Visualization of caspase-3-like activity in cells using a genetically encoded fluorescent biosensor activated by protein cleavage.

TitleVisualization of caspase-3-like activity in cells using a genetically encoded fluorescent biosensor activated by protein cleavage.
Publication TypeJournal Article
Year of Publication2013
AuthorsZhang J, Wang X, Cui W, Wang W, Zhang H, Liu L, Zhang Z, Li Z, Ying G, Zhang N, Li B
JournalNature communications
Volume4
Pagination2157
Date Published2013
Abstract

Cytosolic caspase-3-like proteases, such as caspase-3 and caspase-7, have a central role in mediating the progress of apoptosis. Here to conveniently monitor caspase-3-like activity in the multicellular environment, we have developed genetically encoded switch-on fluorescence-base indicators that are cyclized chimeras containing a caspase-3 cleavage site as a switch. When cleaved by caspase-3-like proteases, the non-fluorescent indicator rapidly becomes fluorescent, and thus detects in real-time the activation of such caspases. We generate cultured cells constitutively expressing these chimeras, and all the healthy cells are non-fluorescent. When these cells are exposed to apoptotic stimuli, dead cells show strong fluorescence depending on caspase activation. With these tools, we monitor in real-time caspase-3-like activity in each cell under various conditions, and show for the first time that the environment of cancer cells affects their sensitivity to chemotherapeutic drugs in a modified soft agar assay. These biosensors should enable better understanding of the biological relevance of caspase-3-like proteases.

DOI10.1093/ajh/hpt119
Alternate JournalNat Commun