Differential display identification of plunc, a novel gene expressed in embryonic palate, nasal epithelium, and adult lung

We have identified a novel gene transcript of approximately 1.1 kilobases i n length that is expressed in the presumptive nasal epithelium of the mouse embryo. In situ hybridization analysis shows discrete regions of expressio n associated with the palate, nasal septum, and nasal conchae, This transcr ipt is also expressed strongly in the trachea and bronchi of the adult lung , Screening of a mouse heart cDNA library yielded several overlapping clone s to give a continuous sequence of 1113 bases, containing an open reading f rame of 278 codons comprising the complete mRNA. No significant homologies with known genes were observed at the nucleotide level; limited amino acid homology with two salivary gland-specific proteins was noted. A search for functionally significant protein motifs revealed consensus sequences for N- glycosylation, protein kinase C and casein kinase phosphorylation, and a le ucine zipper. Additionally, we observed a unique amino acid sequence patter n, consisting of the residues Gly-(Leu/Pro/Gln)-(Pro/Leu)-Leu-Pro-Leu, repe ated four times near the amino-terminal portion of the protein with two ami no acid residues separating the repeats. Based on these observations, we pr opose that we have identified a new gene, which we call plunc (for palate, lung, and nasal epithelium clone; GenBank(TM) accession number U69172).