Bacterial beta-lactamase fragmentation complementation strategy can be used as a method for identifying interacting...

Area of Science:

• Biochemistry
• Molecular Biology
• Genetics

Background:

• Protein-protein interactions are crucial for cellular functions.
• Screening methods are needed to identify these interactions efficiently.
• The TEM-1 beta-lactamase fragment complementation (BFC) system offers a potential bacterial screening strategy.

Purpose of the Study:

• To establish and validate a bacterial BFC system for screening protein-protein interactions.
• To identify novel protein interaction partners using this BFC system.
• To investigate the functional consequence of a newly identified protein interaction.

Main Methods:

• Generation of a bacterial BFC system using human Fas-associated death domain (hFADD) and human Fas death domain (hFasDD).
• Verification of interactions via ampicillin resistance, nitrocefin colorimetry, and His pull-down assays.
• Screening of a bacterial BFC cDNA library to identify interacting proteins of human uracil DNA glycosylase (hUNG).
• Confirmation of hUNG-CHCH5 interaction using immunoprecipitation in a mammalian system.

Main Results:

• The hFADD-hFasDD interaction was successfully validated using multiple assays.
• The bacterial BFC cDNA library strategy identified coiled-coil helix coiled-coil domain-containing protein 5 (CHCH5) as a novel interacting protein of hUNG.
• CHCH5 was confirmed to interact with hUNG in a mammalian expression system.
• CHCH5 significantly enhanced the DNA glycosylase activity of hUNG.

Conclusions:

• The bacterial BFC system is a viable and effective strategy for screening protein-protein interactions.
• This method successfully identified a novel interaction between hUNG and CHCH5.
• The identified interaction has functional implications for DNA repair mechanisms.