title: JmjC Domain-containing Protein 6 (Jmjd6) Derepresses the Transcriptional Repressor Transcription Factor 7-like 1 (Tcf7l1) and Is Required for Body Axis Patterning during Xenopus Embryogenesis.
abstract: Tcf7l1 (also known as Tcf3) is a bimodal transcription factor that plays essential roles in embryogenesis and embryonic and adult stem cells. On one hand, Tcf7l1 works as transcriptional repressor via the recruitment of Groucho-related transcriptional corepressors to repress the transcription of Wnt target genes, and, on the other hand, it activates Wnt target genes when Wnt-activated β-catenin interacts with it. However, how its activity is modulated is not well understood. Here we demonstrate that a JmjC-domain containing protein, Jmjd6, interacts with Tcf7l and derepresses Tcf7l. We show that Jmjd6 binds to a region of Tcf7l1 that is also responsible for Groucho interaction, therefore making it possible that Jmjd6 binding displaces the Groucho transcriptional corepressor from Tcf7l1. Moreover, we show that Jmjd6 antagonizes the repression effect of Tcf7l1 on target gene transcription and is able to enhance β-catenin-induced gene activation and that, vice versa, inhibition of Jmjd6 activity compromises gene activation in both cells and Xenopus early embryos. We also show that jmjd6 is both maternally and zygotically transcribed during Xenopus embryogenesis. Loss of Jmjd6 function causes defects in anterioposterior body axis formation and down-regulation of genes that are involved in anterioposterior axis patterning. The results elucidate a novel mechanism underlying the regulation of Tcf7l1 activity and the regulation of embryonic body axis formation.
authors.affiliation: From the Model Animal Research Center of Nanjing University and the Ministry of Education Key Laboratory of Model Animals for Disease Study, Nanjing 210061, China.
authors.forename: Xuena
authors.initials: X
authors.lastname: Zhang
authors.affiliation: From the Model Animal Research Center of Nanjing University and the Ministry of Education Key Laboratory of Model Animals for Disease Study, Nanjing 210061, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: From the Model Animal Research Center of Nanjing University and the Ministry of Education Key Laboratory of Model Animals for Disease Study, Nanjing 210061, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Lu
authors.affiliation: From the Model Animal Research Center of Nanjing University and the Ministry of Education Key Laboratory of Model Animals for Disease Study, Nanjing 210061, China.
authors.forename: Zan
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: From the Model Animal Research Center of Nanjing University and the Ministry of Education Key Laboratory of Model Animals for Disease Study, Nanjing 210061, China.
authors.forename: Shengchun
authors.initials: S
authors.lastname: Gan
authors.affiliation: From the Model Animal Research Center of Nanjing University and the Ministry of Education Key Laboratory of Model Animals for Disease Study, Nanjing 210061, China.
authors.forename: Liyang
authors.initials: L
authors.lastname: Xu
authors.affiliation: From the Model Animal Research Center of Nanjing University and the Ministry of Education Key Laboratory of Model Animals for Disease Study, Nanjing 210061, China.
authors.forename: Anhua
authors.initials: A
authors.lastname: Lei
authors.affiliation: From the Model Animal Research Center of Nanjing University and the Ministry of Education Key Laboratory of Model Animals for Disease Study, Nanjing 210061, China caoying@nju.edu.cn.
authors.forename: Ying
authors.initials: Y
authors.lastname: Cao
mesh_terms: D000818:Animals; D001483:Base Sequence; D019521:Body Patterning; D056484:Jumonji Domain-Containing Histone Demethylases / Q000378:metabolism*; D011485:Protein Binding; D012097:Repressor Proteins / Q000378:metabolism*; D012689:Sequence Homology, Nucleic Acid; D014982:Xenopus laevis / Q000196:embryology*
chemical_list: D012097:Repressor Proteins; D056484:Jumonji Domain-Containing Histone Demethylases
keywords: Jmjd6; Tcf7l1; Wnt pathway; Xenopus; body axis patterning; derepression; development; embryo; transcription regulation