OLF-1-BINDING SITE - CHARACTERIZATION OF AN OLFACTORY NEURON-SPECIFICPROMOTER MOTIF

We report characterization of several domains within the 5' flanking r egion of the olfactory marker protein (OMP) gene that may participate in regulating transcription of this and other olfactory neuron-specifi c genes. Analysis by electrophoretic mobility shift assay and DNase I footprinting identifies two regions that contain a novel sequence moti f. Interactions between this motif and nuclear proteins were detected only with nuclear protein extracts derived from olfactory neuroepithel ium, and this activity is more abundant in olfactory epithelium enrich ed in immature neurons. We have designated a factor(s) involved in thi s binding as Olf-1. The Olf-1-binding motif consensus sequence was def ined as TCCCC(A/T)NGGAG. Studies with transgenic mice indicate that a 0.3-kb fragment of the OMP gene containing one Olf-1 motif is sufficie nt for olfactory tissue-specific expression of the reporter gene. Some of the other identified sequence motifs also interact specifically wi th olfactory nuclear protein extracts. We propose that Olf-1 is a nove l, olfactory neuron-specific trans-acting factor involved in the cell- specific expression of OMP.