title: The role of N-acetylglucosaminyltransferase III and V in the post-transcriptional modifications of E-cadherin.
abstract: 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 beta1,6 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.
authors.affiliation: Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Rua Dr Roberto Frias s/n, 4200-465 Porto, Portugal.
authors.forename: Salomé S
authors.initials: SS
authors.lastname: Pinho
authors.forename: Celso A
authors.initials: CA
authors.lastname: Reis
authors.forename: Joana
authors.initials: J
authors.lastname: Paredes
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Magalhães
authors.forename: António Carlos
authors.initials: AC
authors.lastname: Ferreira
authors.forename: Joana
authors.initials: J
authors.lastname: Figueiredo
authors.forename: Wen
authors.initials: W
authors.lastname: Xiaogang
authors.forename: Fátima
authors.initials: F
authors.lastname: Carneiro
authors.forename: Fátima
authors.initials: F
authors.lastname: Gärtner
authors.forename: Raquel
authors.initials: R
authors.lastname: Seruca
mesh_terms: D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D015870:Gene Expression; D006031:Glycosylation; D006801:Humans; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism
chemical_list: D015820:Cadherins; D017351:N-Acetylglucosaminyltransferases; C054599:beta-1,4-mannosyl-glycoprotein beta-1,4-N-acetylglucosaminyltransferase; C052254:alpha-1,6-mannosylglycoprotein beta 1,6-N-acetylglucosaminyltransferase