A Unique Genetically Encoded FRET Pair in Mammalian Cells

Area of Science:

• Biochemistry
• Molecular Biology
• Biophysics

Background:

• Förster resonance energy transfer (FRET) is crucial for studying dynamic protein structural changes in vitro and in vivo.
• Genetically encoded FRET pairs offer a labeling-free method for protein investigation.
• Current genetically encoded FRET pairs in mammalian cells utilize fluorescent proteins, which can be large and cause perturbations, limiting their application.

Purpose of the Study:

• To develop a novel, genetically encoded FRET pair for mammalian cells that overcomes the limitations of existing fluorescent protein-based systems.
• To create a versatile FRET tool with improved applicability for monitoring protein structure dynamics.

Main Methods:

• Development of a FRET pair utilizing a small, genetically encoded fluorescent unnatural amino acid (as donor) and enhanced green fluorescent protein (EGFP) (as acceptor).
• Co-translational incorporation of the unnatural amino acid into internal sites of target proteins.
• Utilizing the FRET pair in mammalian cells for monitoring protein dynamics.

Main Results:

• Successfully developed and demonstrated a novel genetically encoded FRET pair in mammalian cells.
• The new FRET pair leverages a small unnatural amino acid donor and EGFP acceptor.
• This system allows for internal protein labeling, offering greater versatility compared to terminal labeling with fluorescent proteins.

Conclusions:

• The developed FRET pair, using a small unnatural amino acid and EGFP, provides a versatile alternative to fluorescent protein-based FRET systems.
• Its small size and ability for internal incorporation minimize protein perturbations and enhance applicability in studying protein structure dynamics.
• This innovative FRET strategy expands the toolkit for molecular biology and biophysics research in mammalian systems.