title: Bowline mediates association of the transcriptional corepressor XGrg-4 with Tbx6 during somitogenesis in Xenopus.
abstract: Prior to the somite segmentation, the cells in the anterior presomitic mesoderm (PSM) express a set of genes that is required for defining the segmental border and polarity of the prospective somite. However, little is known how the expression of these genes is repressed upon segmentation. Here we report that Bowline, an associate protein of the transcriptional corepressor XGrg-4, repressed Tbx6 dependent transcription of Thylacine1 by mediating interaction of Tbx6 with XGrg-4 in Xenopus laevis. In bowline-deficient embryos, segmental border formation was disturbed, and expression of Thylacine1, X-Delta-2, and bowline expanded anteriorly. Tbx6-dependent transcription of Thylacine1 was suppressed by Bowline, together with XGrg-4. We also found that Bowline mediated the interaction of Tbx6 and XGrg-4. Based on our findings, we conclude that a part of the transcriptional repression at the anterior end of the PSM is caused by Bowline mediated transcriptional repression of Tbx6-dependent gene expression in X. laevis.
authors.affiliation: Department of Life Sciences (Biology), Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Kondow
authors.forename: Keisuke
authors.initials: K
authors.lastname: Hitachi
authors.forename: Koji
authors.initials: K
authors.lastname: Okabayashi
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Hayashi
authors.forename: Makoto
authors.initials: M
authors.lastname: Asashima
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000502:physiology*; D056970:Co-Repressor Proteins; D004268:DNA-Binding Proteins / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D012097:Repressor Proteins / Q000378:metabolism*; D019170:Somites / Q000502:physiology*; D020825:T-Box Domain Proteins / Q000378:metabolism*; D015533:Transcriptional Activation / Q000502:physiology*; D029867:Xenopus Proteins / Q000378:metabolism*; D014982:Xenopus laevis / Q000196:embryology* / Q000502:physiology*
chemical_list: D056970:Co-Repressor Proteins; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D020825:T-Box Domain Proteins; C523700:TLE4 protein, Xenopus; C491181:Tbx6 protein, Xenopus; D029867:Xenopus Proteins; C512374:ripply2.2 protein, Xenopus