MG-132 is a potent proteasome inhibitor widely used in research to study protein degradation pathways. It effectively blocks the activity of the 26S proteasome, preventing the breakdown of ubiquitinated proteins, which allows scientists to investigate the role of protein turnover in cellular processes. It is commonly applied in studies of apoptosis, cell cycle regulation, inflammation, and signal transduction pathways such as NF-κB activation. Due to its ability to stabilize regulatory proteins, MG-132 is used to induce stress responses in cells and to examine the accumulation of misfolded proteins, making it a valuable tool in cancer research and neurodegenerative disease studies. Its reversible inhibition mechanism also allows for controlled experiments where temporary proteasome suppression is needed.