Application of the Fluorescence Resonance Energy Transfer Method for Studying the Dynamics of Caspase-3 Activation during UV-Induced Apoptosis in Living HeLa Cells

Authors: Luo K.Q.; Yu V.C.; Pu Y.; Chang D.C.

Source: Biochemical and Biophysical Research Communications, Volume 283, Number 5, May 2001 , pp. 1054-1060(7)

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Abstract:

Activation of caspase-3 is a central event in apoptosis. We have developed a GFP-based FRET (fluorescence resonance energy transfer) probe that is highly sensitive to the activation of caspase-3 in intact living cells. This probe was constructed by fusing a CFP (cyan fluorescent protein) and a YFP (yellow fluorescent protein) with a specialized linker containing the caspase-3 cleavage sequence: DEVD. The linker design was optimized to produce a large FRET effect. Using purified protein, we observed a fivefold change in the fluorescence emission ratio when the probe was cleaved by caspase-3. To demonstrate the usefulness of this method, we introduced this FRET probe into HeLa cells by both transient and stable transfection. We observed that during UV-induced apoptosis, the activation of caspase-3 varied significantly between different cells; but once the caspase was activated, the enzyme within the cell became fully active within a few minutes. This technique will be highly useful for correlating the caspase-3 activation with other apoptotic events and for rapid-screening of potential drugs that may target the apoptotic process. Copyright 2001 Academic Press.

Keywords: FRET; GFP; apoptosis; caspase

Language: English

Document Type: Research article

Affiliations: Department of Biology, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China

Publication date: 2001-05-01