Related Experiment Video
Updated: May 22, 2026
09:42
Immunostaining for DNA Modifications: Computational Analysis of Confocal Images
Published on: September 7, 2017
RNA-directed DNA methylation: getting a grip on mechanism.
1Brown University, MCB Department, Providence, RI 02912, USA. judith_bender@brown.edu
Current Biology : CB
|May 26, 2012
Summary
Small RNAs guide gene silencing by directing chromatin modifications to specific genomic locations. A new ATPase complex in Arabidopsis acts as a molecular gripper in this small RNA-guided pathway.
Area of Science:
- Genetics
- Molecular Biology
- Epigenetics
Background:
- Small RNAs are crucial regulators of gene expression.
- They guide epigenetic modifications to target genomic loci, including transposons and repetitive elements.
- Understanding the machinery involved in this guidance is essential for deciphering gene regulation.
Purpose of the Study:
- To identify novel components involved in small RNA-guided chromatin modification.
- To characterize the function of these components in the guidance pathway.
Main Methods:
- Arabidopsis thaliana genetic screen.
- Analysis of chromatin modifications.
- Biochemical assays to characterize protein complexes.
Main Results:
- A genetic screen identified a novel ATPase complex essential for small RNA-guided gene silencing.
- This complex appears to function as a molecular gripper, facilitating the guidance process.
- The ATPase complex is recruited to target genomic regions by small RNAs.
Conclusions:
- A novel ATPase complex is a key component of the small RNA-guided epigenetic machinery.
- This complex likely plays a critical role in the dynamic recruitment and anchoring of silencing factors to target DNA sequences.
- The findings provide new insights into the molecular mechanisms of transposon and repeat silencing.
More Related Videos
Related Concept Videos
01:37Epigenetic Regulation
Epigenetic changes alter the physical structure of the DNA without changing the genetic sequence and often regulate whether genes are turned on or off. This regulation ensures that each cell produces only proteins necessary for its function. For example, proteins that promote bone growth are not produced in muscle cells. Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.
X-chromosome...
X-chromosome...
01:46Epigenetic Regulation
Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.
01:17Phase II Reactions: Methylation Reactions
Methylation is a phase II biotransformation process involving the attachment of a methyl group to a substrate. Enzymes known as methyltransferases orchestrate this reaction.
The mechanism of methylation unfolds in two stages. The first stage sees a methyltransferase enzyme facilitating the transfer of a methyl group from S-adenosylmethionine (SAM) to the substrate, forming S-adenosylhomocysteine (SAH). The second stage involves further metabolism of SAH into homocysteine, which can be recycled...
The mechanism of methylation unfolds in two stages. The first stage sees a methyltransferase enzyme facilitating the transfer of a methyl group from S-adenosylmethionine (SAM) to the substrate, forming S-adenosylhomocysteine (SAH). The second stage involves further metabolism of SAH into homocysteine, which can be recycled...
01:28Biosynthesis of Nucleic Acids
Nucleic acid biosynthesis is a fundamental biochemical process that produces the purine and pyrimidine nucleotides essential for DNA and RNA synthesis. This pathway maintains a balanced nucleotide pool, preventing imbalances that could jeopardize genetic integrity and cellular function. Given the crucial role of nucleotides, their synthesis is tightly regulated to ensure proper cellular homeostasis.Purine BiosynthesisThe biosynthesis of purine nucleotides begins with ribose-5-phosphate, a...
02:32Histone Modification
The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression.
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
02:25Spreading of Chromatin Modifications
The histone proteins in the nucleosomes are post-translationally modified (PTM) to increase or decrease access to DNA. The commonly observed PTMs are methylation, acetylation, phosphorylation, and ubiquitination of lysine amino acids in the histone H3 tail region. These histone modifications have specific meaning for the cell. Hence, they are called "histone code". The protein complex involved in histone modification is termed as "reader-writer" complex.
Writers
The writer is an enzyme that can...
Writers
The writer is an enzyme that can...