Characterization of an alternative promoter in the human growth hormone gene.
Transcription of the human growth hormone (hGH) gene depends on cis-acting elements contained within 300 base pairs of its 5'-flanking sequence. An earlier in vitro study of the transcriptional activity of this 5'-flanking region suggested that transcription can start upstream from position +1. We have investigated this phenomenon by cell-free transcription and transient transfection of chimeric constructs in cultured pituitary cells and in HeLa cells and by analysis of RNA from human pituitary glands and HeLa cells. Transcription initiation sites were identified at positions -54 and -197 by cell-free transcription assays and by RNAse mapping of human pituitary RNA. In transfection assays, the hGH gene 5'-flanking sequence upstream from position -197 displayed transcriptional activity, which critically depended on the upstream stimulatory factor-binding site located between positions -253 and -266. Transcripts initiated upstream from position +1 were detected in human pituitary RNA by polymerase chain reaction amplification and Northern blotting. These transcripts were longer than the mRNA encoding hGH. They might control initiation at position +1 or code for a novel peptide.
Courtois
S J
SJ
Hormone and Metabolic Research Unit, University of Louvain Medical School, Brussels, Belgium.
Lafontaine
D A
DA
Rousseau
G G
GG
D001483:Base Sequence; D005786:Gene Expression Regulation; D013006:Growth Hormone / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D010902:Pituitary Gland / Q000502:physiology; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D016385:TATA Box; D014158:Transcription, Genetic; D014162:Transfection
D012333:RNA, Messenger; D013006:Growth Hormone