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Target RNA recognition drives PIWI∗ complex assembly for transposon silencing
Júlia Portell-Montserrat1, Laszlo Tirian2, Changwei Yu2
1Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria; Institute of Molecular Pathology (IMP), Campus Vienna BioCenter, 1030 Vienna, Austria; Vienna BioCenter PhD Program, Doctoral School of the University of Vienna, Medical University of Vienna, Vienna, Austria.
Molecular Cell
|September 5, 2025
Summary
PIWI-interacting RNAs (piRNAs) and PIWI proteins silence transposons by forming PIWI* complexes. These complexes act as platforms to recruit downstream effectors, ensuring genome integrity.
Area of Science:
- Molecular Biology
- Genetics
- Epigenetics
Background:
- PIWI proteins and piRNAs are crucial for genome stability by silencing transposable elements.
- Silencing occurs via distinct nuclear and cytoplasmic pathways involving heterochromatin formation and RNA cleavage.
Purpose of the Study:
- To elucidate the mechanism of effector recruitment in PIWI-mediated silencing.
- To identify the molecular complexes involved in PIWI-piRNA guided target recognition.
Main Methods:
- Biochemical analysis of protein-RNA interactions.
- In vivo studies in Drosophila melanogaster.
- Evolutionary comparative analysis.
Main Results:
- Target engagement by PIWI-piRNA complexes forms PIWI* complexes, including GTSF proteins and Maelstrom.
- Nuclear PIWI* complexes recruit SFiNX for heterochromatin formation.
- Cytoplasmic Aubergine* complexes recruit Spindle-E for piRNA amplification.
Conclusions:
- PIWI* complexes serve as conserved molecular platforms coupling target recognition to effector recruitment.
- This mechanism provides a unifying principle for PIWI-mediated silencing across cellular compartments.
- Identifies a conserved ancient mechanism for genome defense.
Keywords:
Argonaute proteinsDrosophilaPIWI-piRNA pathwaygerm line biologyheterochromatin biologypiRNA biogenesisprotein structure predictionsmall RNA pathwaystransposon silencingMore Related Videos
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