Three-Fragment Fluorescence Complementation for Imaging of Ternary Complexes under Physiological Conditions

Area of Science:

• Molecular Biology
• Cell Biology
• Biochemistry

Background:

• Protein-protein interactions (PPIs) are crucial for cellular processes.
• Identifying multiprotein complexes, especially ternary complexes, in living cells under physiological conditions is challenging.
• Understanding PPIs is key to analyzing biological pathways and molecular mechanisms.

Purpose of the Study:

• To develop a novel method for visualizing and identifying ternary protein complexes in living cells.
• To apply this method to study complex biological processes like HIV-1 integration.

Main Methods:

• Developed a three-fragment fluorescence complementation (TFFC) system using a split Venus fluorescent protein.
• Applied the TFFC system to visualize weak-affinity ternary complexes in living cells.
• Utilized the TFFC system to analyze multi-interactions during HIV-1 integration.

Main Results:

• Successfully visualized ternary complexes in living cells under physiological conditions.
• Identified multi-interactions involving weak-affinity ternary complexes.
• Revealed the role of the barrier-to-autointegration factor protein in HIV-1 integration.

Conclusions:

• The Venus-based TFFC system is an effective tool for visualizing and identifying ternary complexes in living cells.
• This TFFC system advances the study of complex molecular interactions and biological pathways.
• The TFFC system provides new insights into the mechanism of HIV-1 integration.