Specifying RNA-Binding Regions in Proteins by Peptide Cross-Linking and Affinity Purification

Area of Science:

• Molecular Biology
• Proteomics
• Gene Regulation

Background:

• RNA-binding proteins (RBPs) are crucial for gene expression regulation, but studying their specific RNA interaction sites is challenging.
• Many RBPs lack defined RNA-binding domains, complicating identification of RNA-protein interaction regions.
• Existing methods for mapping RNA-binding regions are often laborious and time-consuming.

Purpose of the Study:

• To develop a streamlined proteomic workflow for rapid characterization of RNA-binding regions in proteins.
• To establish a high-throughput method for mapping mRNA interaction sites of RBPs.
• To validate the method's accuracy and reproducibility in identifying known RNA-binding regions.

Main Methods:

• Peptide cross-linking and affinity purification (pCLAP) workflow.
• Combination of UV cross-linking, enzymatic RNA digestion, and mass spectrometry.
• Application to HEK293 cells to identify polyadenylated RNA-binding proteins and their interaction regions.

Main Results:

• Successfully mapped mRNA interaction regions for over 1000 RBPs in HEK293 cells.
• Demonstrated high reproducibility from replicate single-shot mass spectrometric analyses.
• Confirmed specificity by identifying known RNA-binding regions on known RBPs.

Conclusions:

• pCLAP is an efficient and accurate method for characterizing RNA-binding regions across a proteome.
• The method facilitates systems-level understanding of RNA-protein interactions.
• pCLAP has significant implications for studying diseases linked to RBP dysfunction, such as neurological disorders and cancer.