Zhang, Q., Schepis, A., Huang, H., Yang, J., Ma, W., Torra, J., Zhang, S.Q., Yang, L., Wu, H., Nonell, S., Dong, Z., Kornberg, T.B., Coughlin, S.R., Shu, X. (2019). Designing a Green Fluorogenic Protease Reporter by Flipping a Beta Strand of GFP for Imaging Apoptosis in Animals.  J. Am. Chem. Soc. 141(11): 4526--4530.

FBrf0241847

Research paper

A family of proteases called caspases mediate apoptosis signaling in animals. We report a GFP-based fluorogenic protease reporter, dubbed "FlipGFP", by flipping a beta strand of the GFP. Upon protease activation and cleavage, the beta strand is restored, leading to reconstitution of the GFP and fluorescence. FlipGFP-based TEV protease reporter achieves 100-fold fluorescence change. A FlipGFP-based executioner caspase reporter visualized apoptosis in live zebrafish embryos with spatiotemporal resolution. FlipGFP also visualized apoptotic cells in the midgut of Drosophila. Thus, the FlipGFP-based caspase reporter will be useful for monitoring apoptosis during animal development and for designing reporters of proteases beyond caspases. The design strategy can be further applied to a red fluorescent protein for engineering a red fluorogenic protease reporter.

PMC6486793 (PMC) (EuropePMC)