Cloning and characterization of the 5 '-flanking region of the human growth hormone secretagogue receptor gene

Recently, the growth hormone secretagogue receptor (GHS-R) cDNA has been is olated from the pituitary and hypothalamus, To evaluate the regulation of h uman (h) GHS-R gene expression, we cloned the hGHS-R gene containing the 5' -flanking region of 0.6-2.9 kilobase pairs. Analysis of the hGHS-R transcri pts with 5'-rapid amplification of cDNA ends suggested that the putative tr anscription initiation site was approximately - 453 base pairs upstream of the translation initiation site (+1). There is no typical TATA, CAAT, or GC box but an initiator-like sequence and putative binding sites for several transcription factors around the putative transcription start site. The S'- flanking region inserted into a luciferase reporter vector had promoter act ivity in GH, cells but had activity indistinguishable from background in He La or EP1 cells. The hGHS-R promoter activity in GH, cells increased by del etion of nucleotides from - 1224 to -734, whereas it was decreased by furth er deletion from -734 to -608. Knowledge of the promoter region of the hGHS -R gene will facilitate elucidation of its transcriptional control.