Rationally designed fluorogenic protease reporter visualizes spatiotemporal dynamics of apoptosis in vivo

Area of Science:

• Biotechnology
• Molecular Imaging
• Cell Biology

Background:

• Fluorescence resonance energy transfer (FRET)-based reporters are limited in vivo due to poor signal.
• Fluorogenic reporters offer improved signal but lack protease-specific in vivo imaging tools.

Purpose of the Study:

• To engineer a novel infrared fluorogenic protease reporter for enhanced in vivo imaging.
• To demonstrate the utility of this reporter in visualizing protease activity and apoptosis in biological systems.

Main Methods:

• Redesign of an infrared fluorescent protein for protease-regulated chromophore incorporation.
• Development of an infrared fluorogenic executioner-caspase reporter.
• Application in Drosophila models to study apoptosis during embryogenesis and tumorigenesis.

Main Results:

• The engineered reporter becomes fluorescent upon protease activation without exogenous cofactors.
• Successfully visualized spatiotemporal coordination of apoptosis and embryonic morphogenesis in Drosophila.
• Revealed dynamics of apoptosis during tumorigenesis in Drosophila.

Conclusions:

• The developed infrared fluorogenic protease reporter enables sensitive in vivo imaging of protease activity.
• This technology provides new insights into apoptosis dynamics in developmental and disease contexts.
• The reporter scaffold can be adapted to create reporters for various proteases.