PETISCO is a novel protein complex required for 21U RNA biogenesis and embryonic viability

Area of Science:

• Developmental Biology
• RNA Biology
• Molecular Genetics

Background:

• Piwi proteins are essential for germ cell development, guided by small RNAs like piRNAs and 21U RNAs in C. elegans.
• While 21U RNA biogenesis factors are known, their interactions and functions remain largely uncharacterized.

Purpose of the Study:

• To identify and characterize novel protein complexes involved in 21U RNA biogenesis in C. elegans.
• To elucidate the functions of these complexes in both RNA processing and embryonic development.

Main Methods:

• Protein complex purification and characterization.
• RNA-binding assays and structural analysis of the PETISCO complex.
• Genetic analysis of novel proteins (PID-1, TOST-1) in C. elegans.

Main Results:

• A novel protein complex, PETISCO (PID-3, ERH-2, TOFU-6, IFE-3), essential for 21U RNA biogenesis, was identified.
• PETISCO interacts with capped 21U precursor RNA via its RNA-binding domains.
• A second function of PETISCO in embryonic development, mediated by TOST-1, was revealed, independent of 21U RNA biogenesis.
• Both PID-1 and TOST-1 interact with ERH-2, suggesting a conserved interaction motif.

Conclusions:

• PETISCO is a key complex for 21U RNA processing in C. elegans.
• The study reveals a dual role for PETISCO in RNA biogenesis and embryonic development.
• Data suggest a role for TOST-1:PETISCO in SL1 homeostasis, linking RNA processing to developmental pathways.