Two preproendothelin 1 mRNAs transcribed by alternative promoters.
Endothelin-1, initially identified as potent vasoconstrictor secreted by vascular endothelial cells, was subsequently found to have many effects on both vascular and nonvascular tissues. We have identified from a human placenta cDNA library a clone (cDNA-2) which corresponds to a novel 5'-extended preproendothelin 1 (preproET-1) mRNA. Comparison with the known preproET-1 mRNA (cDNA-1), showed that the two molecules share the same coding sequence but differ in the 5'-untranslated region. Interestingly, cDNA-2 extends upstream of promoter regions previously shown to be essential for full preproET-1 expression. Primer extension and PCR analysis of human placenta RNA demonstrated the presence of additional transcription initiation sites located upstream of the previously identified preproET-1 CAP site. Moreover, the two mRNAs show different pattern of expression. To elucidate the mechanisms controlling the production of alternative transcripts we transfected COS-1 cells with a series of preproET-1 promoter deletion mutants. This analysis revealed that the human preproET-1 gene can be transcribed from a proximal and a distal promoter element which has hitherto been undetected. In addition, we demonstrate the presence of a region in the down-epithelial specific expression.
Benatti
L
L
Department of Biotechnology, Farmitalia Carlo Erba, Nerviano, Italy.
Bonecchi
L
L
Cozzi
L
L
Sarmientos
P
P
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D019332:Endothelin-1; D016232:Endothelins / Q000235:genetics*; D005260:Female; D015723:Gene Library; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D010920:Placenta / Q000502:physiology; D011247:Pregnancy; D011401:Promoter Regions, Genetic; D011498:Protein Precursors / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D017384:Sequence Deletion; D014158:Transcription, Genetic; D014162:Transfection
D019332:Endothelin-1; D016232:Endothelins; D009838:Oligodeoxyribonucleotides; D011498:Protein Precursors; D012333:RNA, Messenger; D011994:Recombinant Proteins; D004247:DNA; D015500:Chloramphenicol O-Acetyltransferase