Related Experiment Video
Updated: Aug 7, 2026
11:19
Novel RNA-Binding Proteins Isolation by the RaPID Methodology
Published on: September 30, 2016
The ARE-associated factor AUF1 binds poly(A) in vitro in competition with PABP
Francis Sagliocco1, Benoît Laloo, Bertrand Cosson
1INSERM, E362, Bordeaux, F-33076 France.
The Biochemical Journal
|July 13, 2006
Summary
AUF1 (AU-rich element RNA-binding protein 1) binds to poly(A) tails, potentially competing with PABP (poly(A)-binding protein). This suggests AUF1 may regulate mRNA stability and translation by influencing poly(A) tail association.
Area of Science:
- Molecular Biology
- RNA Biology
- Gene Regulation
Background:
- AU-rich elements (AREs) control mRNA turnover and translation via poly(A) tail shortening.
- Mechanisms of ARE-mediated deadenylation by ARE-binding proteins (ARE-BPs) are not fully understood.
- ARE-BPs may interfere with poly(A)-binding protein (PABP) association to facilitate deadenylation.
Purpose of the Study:
- To investigate whether AUF1 (AU-rich element RNA-binding protein 1), an mRNA-destabilizing ARE-BP, interacts with the poly(A) tail.
- To determine if AUF1 binding to the poly(A) tail is dependent on the ARE sequence.
- To assess the potential competition between AUF1 and PABP for poly(A) tail binding in vivo.
Main Methods:
- In vitro binding assays using endogenous and recombinant AUF1 isoforms with poly(A) sequences and polyadenylated RNA probes.
- Competition assays to evaluate AUF1's displacement of PABP from the poly(A) tail.
- Quantification of AUF1 and PABP molar concentrations in HeLa cell cytoplasm and nucleus.
Main Results:
- Endogenous and recombinant AUF1 proteins bind specifically to poly(A) sequences in vitro, independent of PABP and ARE sequences.
- AUF1 binding to poly(A) exhibits oligomeric and cooperative properties, and AUF1 efficiently displaces PABP.
- AUF1 is present at significant concentrations in both the cytoplasm and nucleus of HeLa cells, comparable to PABP.
Conclusions:
- AUF1 directly binds to poly(A) tails in vitro.
- AUF1 can compete with PABP for poly(A) tail binding, suggesting a novel mechanism for mRNA regulation.
- These findings imply a role for AUF1 in controlling PABP-poly(A) tail association, impacting mRNA stability and translation.
Related Concept Videos
01:19Allosteric Proteins-ATCase
Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
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...
02:41Chromatin Structure Regulates pre-mRNA Processing
In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into functional proteins. For a long time, transcription and pre-mRNA processing were considered two independent events that occur sequentially in the cell. However, it has now been well established that transcription and pre-mRNA processing are two simultaneous processes that are precisely regulated inside the cell.
The chromatin structure, especially...
The chromatin structure, especially...
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...
02:13Cooperative Binding of Transcription Regulators
Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form dimers that...
00:49Ligand Binding and Linkage
Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked. In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence the...