity. We are currently using these to map the known functional domains of the LRRK2 protein onto the 3-dimensional pictures of LRRK2. By doing this we hope to understand how mutations in LRRK2 that are associated with Parkinson’s disease disrupt the normal structure and function of LRRK2.
June 2014