Human, bovine, canine and rat thyroglobulin promoter sequences display species-specific differences in an in vitro study.
The proximal promoter regions of the thyroglobulin gene from man, beef, dog and rat were compared by transient expression in primary cultured dog thyrocytes. All four promoter regions were able to control properly the expression of a reporter gene in response to cyclic AMP stimulation. Surprisingly, despite extensive sequence conservation, the transcriptional activities of these four mammalian thyroglobulin promoters were differently affected by equivalent mutations. Homologous sequence elements from these promoter regions also exhibited distinct binding characteristics in mobility-shift experiments conducted in the presence of nuclear proteins from bovine thyroids. Our observations show that the highly conserved thyroglobulin promoters may exhibit unexpected functional differences in a specific assay and indicate that some of the molecular mechanisms involved in the control of thyroglobulin gene expression have evolved differently within mammals.
Donda
A
A
IRIBHN, Faculté de Médecine, Hôpital Erasme, ULB-Erasme, Brussels, Belgium.
Javaux
F
F
Van Renterghem
P
P
Gervy-Decoster
C
C
Vassart
G
G
Christophe
D
D
D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002701:Chloramphenicol / Q000096:biosynthesis; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology; D004285:Dogs; D005786:Gene Expression Regulation; D005809:Genes, Regulator / Q000502:physiology; D013006:Growth Hormone / Q000096:biosynthesis; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics*; D051381:Rats; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D013954:Thyroglobulin / Q000096:biosynthesis / Q000235:genetics*; D013961:Thyroid Gland / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection
D005576:Colforsin; D002701:Chloramphenicol; D013006:Growth Hormone; D013954:Thyroglobulin; D000242:Cyclic AMP