Bidirectional genome-wide CRISPRi/a screening using ratiometric GCase substrates to identify genetic modulators of lysosomal GCase activity

Parkinson’s disease (PD) is a progressive brain disorder in which lysosomes—the cell’s waste-clearing system—do not function properly, leading to toxic buildup that harms neurons. The enzyme glucocerebrosidase (GCase), encoded by GBA1 gene, breaks down glycolipid molecules that have essential roles in neurons. Mutations in GBA1 gene reduce GCase activity, causing toxic glycolipid accumulation and increasing PD risk. However, not everyone with these mutations develops PD, suggesting the existence of other genes that may modify GCase function. Only a very small set of modifiers has been found. Thus, there are likely several other genes that impact GCase activity.
In my proposed project, I will use a cutting-edge technology, CRISPR screening, to test which genes influence GCase activity within neurons. By identifying genes that increase or decrease lysosomal GCase activity, we aim to map the genetic network regulating GCase in brain cells. Understanding this network will reveal how GCase contributes to development and progression of PD and may uncover new targets that could be targeted for therapeutic benefit. Ultimately, this work may guide the creation of treatments that slow or halt PD and improve diagnostic strategies.