The human luteinizing hormone receptor gene promoter: Activation by Sp1 and Sp3 and inhibitory regulation

To understand the transcriptional mechanism(s) of human LH receptor (LHR) g ene expression, we have identified the dominant functional cis-elements tha t regulate the activity of the promoter domain (-1 to -176 bp from ATG). Mu tagenesis demonstrated that the promoter activity was dependent on two Spl domains (-79 bp, -120 bp) in a transformed normal placental cell (PLC) and the choriocarcinoma JAR cell. Both elements interacted with endogenous Spl and Sp3 factors but not with Sp2 or Sp4. In Drosophila SL2 cells, the promo ter was activated by either Spl or Sp3. An ERE half-site (EREhs) at -174 bp was inhibitory (by 100%), but was unresponsive to estradiol and did not bi nd the estrogen receptor or orphan receptors ERR1 and SF-1. The 5 ' upstrea m sequence (-177 to -2056 bp) inhibited promoter activity in PLC by 60%, bu t only minimally in JAR cells. Activation of the human LHR promoter through Sp1/3 factors is negatively regulated through EREhs and upstream sequences to exert control of gene expression. (C) 1999 Academic Press.