HIGH CONSERVATION OF UPSTREAM REGULATORY SEQUENCES ON THE HUMAN AND MOUSE VASOACTIVE-INTESTINAL-PEPTIDE (VIP) GENES

The neuropeptide vasoactive intestinal peptide (VIP) gene is subject to complex transcriptional regulation resulting in expression of the encoded peptides in distinct subpopulations of neurons in most structures of the nervous system, and tissue-specific changes in expression in response to a variety of hormone and environmental factors. This diverse regulation allows the encoded peptides to carry out putative neurotransmitter, neuromodulator, trophic, neuroendocrine, and immune functions. Despite the potential significance of the processes governing its expression, only the human gene has been studied in any depth, and only a single regulatory element has been identified, a cAMP-responsive sequence less than 100 bp upstream from the transcriptional start site. Because tissue-specific patterns of VIP expression are remarkably well conserved between rodents and humans, we isolated the mouse VIP gene and compared 5' flanking sequences with that of the human gene to identify homologous regions which might be involved in regulation common to both species. Of significant interest is a 210 bp region located more than 1.1 kb upstream from the transcription start site that is 91% conserved between the two species. Of addi- tional interest is a 34 bp perfect dCA.dTC repeat present only on the mouse gene which may be capable of forming Z-DNA.