title: The binding sites for Xenopus laevis FIII/YY1 in the first exon of L1 and L14 ribosomal protein genes are dispensable for promoter expression.
abstract: The genes coding for the ribosomal proteins (rp genes) L14 and L1 in the toad Xenopus laevis are contacted in the first exon by the frog protein, FIII/YY1, homolog of the human zinc-finger protein YY1, acting as repressor, activator and initiator of transcription. To investigate the functional significance of FIII/YY1 in the context of the two rp genes, the L14 region at nucleotide positions -105 to +44, including all of the first exon was linked to the chloramphenicol acetyltransferase (CAT) reporter gene; constructs with wild-type and mutated sites for FIII/YY1 were injected into nuclei of stage V-VI oocytes and analyzed for CAT activity. The same procedure was followed for constructs made with L1 sequences at nucleotide positions -17 to +1567. Mutations in the sites for FIII/YY1 did not change reporter activity, nor did overexpression of FIII/YY1 in the oocytes prior to injection with L1 and L14 constructs. Since oocytes are non-dividing cells, transfections were made of Xenopus kidney cells in culture with the same constructs and the results obtained in oocytes confirmed.
authors.affiliation: Dipartimento di Genetica e Biologia Molecolare, Università di Roma La Sapienza, Italy.
authors.forename: E
authors.initials: E
authors.lastname: De Rinaldis
authors.forename: G
authors.initials: G
authors.lastname: Pisaneschi
authors.forename: O
authors.initials: O
authors.lastname: Camacho-Vanegas
authors.forename: E
authors.initials: E
authors.lastname: Beccari
mesh_terms: D000818:Animals; D001665:Binding Sites; D004268:DNA-Binding Proteins / Q000378:metabolism*; D050981:Erythroid-Specific DNA-Binding Factors; D005091:Exons; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012269:Ribosomal Proteins / Q000235:genetics*; D014157:Transcription Factors / Q000378:metabolism*; D029867:Xenopus Proteins; D014982:Xenopus laevis; D050986:YY1 Transcription Factor
chemical_list: D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D012269:Ribosomal Proteins; D014157:Transcription Factors; D029867:Xenopus Proteins; D050986:YY1 Transcription Factor; C494701:YY1 protein, Xenopus; C028546:ribosomal protein L1; C041174:ribosomal protein L14