A novel quenched fluorescent activity-based probe reveals caspase-3 activity in the endoplasmic reticulum during apoptosis. Issue 2 (24th November 2015)

• Record Type: Journal Article
• Authors: Shaulov-Rotem, Yulia; Merquiol, Emmanuelle; Weiss-Sadan, Tommy; Moshel, Ofra; Salpeter, Seth; Shabat, Doron; Kaschani, Farnusch; Kaiser, Markus; Blum, Galia
• Is Part Of: Chemical science. Volume 7:Issue 2(2016:Feb.)
• Page Start: 1322
• Page End: 1337
• Publication Date: 2015-11-24
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5sc03207e
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : A selective quenched activity-based probe detects caspase-3 activity in the endoplasmic reticulum of cancerous cells during apoptosis. Abstract : 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.