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Updated: Aug 12, 2025
11:52
Analysis of LINE-1 Retrotransposition at the Single Nucleus Level
Published on: April 23, 2016
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Ribonucleoprotein condensation driven by retrotransposon LINE-1 sustains RNA integrity and translation in mouse
Biorxiv : the Preprint Server for Biology
|January 30, 2023
Summary
Transposable elements like LINE-1 (L1) can proliferate excessively. In piRNA-deficient mice, ORF1p condensates promote L1 propagation without impacting endogenous RNA metabolism.
Area of Science:
- Molecular Biology
- Genetics
- Epigenetics
Background:
- Transposable elements (TEs) are mobile DNA sequences that can endanger the host genome upon excessive proliferation.
- Animals possess defense mechanisms, such as Piwi-interacting (pi)RNAs, to suppress TE activity.
- LINE-1 (L1) retrotransposons are abundant in humans and mice, indicating successful evasion of host defenses.
Approach:
- Characterized L1 Bodies (LBs) and ORF1p complexes in germ cells of piRNA-deficient Maelstrom null mice.
- Investigated interactions of ORF1p with TE RNAs, genic mRNAs, and stress granule proteins.
- Examined the association of ORF1p with the CCR4-NOT deadenylation complex and Protein Kinase R activator (PRKRA).
- Studied the effects of PRKRA on L1 in cultured cells to understand its role in L1 propagation.
Key Points:
- ORF1p interacts with TE RNAs, mRNAs, and stress granule proteins.
- ORF1p associates with negative RNA regulators (CCR4-NOT, PRKRA), yet LB-localized mRNA stability and translation are unaffected.
- PRKRA elevates ORF1p levels and L1 retrotransposition in cultured cells.
Conclusions:
- ORF1p-driven condensates, or L1 Bodies, facilitate L1 propagation.
- L1 propagation occurs independently of endogenous RNA metabolism regulation.
- Understanding L1 persistence mechanisms is crucial for genome stability.
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