title: Molecular cloning and expression of the chromatin insulator protein CTCF in Xenopus laevis.
abstract: The zinc finger protein CTCF has been shown to mediate multiple functions connected to gene repression. Transcriptional inhibition as well as enhancer blocking and chromatin insulation are documented for CTCF in men, mice and chickens. Additionally, hCTCF has been linked to epigenetics and disease. In line with these basic cellular functions, CTCF has been found to be expressed in every cell type and adult tissue tested and has thus been deemed an ubiquitous protein. Here, we report the identification of the CTCF homologue from Xenopus and the analysis of the spatio-temporal expression of xCTCF during embryogenesis. Within the DNA binding domain, xCTCF is virtually identical to other identified vertebrate CTCF proteins. Homology also extends to other conserved regions that are important for CTCF function. Although xCTCF mRNA is present during all stages of early Xenopus development, a remarkable increase in expression is observed in neuronal tissues. Early in development, xCTCF is highly expressed in the neural plate and later in the neural tube and developing brain. By tailbud stage, elevated expression is also seen in the developing sensory organs of the head. This is the first detailed description of the expression pattern of a vertebrate insulator protein during embryogenesis.
authors.affiliation: Institute for Genetics, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 58-62, D-35392, Germany. leslie.burke@gen.bio.uni-giessen.de
authors.forename: Les J
authors.initials: LJ
authors.lastname: Burke
authors.forename: Thomas
authors.initials: T
authors.lastname: Hollemann
authors.forename: Tomas
authors.initials: T
authors.lastname: Pieler
authors.forename: Rainer
authors.initials: R
authors.lastname: Renkawitz
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000076246:CCCTC-Binding Factor; D002843:Chromatin / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009432:Neural Crest / Q000196:embryology / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D012097:Repressor Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics*; D014981:Xenopus; D014982:Xenopus laevis
chemical_list: D000076246:CCCTC-Binding Factor; C000619697:CTCF protein, human; D002843:Chromatin; C000619698:Ctcf protein, mouse; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D012097:Repressor Proteins; D014157:Transcription Factors