Computational screening of filamin mechanical binding proteins using AlphaFold2.

Area of Science:

• Biochemistry
• Cell Biology
• Biophysics

Background:

• Filamins are dimeric actin-binding proteins crucial for mechanical signaling.
• They possess a mechanosensory region (MSR) that transitions from a closed to an open conformation under mechanical stress.
• This conformational change exposes binding sites for various proteins, influencing diverse cellular functions.

Purpose of the Study:

• To screen for proteins that specifically recognize the open conformation of filamins using computational modeling.
• To identify novel mechanical binding partners of filamins in a cellular context.
• To establish a framework for understanding filamin interactions in mechanosignaling pathways.

Main Methods:

• Utilized AlphaFold2 modeling for in silico screening of potential filamin binding proteins.
• Focused on the Drosophila melanogaster filamin, Cheerio, for a biased screening approach.
• Characterized the top 132 identified hits for specific binding to the open MSR conformation.

Main Results:

• Identified 132 proteins that specifically bind to the open conformation of the filamin MSR.
• Confirmed that these identified proteins do not bind to the closed conformation of the MSR.
• Observed a lack of obvious sequence similarity in the binding regions of the identified proteins.
• Developed a method to filter out false positives based on secondary structure at the binding interface.

Conclusions:

• This study provides a computational framework for identifying filamin interaction partners involved in mechanosignaling.
• The findings highlight the context-dependent nature of filamin mechanical binding targets.
• The identified proteins represent potential key players in cellular responses to mechanical cues.