Identification of Ku70 Domain-Specific Interactors Using BioID2.

Area of Science:

• Biochemistry
• Molecular Biology
• Proteomics

Background:

• Proximity-dependent biotin identification (BioID) is an in vivo method for identifying protein interactors.
• BioID has undergone significant advancements, with new variants regularly expanding its capabilities.
• The full potential of existing BioID variants for studying protein interactions remains underexplored.

Purpose of the Study:

• To innovatively apply BioID2 to identify and map domain-specific protein interactions of human Ku70.
• To investigate protein interactions with specific regions of Ku70, particularly the N-terminal von Willebrand A-like (vWA) domain.
• To evaluate the advantages and limitations of the BioID2 technique in this context.

Main Methods:

• Development of four HEK293 cell lines stably expressing different BioID2-tagged Ku70 segments.
• Utilizing a segmented approach to target protein interactions with distinct Ku70 regions.
• Employing BioID2 for in vivo biochemical screening of proximal protein interactors.

Main Results:

• Identification of domain-specific protein interactors for human Ku70.
• Discovery of several potential novel Ku70 interactors.
• Validation of RNF113A and Spindly as proteins interacting with the Ku70 vWA domain.

Conclusions:

• The BioID2 technique can be effectively used in a segmented manner to map domain-specific protein interactions.
• This approach successfully identified novel interactors for the Ku70 protein, particularly for its N-terminal vWA domain.
• The study highlights RNF113A and Spindly as key proteins interacting with the Ku70 vWA domain.