LRPPRC-mediated folding of the mitochondrial transcriptome.

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Mammalian mitochondrial gene expression involves transcription, RNA processing, translation, and decay.
• Mitochondrial RNA-protein interactions are crucial for gene expression but not fully understood.
• The mitochondrial transcriptome serves as a model for fundamental gene expression principles.

Purpose of the Study:

• To investigate the role of RNA-protein interactions in mitochondrial RNA folding.
• To elucidate the function of the LRPPRC-SLIRP complex in the mitochondrial transcriptome.
• To understand how RNA structure and stability are maintained for gene expression.

Main Methods:

• Combined RNase footprinting and Photoactivatable-Ribonucleoside-Enhanced Crosslinking and Immunoprecipitation (PAR-CLIP) at high resolution.
• Analysis of RNA secondary structure and stability.
• Assessment of RNA-protein binding patterns.

Main Results:

• LRPPRC, with its partner SLIRP, binds extensively across the mitochondrial transcriptome, particularly mRNAs.
• Loss of LRPPRC significantly impacts the secondary structure and stability of the entire transcriptome.
• The LRPPRC-SLIRP complex functions as a global RNA chaperone, stabilizing structures for biological accessibility.

Conclusions:

• Extensive RNA-protein interactions are vital for maintaining mitochondrial RNA accessibility and function.
• The LRPPRC-SLIRP complex plays a critical role in stabilizing mitochondrial RNA structures.
• This study reveals a fundamental mechanism ensuring RNA accessibility for translation, stabilization, and polyadenylation.