Major allergen Phl p Vb in timothy grass is a novel pollen RNase

• Published in: FEBS letters 1995-04, Vol.363 (1), p.6-12
• Main Authors: Bufe, A., Schramm, G., Keown, M.B., Schlaak, M., Becker, W.-M.
• Format: Article
• Language: English
• Subjects: Allergens; Amino Acid Sequence; Antibodies, Monoclonal; Base Sequence; Blotting, Western; cDNA; Chromatography, High Pressure Liquid; DNA, Complementary - chemistry; DNA, Complementary - isolation & purification; Electrophoresis, Polyacrylamide Gel; Major allergen; Molecular Sequence Data; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - metabolism; Pollen; Recombinant Proteins - chemistry; Recombinant Proteins - metabolism; Ribonucleases - metabolism; RNA, Messenger - metabolism; RNase activity; Salicylates - pharmacology; Salicylic Acid; Sequence Homology; Timothy grass pollen
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(95)00259-C

A cDNA coding for the major group V allergen Phl p Vb was isolated from a timothy grass pollen cDNA library by immunoscreening with a specific monoclonal antibody. It was discovered for the first time that the recombinant Phl p Vb pollen allergen after expression and purification has ribonuclease activity. High homology of Phl p Vb to other group V allergens in grass pollen indicates similar function. By RNase activity gel of natural pollen extract of timothy grass and consecutive Western blot analysis of the excised proteins, the RNase active bands were shown to be group V allergens. Additionally it was demonstrated that an homologous protein to Phl p Vb in the mother plant could be induced by salicylic acid. This indicates that group Vb allergens may be involved in host-pathogen interactions because in pollen they are quickly exported RNases and in the mother plant they depend on a hormone which is related to expression of plant resistance genes.