Activation of the NPTA element of the CYP2A3 gene by NFI-A2, a nasal mucosa-selective nuclear factor 1 isoform

The aim of this study was to determine whether the NPTA element of the olfactory mucosa-predominant CYP2A3 gene can be activated by NFI-A2, a recently identified member of the nuclear factor 1 family of transcription factors. Isoform-specific RNA-PCR confirmed that NFI-A2 is mainly expressed in rat olfactory mucosa. A full-length NFI-A2 cDNA was isolated from a cDNA library of rat olfactory mucosa and was used for preparation of a construct encoding a fusion protein of NFI-A2 with the yeast GAL4 activation domain. Expression of the fusion protein in yeast was detected with an antibody to NFI-A. The fusion protein activated the expression of a LacZ reporter gene in yeast one-hybrid assays with a reporter construct containing the NPTA element, but not with other constructs lacking the NPTA element. These findings suggest that NFI-A2 may be involved in the tissue-selective transcriptional activation of the CYP2A3 gene in the olfactory mucosa.