Light-activated BioID - an optically activated proximity labeling system to study protein-protein interactions

Area of Science:

• Molecular Biology
• Cell Biology
• Biochemistry

Background:

• Proximity labeling is crucial for studying protein-protein interactions within cells.
• Current methods lack precise control over the enzymatic labeling process, limiting accuracy.
• Developing controllable proximity labeling techniques is essential for precise biological studies.

Purpose of the Study:

• To introduce a novel light-activated proximity labeling technology for mapping protein-protein interactions.
• To enhance the accuracy and precision of proximity labeling, particularly at the cell membrane.
• To provide a controllable alternative to existing proximity labeling methods.

Main Methods:

• Developed light-activated BioID (LAB) by fusing split-TurboID enzyme halves to photodimeric proteins CRY2 and CIB1.
• Utilized blue light to induce CRY2-CIB1 dimerization, reconstitute TurboID, and initiate biotinylation.
• Demonstrated light-induced biotinylation and its cessation upon light removal in various cell lines.
• Benchmarked LAB against TurboID using E-cadherin as a model protein.

Main Results:

• LAB successfully maps protein-protein interactions with high accuracy and precision upon light activation.
• Light-induced dimerization of CRY2 and CIB1 effectively reconstitutes split-TurboID activity.
• Biotinylation is precisely controlled, initiating with light and halting upon its removal.
• LAB identified E-cadherin binding partners with significantly higher accuracy and fewer false positives than TurboID.

Conclusions:

• Light-activated BioID (LAB) offers a powerful, controllable tool for mapping protein-protein interactions.
• LAB enhances the precision of proximity labeling, especially for membrane proteins like E-cadherin.
• This technology provides a significant advancement for studying cellular interactions with reduced experimental noise.