ANALYSIS OF THE PROMOTER OF THE LUTEINIZING HORMONE HUMAN CHORIONIC-GONADOTROPIN RECEPTOR GENE IN NEUROENDOCRINE CELLS/

We investigated the molecular basis of luteinizing hormone (LH)/human chorionic gonadotropin (hCG) receptor gene transcription in immortaliz ed alpha T3 gonadotropes, hypothalamic GT1-7 and hippocampal HN33p neu rons. Nuclear run-on transcription, as well as transfection assays wit h fusion constructs of luciferase and the 5'-flanking region of LH/hCG receptor gene, revealed that GT1-7 neurons transcribe more than the a lpha T3 or HN33p cells. Transient transfection of truncated reporter g ene constructs and gel mobility shift assays revealed that while all n euroendocrine cells use the same promoter, they contain different leve ls of promoter binding proteins. Higher levels of these proteins may e xplain increased transcription of the LH/hCG receptor gene in GT1-7 ne urons compared with alpha T3 and HN33p cells.