Expression of a transactivation-deficient form of thyroid transcription factor I decreases the activity of co-transfected thyroglobulin and thyroperoxidase promoters.
Thyroid transcription factor I (TTF-1) plays a critical role in thyroid organogenesis and in the control of expression of several thyroid-specific genes, like those coding for thyroglobulin and thyroperoxidase. We have expressed the isolated DNA-binding homeodomain of TTF-1 in cultured thyroid cells by transient transfection. A specific reduction in the activity of co-transfected thyroglobulin and thyroperoxidase promoters was observed in the presence of the isolated TTF-1 homeodomain, as compared to their activity measured in the presence of a mutated homeodomain unable to bind DNA. The activity of the SV40 early promoter, used as a control, was only marginally affected in these experiments. The transactivation-deficient form of TTF-1 described here may thus be used for investigating other cellular processes that are dependent on TTF-1 transcriptional activity.
Christophe-Hobertus
C
C
I.R.I.B.H.N., Université Libre de Bruxelles, Faculté de Médecine, Belgium.
van Renterghem
P
P
Pichon
B
B
Christophe
D
D
D002460:Cell Line; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010544:Peroxidases / Q000235:genetics*; D011401:Promoter Regions, Genetic; D013954:Thyroglobulin / Q000235:genetics*; D013961:Thyroid Gland / Q000166:cytology / Q000201:enzymology; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D014162:Transfection
D009687:Nuclear Proteins; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors; D013954:Thyroglobulin; D010544:Peroxidases