Proline Rich Protein 3 (PROL3)

By PCR of human submaxillary gland cDNA, Isemura and Saitoh (1994) cloned SMR3B, which they called PBII. SMR3B consists of 22-amino acid secretory signal sequence, cleavage of which results in a mature 57-amino acid protein. Southern blot analysis detected expression in human submaxillary gland, and Southern blot and database analysis indicated that SMR3B was conserved in vertebrates and yeast. Isemura (2000) reported a corrected SMR3B sequence. The author noted that SMR3B is also expressed in human parotid gland.Isemura (2000) determined that the SMR3B gene contains 3 exons spanning 7.1 kb. The first exon is noncoding, and the third exon encodes the entire mature protein sequence.