Using the beta-lactamase protein-fragment complementation assay to probe dynamic protein-protein interactions

Area of Science:

• Molecular Biology
• Cell Biology
• Biochemistry

Background:

• Protein-protein interactions are crucial for cellular functions.
• Detecting dynamic interactions in living cells remains challenging.
• Protein-fragment complementation assays (PCAs) offer a sensitive detection method.

Purpose of the Study:

• To present a general strategy for quantitative detection of dynamic protein-protein interactions.
• To describe protocols for a TEM beta-lactamase-based PCA in mammalian cells.
• To enable rapid and sensitive detection of protein interactions.

Main Methods:

• Developed a protein-fragment complementation assay (PCA) using TEM beta-lactamase as a reporter.
• Fused complementary beta-lactamase fragments to proteins of interest.
• Utilized substrates converted to fluorescent or colored products by reconstituted beta-lactamase.

Main Results:

• Demonstrated quantitative detection of dynamic protein-protein interactions in living cells.
• Achieved signal amplification through enzyme reporter activity.
• Developed a protocol completable within hours.

Conclusions:

• The TEM beta-lactamase PCA provides a rapid and sensitive method for studying protein interaction dynamics.
• This assay is valuable for quantitative analysis of protein interactions in real-time.
• The developed protocol facilitates efficient investigation of cellular signaling pathways.