Related Experiment Video
Updated: Apr 20, 2026
10:44
In Vitro Selection of Engineered Transcriptional Repressors for Targeted Epigenetic Silencing
Published on: May 5, 2023
2.2K
As time goes by: KRABs evolve to KAP endogenous retroelements
Michael Imbeault1, Didier Trono1
1School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
Developmental Cell
|December 3, 2014
Summary
Human endogenous retroelements are silenced during development. Researchers identified specific KRAB-ZNF proteins that repress L1 and SVA retrotransposons, revealing host-pathogen co-evolutionary dynamics.
Area of Science:
- Genomics
- Molecular Biology
- Evolutionary Biology
Background:
- Retroelements comprise approximately 50% of the human genome.
- These mobile genetic elements can both drive genomic evolution and compromise genome integrity.
- Silencing of retroelements is crucial during development.
Purpose of the Study:
- To identify sequence-specific factors that repress retroelements in the human genome.
- To understand the mechanisms by which the human genome controls potentially disruptive elements.
- To explore the evolutionary relationship between retroelements and their hosts.
Main Methods:
- Utilized bioinformatics and molecular biology techniques to analyze retroelement sequences.
- Investigated the function of KRAB-ZNF proteins in repressing specific retrotransposons.
- Focused on L1 and SVA retrotransposons in the human genome.
Main Results:
- Identified specific KRAB-ZNF proteins that bind to and repress distinct subsets of L1 and SVA retrotransposons.
- Demonstrated sequence-specific repression of these mobile elements by KRAB-ZNF proteins.
- Provided evidence for an active defense mechanism against retroelements in the human genome.
Conclusions:
- KRAB-ZNF proteins play a key role in silencing retroelements during human development.
- This repression mechanism highlights an ongoing evolutionary arms race between the host genome and retroelements.
- Understanding these interactions is vital for comprehending genome evolution and stability.
More Related Videos
Related Concept Videos
03:08LTR Retrotransposons
20.6K
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...
20.6K
02:32Exon Recombination
4.3K
The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon...
Exon shuffling follows “splice frame rules.” Each exon...
4.3K
02:33Retroviruses
16.3K
Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
16.3K
03:18Non-LTR Retrotransposons
14.1K
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...
14.1K
02:13Overview of Transposition and Recombination
21.3K
Transposons make up a significant part of genomes of various organisms. Therefore, it is believed that transposition played a major evolutionary role in speciation by changing genome sizes and modifying gene expression patterns. For example, in bacteria, transposition can lead to conferring antibiotic resistance. Movement of transposable elements within the genetic pool of pathogenic bacteria can aid in transfer of antibiotic-resistant genetic elements. In eukaryotes, transposons can carry out...
21.3K
02:53Conservative Site-specific Recombination and Phase Variation
7.4K
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
7.4K