Measuring Proteasome Activity in Different Subcellular Compartments of the Rat Brain

Source: McFadden, T., et al. Quantifying Subcellular Ubiquitin-proteasome Activity in the Rodent Brain. J. Vis. Exp. (2019). This video demonstrates how to measure proteasome activity in different subcellular compartments of the lateral amygdala from fear-conditioned and control rat brains using a fluorogenic peptide assay. The proteasome cleaves the fluorogenic peptide substrate, releasing fluorescent molecules, which are quantified using a plate reader to assess proteasome activity in the nuclear and synaptic protein fractions. Increased nuclear activity suggests changes in gene expression, while reduced synaptic activity indicates protein stabilization necessary for long-term memory maintenance.