# Genetically encoded and modular subcellular organelle probes reveal dysfunction in lysosomes and mitochondria driven by PRKN knockout

## TL;DR

Researchers created a new tool called GEM-SCOPe to study how lysosomes and mitochondria malfunction in a Parkinson's disease model using human cells.

## Contribution

GEM-SCOPe is a novel, modular fluorescent toolbox for live-cell imaging of subcellular organelles in disease models.

## Key findings

- PRKN knockout astrocytes show mitochondrial transport and turnover issues.
- Lysosomal distribution and reactive oxygen species levels are altered in PRKN−/− cells.
- GEM-SCOPe reveals proliferation dysfunction linked to Parkinson's disease mechanisms.

## Abstract

Cellular processes including lysosomal and mitochondrial dysfunction are implicated in the development of many diseases. Quantitative visualization of mitochondria and lysosomes is crucial to understand how these organelles are dysregulated during disease. To address a gap in live-imaging tools, we developed GEM-SCOPe (genetically encoded and modular subcellular organelle probes), a modular toolbox of fluorescent markers designed to inform on localization, distribution, turnover, and oxidative stress of specific organelles. We expressed GEM-SCOPe in differentiated astrocytes and neurons from a human pluripotent stem cell PRKN-knockout model of Parkinson’s disease and identified disease-associated changes in proliferation, lysosomal distribution, mitochondrial transport and turnover, and reactive oxygen species. We demonstrate GEM-SCOPe is a powerful panel that provides critical insight into the subcellular mechanisms underlying Parkinson’s disease in human cells. GEM-SCOPe can be expanded upon and applied to a diversity of cellular models to glean an understanding of the mechanisms that promote disease onset and progression.

•We designed a modular set of lentiviral fluorescent reporters for live-cell imaging•GEM-SCOPe captures subcellular effects of chemical or genetic perturbations•PRKN−/− astrocytes exhibit mitochondrial, lysosomal, and proliferation dysfunction

We designed a modular set of lentiviral fluorescent reporters for live-cell imaging

GEM-SCOPe captures subcellular effects of chemical or genetic perturbations

PRKN−/− astrocytes exhibit mitochondrial, lysosomal, and proliferation dysfunction

Molecular biology; Cell biology