Complete nucleotide sequence of human vasoactive intestinal peptide/PHM-27 gene and its inducible promoter

We have previously shown that the VIP precursor contains a novel PHI-27-like peptide, PHM-27, and that the synthesis of the prepro-VIP/PHM-27 mRNA is induced with cAMP and TPA in human neuroblastoma cells. In this study, we have determined the complete nucleotide sequence of the human VIP/PHM-27 gene. The gene spans 8,837 bp and consists of seven exons and six introns. Exon I of 165 bp consists of the 5' untranslated region of the gene, exon II of 117 bp encodes the signal peptide of prepro-VIP/PHM-27, exon III of 123 bp encodes the amino-terminal region, exon IV of 105 bp encodes PHM-27, exon V of 132 bp encodes VIP, exon VI of 89 bp contains the termination codon of the prepro-VIP/PHM-27 mRNA, and exon VII of 724 bp consists of the 3' untranslated region of the gene. VIP and its structurally related peptide, PHM-27, were encoded in different exons V and IV, and the sequences around the splice junctions between these exons and their adjacent introns were highly conserved, suggesting that the VIP-encoding and PHM-27-encoding exons have been duplicated from an ancestral exon over a broad area containing its adjacent introns. We also determined the 1,929-bp sequence of the 5' flanking region of the human VIP/PHM-27 gene and found that four TATA-box sequences were present at 28 bp, 145 bp, 772 bp, and 900 bp upstream of the cap site. Primer extension, exon mapping, and mung bean nuclease mapping analyses revealed that only the TATA-box sequence 28 bp upstream of the cap site was the promoter that is inducible by cAMP and TPA in the human neuroblastoma cells. An 18-bp sequence 52 bp upstream from the TATA-box sequence was suggested to be a cAMP/phorbol esters-responsive element of the human VIP/PHM-27 gene.