Human Molecular Genetics Advance Access originally published online on April 29, 2009
Human Molecular Genetics 2009 18(14):2599-2608; doi:10.1093/hmg/ddp194
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The role of N-acetylglucosaminyltransferase III and V in the post-transcriptional modifications of E-cadherin
1 Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Rua Dr Roberto Frias s/n, 4200-465 Porto, Portugal 2 Institute of Biomedical Sciences of Abel Salazar (ICBAS), University of Porto, Largo Prof. Abel Salazar, 2, 4099-003 Porto, Portugal 3 Medical Faculty, University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal
* To whom correspondence should be addressed. Tel: +351 225570700; Fax: +351 225570799; Email: celsor{at}ipatimup.pt
Received April 3, 2009; Accepted April 27, 2009
It has long been recognized that E-cadherin dysfunction is a major cause of epithelial cell invasion. However, very little is known about the post-transcriptional modifications of E-cadherin and its role in E-cadherin mediated tumor progression. N-acetylglucosaminyltransferase III (GnT-III) catalyzes the formation of a bisecting GlcNAc structure in N-glycans, and has been pointed as a metastasis suppressor. N-acetylglucosaminyltransferase V (GnT-V) catalyzes the addition of β1,6 GlcNAc branching of N-glycans, and has been associated to increase metastasis. The regulatory mechanism between E-cadherin expression and the remodeling of its oligosaccharides structures by GnT-III and GnT-V were explored in this study. We have demonstrated that wild-type E-cadherin regulates MGAT3 gene transcription resulting in increased GnT-III expression. We also showed that GnT-III and GnT-V competitively modified E-cadherin N-glycans. The GnT-III knockdown cells revealed a membrane de-localization of E-cadherin leading to its cytoplasmic accumulation. Further, the GnT-III knockdown cells also caused modifications of E-cadherin N-glycans catalyzed by GnT-III and GnT-V. Altogether our results have clarified the existence of a bidirectional crosstalk between E-cadherin and GnT-III/GnT-V that was, for the first time, reproduced in an in vivo model. This study opens new insights into the post-transcriptional modifications of E-cadherin in its biological function, in a tumor context.