A novel quenched fluorescent activity-based probe reveals caspase-3 activity in the endoplasmic reticulum during apoptosis

作者：Shaulov Rotem Yulia; Merquiol Emmanuelle; Weiss Sadan Tommy; Moshel Ofra; Salpeter Seth; Shabat Doron; Kaschani Farnusch; Kaiser Markus; Blum Galia^*

来源：Chemical Science, 2016, 7(2): 1322-1337.

DOI：10.1039/c5sc03207e

The caspases are a family of cysteine proteases that are key regulators of apoptosis and their activity may thus serve as a good marker to monitor cell death. We have developed a quenched fluorescent activity-based probe (qABP) that is selective for caspase-3 activity and emits a fluorescent signal after covalently modifying its target. The probe has a wide range of potential applications, e.g. in real-time imaging, FACS analysis or biochemical quantification of caspase activity in intact cells. Application of the probe allowed us to monitor caspase-3 activation after chemotherapy-treatment and to distinguish between apoptosis sensitive and resistant cells. Moreover, it enabled real-time high-resolution visualization of active caspase-3 during apoptosis. This led to the surprising finding that in cancerous cells active caspase-3 is not only found at the familiar cellular locations but also in mitochondria and the endoplasmic reticulum. Thus, our novel covalent probe allows high spatial and temporal resolution imaging of caspase-3 activation and may thus be used as an effective tool to study molecular mechanisms of programmed cell death in healthy and disease states.

• 出版日期2016