title: Transcriptional and functional studies of Human Endogenous Retrovirus envelope EnvP(b) and EnvV genes in human trophoblasts.
abstract: HERV (Human Endogenous Retrovirus)-encoded envelope proteins are implicated in the development of the placenta. Indeed, Syncytin-1 and -2 play a crucial role in the fusion of human trophoblasts, a key step in placentation. Other studies have identified two other HERV env proteins, namely EnvP(b) and EnvV, both expressed in the placenta. In this study, we have fully characterized both env transcripts and their expression pattern and have assessed their implication in trophoblast fusion. Through RACE analyses, standard spliced transcripts were detected, while EnvV transcripts demonstrated alternative splicing at its 3' end. Promoter activity and expression of both genes were induced in forskolin-stimulated BeWo cells and in primary trophoblasts. Although we have confirmed the fusogenic activity of EnvP(b), overexpression or silencing experiments revealed no impact of this protein on trophoblast fusion. Our results demonstrate that both env genes are expressed in human trophoblasts but are not required for syncytialization.
authors.affiliation: Université du Québec à Montréal, Département des sciences biologiques and Centre de recherche BioMed, 2080 St-Urbain, Montréal, Québec, Canada H2X 3X8. amandine.vargas@voila.fr
authors.forename: Amandine
authors.initials: A
authors.lastname: Vargas
authors.forename: Maxime
authors.initials: M
authors.lastname: Thiery
authors.forename: Julie
authors.initials: J
authors.lastname: Lafond
authors.forename: Benoit
authors.initials: B
authors.lastname: Barbeau
mesh_terms: D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002459:Cell Fusion; D002460:Cell Line; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D020077:Endogenous Retroviruses / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015686:Gene Products, env / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D015752:Genes, env; D006801:Humans; D008969:Molecular Sequence Data; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D011401:Promoter Regions, Genetic; D014327:Trophoblasts / Q000378:metabolism / Q000502:physiology*
chemical_list: D015686:Gene Products, env