Identification and characterization of a third gastrin response element (GAS-RE3) in the human histidine decarboxylase gene promoter.
In human gastric cancer cells the human histidine decarboxylase gene is regulated by gastrin through two overlapping cis-acting elements known as gastrin response elements 1&2 (GAS-RE1, GAS-RE2) [J. Biol. Chem. 274 (1999) 20961]. Here, we report the identification and characterization of a third element GAS-RE3 that was localized to a region +28 to +48 downstream of the transcriptional start site (+1). Gastrin stimulation induced a rapid increase in binding to the element of a novel nuclear factor named gastrin response element-binding protein 3 (GAS-REBP3). Block mutations in the GAS-RE3 sequence (+38GTGCG(+42) to +38TAAGT(+42)) led to reduced promoter activity and decreased binding in EMSA. UV cross-linking studies and Southwestern blot analysis with wildtype and mutant GAS-RE3 showed that GAS-REBP3 was a approximately 110kDa protein. Thus, gastrin-mediated regulation of HDC gene expression appears to be mediated by a complex cis-acting element, which binds at least three distinct nuclear factors.
Raychowdhury
Raktima
R
Harvard Medical School and Gastrointestinal Unit, Massachusetts General Hospital, Boston, MA 02114, USA.
Fleming
John V
JV
McLaughlin
John T
JT
Bulitta
Clemens J
CJ
Wang
Timothy C
TC
D001483:Base Sequence; D001665:Binding Sites; D015139:Blotting, Southern; D015153:Blotting, Western; D003432:Cross-Linking Reagents / Q000494:pharmacology; D005755:Gastrins / Q000235:genetics* / Q000378:metabolism; D017930:Genes, Reporter; D006640:Histidine Decarboxylase / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D009841:Oligonucleotides / Q000235:genetics; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D020218:Response Elements; D014162:Transfection; D014466:Ultraviolet Rays
D003432:Cross-Linking Reagents; D005755:Gastrins; D009841:Oligonucleotides; D006640:Histidine Decarboxylase