cDNA cloning and expression of Cry j II the second major allergen of Japanese cedar pollen.

We have isolated and sequenced a cDNA clone coding for Cry j II, the second major allergen of Japanese cedar (Cryptomeria japonica) pollen. A 1.7-kilobase cDNA clone contained an open reading frame coding for a 514-amino acid protein, including a putative signal peptide of 54 amino acid and three potential glycosylation sites. The deduced amino acid sequence of the Cry j II shows significant identities to those of the polygalacturonases associated with fruit-ripening in tomato (40%) and avocado (43%) and found in pollen of maize (34%). Cry j II cDNA product expressed in E. coli was recognized by human IgE from patients suffering from cedar pollinosis, suggesting that recombinant Cry j II might be used as an allergen for the clinical diagnosis of cedar pollinosis.