Fatima Ferreira

Profilin: A Novel Pan-Allergen and Actin-Binding Protein in Plants

Using serum-IgE from a pollen-allergic patient we isolated a cDNA from a birch pollen expression library (Valenta et al., 1991a). The deduced amino acid sequence of this cDNA clone showed significant homology with sequences from other eukaryotic profilins. Profilins function as actin-binding proteins (Isenberg et al., 1980) and interact with phosphatidylinositol 4,5 bisphosphate (PIP2) (Goldschmidt-Clermont et al., 1990). In addition a role of profilins in the signal transduction cascade via CAP was proposed (Vojtek et al., 1991). These data indicate that profilins are essential components of eukaryotic cells. This chapter concerning the biological functions of plant profilins illustrates that these proteins are ubiquitously distributed in plants and are structurally similar. For this reason plant profilins can function as targets for cross-reactive IgE antibodies of allergic patients and represent a novel class of pan-allergens.