Meet a Researcher Investigating a Missing Link Between Genetic Mutation and Protein Clumping in PD

After decades of research, several genetic mutations have been linked to Parkinson’s disease (PD) but we do not fully understand how these mutations cause PD. 

One such PD-associated mutation leads to the production of a malfunctioning version of the protein Leucine Rich Repeat Kinase 2 (LRRK2). Faulty LRRK2 is believed to disrupt several important processes within neurons and consequently contribute to PD progression, but how exactly these disruptions lead to the disease is still being studied. 

When looking at the posthumous brain tissue of people who had LRRK2-mutant PD, scientists have routinely seen unhealthy aggregates or clumps of a protein called tau. Similar to alpha-synuclein clumping, tau clumping is believed to contribute to the disease-related breakdown of dopamine neurons and is associated with PD dementia.   

Silas Buck, PhD, recipient of a Parkinson’s Foundation Postdoctoral Fellowship, is investigating how a relatively understudied protein called Histone Deacetylase 6 (HDAC6), which is responsible for regulating tau and keeping it from clumping, may be affected by mutant LRRK2 and drive PD-related cellular breakdown.  

“What I’m studying is how LRRK2 may cause the accumulation of a protein called tau. When tau is misfolded, it can accumulate into these clumps in the brain cells and that can cause neurons, or brain cells, to degenerate and lead to not just movement symptoms, but tau, specifically, is also associated with the cognitive symptoms that are seen in Parkinson’s. So, addressing the cause of tau protein accumulation can potentially treat non-movement symptoms in people with PD,” said Dr. Buck. 

Using neurons grown in petri dishes, Dr. Buck will first measure how much LRRK2 and HDAC6 interact in healthy brain cells.   

Then, he will introduce mutant LRRK2 into those cells and analyze how that affects the LRRK2-HDAC6 interactions and if such changes result in tau clumping. Finally, Dr. Buck will investigate if mutant LRRK2’s impact on HDAC6 also contributes to disrupted mitochondria repair and cleanup, another cellular stressor commonly seen in PD brain tissue.   

Uncovering more biochemical links in the chain between gene mutation and PD means more opportunities to intervene in the disease’s progression. Through Dr. Buck’s experiments, we will understand more about HDAC6’s role in PD development and how it could be the target of new future therapies, expanding the effective medication options and improving doctors’ ability to provide genetically personalized treatment plans for people with Parkinson’s. 

“Studying these proteins and how they are dysfunctional in Parkinson’s disease can inform us not just about those genetic cases but also how Parkinson’s disease forms in cases that do not have a clear genetic form as well,” Dr. Buck said. 

“This fellowship from the Parkinson’s Foundation is key to helping me develop into a fully independent scientist and investigator, where I can one day have my own research program and run my own lab to continue investigating mechanisms of degeneration in Parkinson’s disease,” Dr. Buck said. “Receiving this postdoctoral fellowship allows me to pursue my passion of performing exciting and important research that could one day help substantially improve the lives of people with Parkinson’s disease. It has always been my dream to make a difference in the health of others through research, and I hope to achieve that through this project.”  

Meet more Parkinson’s researchers! Explore our My PD Stories featuring PD researchers.