Related Experiment Video
Updated: May 19, 2026
11:52
Analysis of LINE-1 Retrotransposition at the Single Nucleus Level
Published on: April 23, 2016
Poly(A) binding protein C1 is essential for efficient L1 retrotransposition and affects L1 RNP formation
Lixin Dai1, Martin S Taylor, Kathryn A O'Donnell
1High Throughput Biology Center, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Molecular and Cellular Biology
|August 22, 2012
Summary
Poly(A) binding proteins (PABPs) are crucial for L1 retrotransposon activity. Depleting PABPC1 impairs L1 RNP formation, while modulating PABPN1 and PABPC1 levels affects L1 retrotransposition efficiency.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- Poly(A) binding proteins (PABPs) bind mRNA poly(A) tails, influencing RNA polyadenylation, translation, and stability.
- L1 non-long-terminal-repeat (non-LTR) retrotransposons utilize cellular machinery for their propagation.
Purpose of the Study:
- To investigate the role of Poly(A) binding proteins (PABPN1 and PABPC1) in L1 retrotransposition.
- To elucidate the mechanism by which PABPs affect L1 retrotransposon activity.
Main Methods:
- Utilized a modified L1 retrotransposition vector in HeLa and HEK293T cells.
- Employed RNA interference (RNAi) for gene knockdown and assessed L1 retrotransposition rates.
- Analyzed L1 ribonucleoprotein (RNP) complex formation and protein expression levels.
Main Results:
- Knockdown of PABPN1 and PABPC1 reduced L1 retrotransposition by 70-80% without affecting L1 transcription, translation, or poly(A) tail status.
- Both PABPs were found to associate with the L1 RNP complex.
- PABPC1 depletion disrupted L1 RNP formation, while PAIP2 knockdown (PABPC1 inhibitor) increased L1 retrotransposition.
- Modulated PABPN1/PABPC1 expression affected L1 retrotransposition, with unregulated overexpression leading to decreased activity.
Conclusions:
- PABPC1 is essential for L1 RNP complex formation and potentially L1 RNP translocation.
- PABPs play a significant regulatory role in L1 retrotransposon activity, impacting RNP complex dynamics.
Related Concept Videos
03:08LTR Retrotransposons
LTR retrotransposons are class I transposable elements with long terminal repeats flanking an internal coding region. These elements are less abundant in mammals compared to other class I transposable elements. About 8 percent of human genomic DNA comprises LTR retrotransposons. Some of the common examples of LTR retrotransposons are Ty elements in yeast and Copia elements in Drosophila.
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...
02:57piRNA - Piwi-interacting RNAs
PIWI-interacting RNAs, or piRNAs, are the most abundant short non-coding RNAs. More than 20,000 genes have been found in humans that code for piRNAs while only 2000 genes have been found for miRNAs. piRNAs can act at the transcriptional and post-transcriptional levels and have a vital role in silencing transposable elements present in germ cells. They are also involved in epigenetic silencing and activation. Previously, they were thought to function only in germ cells but new evidence suggests...
03:18Non-LTR Retrotransposons
As the name suggests, non-LTR retrotransposons lack the long terminal repeats characteristic of the LTR retrotransposons. Additionally, both LTR and non-LTR retrotransposons use distinct mechanisms of mobilization. Non-LTR retrotransposons are further divided into two classes - Long interspersed nuclear elements (LINEs) and short interspersed nuclear elements (SINEs), both of which occur abundantly in most mammals, including humans. Some of the active non-LTR retrotransposons in humans are L1...
02:36RNA Polymerase II Accessory Proteins
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...
02:36RNA Polymerase II Accessory Proteins
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...
00:43Bacterial RNA Polymerase
Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity.
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...