Regulation of Xenopus c-myc promoter activity in oocytes and embryos

Article Article scientifique Article Regulation of Xenopus c-myc promoter activity in oocytes and embryos eng 1993-03 author Modak Sohan Université de Genève, Département de Biologie Cellulaire, Geneva, Switzerland. 120487 author Principaud Etienne Auguste 23904 author Spohr Georges 25381 645-654 8437848 0950-9232 We have studied the regulation of transcription of the Xenopus c-myc I gene in oocytes and embryos. Various 5' and internal deletions of a 1310-bp-long c-myc I promoter fragment have been ligated upstream of the chloramphenicol acetyl transferase (CAT) reporter gene and microinjected into oocytes and fertilized eggs. Activity was determined by CAT assay and primer extension. The c-myc promoter drives transcription very efficiently, and a truncated promoter -158/+46 essentially retains full activity. This region contains an overlapping E2F/SP1 site and two tandem Sp1 sites homologous to those found in the c-myc gene of mouse. Internal deletions show that both elements are equally active in oocytes in driving the expression of CAT. A germinal vesicle extract contains a DNA-binding activity specific for an Sp1 consensus sequence but not the E2F site. The data suggest that the high transcription level of the endogenous c-myc gene in Xenopus oocytes is mediated by Sp1 or a related transcription factor. In embryos a different mechanism emerges and the functional role of the Sp1 binding sites appears to be less important. Animals Base Sequence Chloramphenicol O-Acetyltransferase / analysis Chloramphenicol O-Acetyltransferase / genetics Embryo, Nonmammalian / metabolism Female Genes, myc Molecular Sequence Data Oocytes / metabolism Promoter Regions, Genetic Transcription Factors / metabolism Transcription, Genetic Xenopus laevis / embryology Xenopus laevis / genetics Dewey 570 46 Département de biologie cellulaire 165 false Oncogene 8 3 8684da94-9c5d-4043-bde4-d75ae196df4e Article (Published version) Restricted Modak_ONC_19938645.pdf 6423179 application/pdf 231d02cef6f3a1f218b2135842e2d236893365997eee2d95f99fddacea8bbc76 restrictedAccess Faculté des sciences / Section de biologie / Département de biologie cellulaire

Title	Published in	Access level	OA Policy	Year	Views	Downloads

Regulation of Xenopus c-myc promoter activity in oocytes and embryos	Oncogene			1993	79	0

Archive ouverte UNIGE

Modak, Sohan