Jacqueline R Ha1, Li Hao1, Geetha Venkateswaran1, Yu Hao Huang1, Elizabeth Garcia1, Sujata Persad2. 1. Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada T6G 2E1. 2. Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada T6G 2E1. Electronic address: sujata.persad@ualberta.ca.
Abstract
BACKGROUND: We have previously reported that β-catenin is post-translationally modified with a single O-linked attachment of β-N-acetyl-glucosamine (O-GlcNAc). We showed that O-GlcNAc regulated β-catenin's subcellular localization and transcriptional activity. OBJECTIVE: The objectives of this investigation were to identify the putative O-GlcNAc sites of β-catenin and the relevance of identified sites in the regulation of β-catenin's localization and transcriptional activity. METHOD: Missense mutations were introduced to potential O-GlcNAc sites of pEGFP-C2-N-Terminal- or pEGFP-C2-Wild Type-β-catenin by site-directed mutagenesis. We determined the levels of O-GlcNAc-β-catenin, subcellular localization, interaction with binding partners and transcriptional activity of the various constructs. RESULTS: Serine 23 of β-catenin was determined as a site for O-GlcNAc modification which regulated its subcellular distribution, its interactions with cellular partners and consequently its transcriptional activity. SIGNIFICANCE: O-GlcNAcylation of Serine 23 is a novel regulatory modification for β-catenin's subcellular localization and transcriptional activity. This study is the first report to characterize site specific regulation of β-catenin by the O-GlcNAc modification.
BACKGROUND: We have previously reported that β-catenin is post-translationally modified with a single O-linked attachment of β-N-acetyl-glucosamine (O-GlcNAc). We showed that O-GlcNAc regulated β-catenin's subcellular localization and transcriptional activity. OBJECTIVE: The objectives of this investigation were to identify the putative O-GlcNAc sites of β-catenin and the relevance of identified sites in the regulation of β-catenin's localization and transcriptional activity. METHOD: Missense mutations were introduced to potential O-GlcNAc sites of pEGFP-C2-N-Terminal- or pEGFP-C2-Wild Type-β-catenin by site-directed mutagenesis. We determined the levels of O-GlcNAc-β-catenin, subcellular localization, interaction with binding partners and transcriptional activity of the various constructs. RESULTS:Serine 23 of β-catenin was determined as a site for O-GlcNAc modification which regulated its subcellular distribution, its interactions with cellular partners and consequently its transcriptional activity. SIGNIFICANCE: O-GlcNAcylation of Serine 23 is a novel regulatory modification for β-catenin's subcellular localization and transcriptional activity. This study is the first report to characterize site specific regulation of β-catenin by the O-GlcNAc modification.