AUF1 Cell Cycle Variations Define Genomic DNA Methylation by Regulation of DNMT1 mRNA Stability
Authors: Sachin R Tendulkar
Alexander Unterberger
Keisuke Shikimi
Moshe Szyf
Jerome Torrisani
Journal: Molecular and Cellular Biology (2007)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: DNA methylation; DNMT1; AUF1; cell cycle; mRNA destabilization
Affiliations: Department of Pharmacology and Therapeutics, McGill University, 3655 Sir William Osler Promenade, Montreal, Quebec H3G 1Y6, Canada., Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec
H3G 1Y6, Canada

Abstract:  DNA methylation is a major determinant of epigenetic inheritance. DNA methyltransferase 1 (DNMT1) is the enzyme responsible for the maintenance of DNA methylation patterns during cell division, and deregulated expression of DNMT1 leads to cellular transformation. We show herein that AU-rich element/poly(U)-binding/degradation factor 1 (AUF1)/heterogeneous nuclear ribonucleoprotein D interacts with an AU-rich conserved element in the 3' untranslated region of the DNMT1 mRNA and targets it for destabilization by the exosome. AUF1 protein levels are regulated by the cell cycle by the proteasome, resulting in cell cycle-specific destabilization of DNMT1 mRNA. AUF1 knock down leads to increased DNMT1 expression and modifications of cell cycle kinetics, increased DNA methyltransferase activity, and genome hypermethylation. Concurrent AUF1 and DNMT1 knock down abolishes this effect, suggesting that the effects of AUF1 knock down on the cell cycle are mediated at least in part by DNMT1. In this study, we demonstrate a link between AUF1, the RNA degradation machinery, and maintenance of the epigenetic integrity of the cell. 

Retracted: No

PubPeer comments:
 Figure 2E. Much more similar after horizontal flip than expected. ![file] , 
 #1  Similar perhaps, but if you think they are the same, that is not the least bit convincing. , 
 #2 it s more about the direction of the  shoe . , 
 #1 I personally performed this experiment during my post-doctoral position in Montreal. If you look at carefully the bands they are not strictly identical. It is true that they look similar , which was expected since this was the same radioactively labelled control RNA probe that was incubated with different cellular extracts (for the indicated time). This RNA probe did not contain any destabilizing AU-rich sequence so weakly degraded in any cellular extracts. The  direction of the shoe as mentioned in a previous comment is certainly due to the position of the sample on the gels. Samples loaded on lanes located on the edges of a polyacrylamide gel or loaded next to an empty lane (that I usually used to separate controls from test samples) often migrate with a  weird shape. People who do polyacrylamide gels would agree. The time 0 in the  CT was certainly loaded on the first lane of a gel. The time 30 in  p40, p42 and p45 samples were probably loaded next to an empty or an edge. I have to admit I do not remember. It was 15 years ago and I don t have my former lab books, they stayed in Montreal. I hope that my response have addressed your issues. Ju00e9ru00f4me Torrisani, PhD. , 
 #4 So no primary data? , 
 #5 I see no objective basis for concern about these data. Any further replies from the authors is of course voluntary, but in my opinion comments such as those in #3 and #5 don t warrant the time necessary to respond. ,