Reference : A TEF-1 binding motif that interacts with a placental protein is important for the tr...
Scientific journals : Article
Life sciences : Biochemistry, biophysics & molecular biology
A TEF-1 binding motif that interacts with a placental protein is important for the transcriptional activity of the hCS-B enhancer
Jacquemin, P. [> > > >]
Oury, Cécile mailto [Université de Liège - ULiège > Département des sciences biomédicales et précliniques > GIGA-R : Génétique générale et humaine >]
Belayew, A. [> > > >]
Martial, Joseph mailto [Université de Liège - ULiège > Département des sciences de la vie > GIGA-R : Biologie et génétique moléculaire >]
DNA & Cell Biology
Mary Ann Liebert, Inc.
Yes (verified by ORBi)
[en] Base Sequence ; Cell Line ; DNA-Binding Proteins/*metabolism ; *Enhancer Elements, Genetic ; Hela Cells ; Humans ; Molecular Sequence Data ; Molecular Weight ; Nuclear Proteins/*metabolism ; Oligodeoxyribonucleotides ; Peptides/metabolism ; Placental Lactogen/*genetics/metabolism ; Point Mutation ; Protein Binding ; Transcription Factors/*metabolism
[en] The transcriptional activity of the human placental lactogen genes (choriosomatomammotropic hormone, hCS) is controlled by tissue-specific enhancers located 4 kb downstream from their respective origins of transcription. The hCS-B enhancer is the strongest; its activity is mediated by synergism between two protein-binding sites (DF-3 and DF-4). The DF-4 site possesses a potential binding sequence for TEF-1, a known transcription factor. In this paper, we show by electrophoretic mobility-shift assays and antibody supershift experiments that TEF-1 does not bind to site DF-4. Mutations in the TEF-1-like binding motif of site DF-4 prevent formation of the DNA-protein complex, called complex f, in the presence of placental JEG-3 cell extracts. When HeLa cell extracts are used, another complex (complex c) is also affected. In transient expression experiments, TKCAT constructs linked to this mutated DF-4 site exhibit greatly reduced transcriptional activity when introduced into JEG-3 cells. Some cell lines contain both protein c and protein f (the proteins forming complexes c and f); when transfected, these lines display reduced DF-4-driven activity, suggesting that the two proteins could compete for the same DF-4 sequence. We conclude that protein f is important for the placenta-specific activity of the hCS-B enhancer. By UV cross-linking, we show that protein f is actually three polypeptides ranging in size from about 12 to 21 kD.

There is no file associated with this reference.

Bookmark and Share SFX Query

All documents in ORBi are protected by a user license.