Control by thyroid hormone of NGFI-A gene expression in lung: regulation of NGFI-A promoter activity.
In previous studies, it was shown that the expression of the transcription factor NGFI-A is under thyroid hormone (T3) control in developing rat brain. Here, the effect of this hormone on the expression of this gene in lung, as well as the effect of T3 and NGFI-A protein on NGFI-A promoter activity, has been investigated. The results show that T3 regulates NGFI-A gene expression at a pretranslational level in neonatal and adult rat lung, but also at a translational and/or posttranslational level in 5-day-old neonates, since the NGFI-A protein content was decreased in hypothyroid animals without changes in mRNA. Transfection experiments showed an induction of NGFI-A promoter activity by thyroid hormone. NGFI-A protein blocked this stimulation, suggesting a negative interaction between NGFI-A protein and thyroid hormone receptor, which could explain the transient induction by T3 of this gene observed in the first 2-4 h.
Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense de Madrid, Spain.
J C
JC
Rodríguez-Manzaneque
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A
Pérez-Castillo
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A
Santos
D000367:Age Factors; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D019556:COS Cells; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D051766:Early Growth Response Protein 1; D005786:Gene Expression Regulation; D007037:Hypothyroidism / Q000235:genetics; D017874:Immediate-Early Proteins; D008168:Lung / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D018168:Receptors, Retinoic Acid / Q000235:genetics; D011988:Receptors, Thyroid Hormone / Q000235:genetics; D047488:Retinoid X Receptors; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D015533:Transcriptional Activation; D014162:Transfection; D014284:Triiodothyronine / Q000494:pharmacology*
D004268:DNA-Binding Proteins; D051766:Early Growth Response Protein 1; C486110:Egr1 protein, rat; D017874:Immediate-Early Proteins; D012333:RNA, Messenger; D018168:Receptors, Retinoic Acid; D011988:Receptors, Thyroid Hormone; D047488:Retinoid X Receptors; D014157:Transcription Factors; D014284:Triiodothyronine