Binding of 14-3-3 reader proteins to phosphorylated DNMT1 facilitates aberrant DNA methylation and gene expression

• Type of Material: Article
• Authors: Pierre-Olivier Estève, New England Biolabs Inc; Guoqiang Zhang, New England Biolabs Inc; V.K. Chaithanya Ponnaluri, New England Biolabs Inc; Kanneganti Deepti, New England Biolabs Inc; Hang Gyeong Chin, New England Biolabs Inc; Nan Dai, New England Biolabs Inc; Cari Sagum, University of Texas; Karynne Black, University of Texas; Ivan R. Corrêa, Jr., New England Biolabs Inc; Mark T. Bedford, University of Texas; Xiaodong Cheng, Emory University; Sriharsa Pradhan, New England Biolabs Inc
• Language: English
• Date: 2016-02-29
• Publisher: Oxford University Press (OUP)
• Publication Version: Final Published Version
• Copyright Statement: © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.
• License: Creative Commons Attribution-NonCommercial 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1093/nar/gkv1162
• Title of Journal or Parent Work: Nucleic Acids Research
• ISSN: 0305-1048
• Volume: 44
• Issue: 4
• Start Page: 1642
• End Page: 1656
• Grant/Funding Information: Funding for open access charge: New England Biolabs Inc.; New England Biolabs Inc.; Cancer Prevention Research Institute of Texas [RP130432 to M.T.B.]; Center for Environmental and Molecular Carcinogenesis at MD Anderson; X.C.'s laboratory was supported by NIH [GM049245-22].
• Research Categories: Chemistry, Biochemistry; Biology, Genetics

Abstract

Mammalian DNA (cytosine-5) methyltransferase 1 (DNMT1) is essential for maintenance methylation. Phosphorylation of Ser143 (pSer143) stabilizes DNMT1 during DNA replication. Here, we show 14-3-3 is a reader protein of DNMT1pSer143. In mammalian cells 14-3-3 colocalizes and binds DNMT1pSer143 post-DNA replication. The level of DNMT1pSer143 increased with overexpression of 14-3-3 and decreased by its depletion. Binding of 14-3-3 proteins with DNMT1pSer143 resulted in inhibition of DNA methylation activity in vitro. In addition, overexpression of 14-3-3 in NIH3T3 cells led to decrease in DNMT1 specific activity resulting in hypomethylation of the genome that was rescued by transfection of DNMT1. Genes representing cell migration, mobility, proliferation and focal adhesion pathway were hypomethylated and overexpressed. Furthermore, overexpression of 14-3-3 also resulted in enhanced cell invasion. Analysis of TCGA breast cancer patient data showed significant correlation for DNA hypomethylation and reduced patient survival with increased 14-3-3 expressions. Therefore, we suggest that 14-3-3 is a crucial reader of DNMT1pSer143 that regulates DNA methylation and altered gene expression that contributes to cell invasion.