SEQUENCE-ANALYSIS OF THE PROMOTER REGION OF THE RAT SOMATOSTATIN RECEPTOR SUBTYPE-1 GENE

Somatostatin receptor (SSTR) subtype genes are differentially expresse d in brain and various peripheral tissues. RNA blotting and semiquanti tative PCR analyses have revealed low levels of SSTR1 mRNA in the gast rointestinal tract and relatively high levels in GH(3) anterior pituit ary cells. As a first step in the investigation of the regulation of S STR1 gene expression, we isolated a genomic fragment that contains the promoter region and determined the transcriptional initiation site. T he SSTR1 gene lacks introns and TATA and CAAT motifs, but possesses se veral consensus recognition sequences for the transcription factors GC F and AP-2. The presence, also, of two Pit-1 binding sites could expla in the high SSTR1 mRNA levels in GH(3) cells.