Rk. Menon et al., CLONING OF THE PROMOTER-REGULATORY REGION OF THE MURINE GROWTH-HORMONE RECEPTOR GENE - IDENTIFICATION OF A DEVELOPMENTALLY-REGULATED ENHANCER ELEMENT, The Journal of biological chemistry, 270(15), 1995, pp. 8851-8859
The growth hormone (GH) receptor is essential for the actions of GH on
postnatal growth and metabolism. To identify DNA sequences involved i
n the regulation of transcription of the murine GH receptor gene, a 17
-kilobase genomic clone containing the 5'-flanking region, exon 1, and
part of intron 1 of the murine GH receptor gene was isolated. Utilizi
ng primer extension and ribonuclease protection assays, two major tran
scription start sites were identified in RNA from liver of male, femal
e, and pregnant mice. Transient transfection stud ies using a reporter
gene demonstrated promoter activity in a variety of eukaryotic cells.
Deletional analysis and DNA protein binding assays led to the identif
ication of a 30-base pair enhancer element located about 3.4 kilobases
upstream of the transcription start sites. Computer analysis of the n
ucleotide sequence of the enhancer element did not reveal any potentia
l DNA binding motifs for known transcription factors, and this DNA ele
ment failed to exhibit binding activity for some common transcription
factors. Analysis of both functional activity and DNA-protein binding
activity of this enhancer element in adult and fetal hepatocytes sugge
sts that this DNA element may play a role in the developmental express
ion of the GH receptor gene.