Development of Fluorogenic Probes for Rapid High-Contrast Imaging of Transient Nuclear Localization of Sirtuin 3

Area of Science:

• Biochemistry
• Chemical Biology
• Molecular Imaging

Background:

• Protein labeling is crucial for visualizing cellular components.
• Existing methods often lack speed and contrast for live-cell imaging.
• The photoactive yellow protein (PYP)-tag system offers a specific labeling target.

Purpose of the Study:

• To develop novel, efficient fluorogenic probes for live-cell protein labeling using the PYP-tag.
• To enhance probe performance by modulating coumarin ligand properties.
• To demonstrate the probe's utility in studying protein localization, such as sirtuin 3.

Main Methods:

• Design and synthesis of coumarin-based fluorogenic probes.
• Incorporation of a hydroxy group to tune spectroscopic properties and reaction rates.
• Live-cell imaging experiments utilizing the PYP-tag system.
• Investigation of sirtuin 3 localization in mitochondria and nucleus.

Main Results:

• The new probes exhibit increased labeling reaction rate constants and fluorescence OFF-ON ratios compared to previous probes.
• Rapid, high-contrast fluorogenic labeling of intracellular proteins was achieved within minutes.
• The probe successfully captured transient nuclear localization of sirtuin 3, resolving previous controversies.

Conclusions:

• The developed coumarin-based fluorogenic probes represent a significant advancement in live-cell protein imaging.
• These probes offer superior performance for rapid and high-contrast labeling of PYP-tagged proteins.
• The technology facilitates dynamic biological process studies, exemplified by clarifying sirtuin 3 localization patterns.