RNA interference is mediated by 21- and 22-nucleotide RNAs
S M Elbashir1, W Lendeckel, T Tuschl
1Department of Cellular Biochemistry, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany.
Genes & Development
|February 7, 2001
Summary
Short interfering RNAs (siRNAs) are the key mediators of RNA interference (RNAi). These 21- and 22-nucleotide fragments are generated from double-stranded RNA (dsRNA) and precisely cleave target RNA sequences.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- Double-stranded RNA (dsRNA) triggers sequence-specific gene silencing via RNA interference (RNAi).
- The precise molecular mechanisms and intermediate molecules of RNAi were not fully elucidated.
Purpose of the Study:
- To identify the specific RNA molecules mediating RNA interference.
- To characterize the processing of dsRNA into active silencing agents.
- To determine the mechanism of target RNA cleavage by these agents.
Main Methods:
- Utilized a Drosophila in vitro system to study RNA interference.
- Synthesized and tested chemically 21- and 22-nucleotide short interfering RNA (siRNA) duplexes.
- Analyzed the cleavage products of target RNA in the presence of siRNAs and cellular lysates.
Main Results:
- Demonstrated that 21- and 22-nucleotide RNA fragments, termed short interfering RNAs (siRNAs), are the sequence-specific mediators of RNAi.
- Showed that siRNAs are generated through an RNase III-like processing of long dsRNA.
- Confirmed that synthesized siRNA duplexes efficiently induce target RNA cleavage at a site near the center of the siRNA-guided region.
- Provided evidence that dsRNA processing direction influences target RNA cleavage (sense vs. antisense).
Conclusions:
- Short interfering RNAs (siRNAs) are the essential molecules responsible for sequence-specific gene silencing in RNA interference.
- The generation of siRNAs involves a precise enzymatic processing of dsRNA.
- The orientation of dsRNA processing dictates the specificity of target RNA cleavage.
Related Concept Videos
01:23Types of RNA
Overview
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
01:23RNA Interference
RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated.
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
01:23RNA Interference
RNA interference (RNAi) is a process in which a small non-coding RNA molecule blocks the post-transcriptional expression of a gene by binding to its messenger RNA (mRNA) and preventing the protein from being translated.
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
02:30siRNA - Small Interfering RNAs
Small interfering RNAs, or siRNAs, are short regulatory RNA molecules that can silence genes post-transcriptionally, as well as the transcriptional level in some cases. siRNAs are important for protecting cells against viral infections and silencing transposable genetic elements.
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent...
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent...
02:15Experimental RNAi
RNA interference (RNAi) is a cellular mechanism that inhibits gene expression by suppressing its transcription or activating the RNA degradation process. The mechanism was discovered by Andrew Fire and Craig Mello in 1998 in plants. Today, it is observed in almost all eukaryotes, including protozoa, flies, nematodes, insects, parasites, and mammals. This precise cellular mechanism of gene silencing has been developed into a technique that provides an efficient way to identify and determine the...
01:20Types of RNA
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in regulating gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA Performs Diverse...
RNA Performs Diverse...