title: Polypyrimidine tract-binding protein is required for the repression of gene expression by all-trans retinoic acid.
abstract: All-trans retinoic acid is a key regulator of early development. High concentrations of retinoic acid interfere with differentiation and migration of neural crest cells. Here we report that a dinucleotide repeat in the cis-element of Snail2 (previously known as Slug) gene plays a role in repression by all-trans retinoic acid. We analyzed the cis-acting regulatory regions of the Xenopus Snail2 gene, whose expression is repressed by all-trans retinoic acid. The analysis identified a TG/CA repeat as a necessary element for the repression. By performing a yeast one-hybrid screen, we found that a polypyrimidine tract-binding protein (PTB), which is known to be a regulator of the alternative splicing of pre-messenger RNA, binds to the TG/CA repeat. Overexpression and knockdown experiments for PTB in HEK293 cells and Xenopus embryos indicated that PTB is required for repression by retinoic acid. The green fluorescent protein-PTB fusion protein was localized in the nucleus of 293T cells. In situ hybridization for PTB in Xenopus embryos showed that PTB is expressed at the regions including neural crest at the early stages. Our results indicate that PTB plays a role in the repression of gene expression by retinoic acid through binding to the TG/CA repeats.
authors.affiliation: Research Center for Stem Cell Engineering (SCRC), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan. y.tamanoue@aist.go.jp
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Tamanoue
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamagishi
authors.forename: Ikuko
authors.initials: I
authors.lastname: Hongo
authors.forename: Harumasa
authors.initials: H
authors.lastname: Okamoto
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D038941:Polypyrimidine Tract-Binding Protein / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000235:genetics*; D014212:Tretinoin / Q000494:pharmacology*; D014982:Xenopus laevis; D029961:Zebrafish Proteins / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; D029961:Zebrafish Proteins; C096850:snai1b protein, zebrafish; D038941:Polypyrimidine Tract-Binding Protein; D014212:Tretinoin