RNA regulatory networks diversified through curvature of the PUF protein scaffold

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• PUF proteins are key RNA-binding proteins regulating mRNA localization, translation, and stability.
• These proteins play critical roles in cellular processes such as development, stem cell maintenance, and memory formation.

Purpose of the Study:

• To identify the specific messenger RNA (mRNA) targets of the Saccharomyces cerevisiae PUF protein, Puf5p.
• To elucidate the structural basis and functional implications of Puf5p-RNA interactions.

Main Methods:

• High-throughput sequencing combined with ultraviolet crosslinking and affinity purification (HITS-CLIP) was employed to map Puf5p binding sites on mRNA.
• Crystal structures of Puf5p-RNA complexes were determined to visualize protein-RNA interactions at atomic resolution.

Main Results:

• Puf5p recognizes diverse mRNA binding sites with variable spacer lengths between conserved sequences.
• Each distinct binding site length was correlated with a specific biological function.
• Crystal structures revealed a flat, extended protein-RNA interaction surface for Puf5p, which remains unchanged with varying RNA lengths.
• A single PUF protein repeat was found to be sufficient for broadening RNA binding specificity.

Conclusions:

• Puf5p's unique protein architecture enables broad mRNA target recognition, influencing diverse biological functions.
• Variations in protein structure, like altered curvature, may drive the evolution of mRNA regulatory networks.
• Understanding Puf5p-RNA interactions provides insights into post-transcriptional gene regulation and its role in cellular processes.