Project description:It is known that, in addition to known allergens, other proteins in pollen can aid the development of an immune response in allergenic individuals. The contribution of the “unknown” protein allergens becomes especially prominent in phylogenetically related species where, despite of high homology of the lead allergens, the degree of allergenic potential can greatly vary. The aim of this study was to identify other potentially allergenic proteins in pollen of three common and very related allergenic tree species: birch (Betula pendula), hazel (Corylus avellana) and alder (Alnus glutinosa). For that purpose, we carried out a comprehensive, comparative proteomic screening of the pollen from the three species. In order to maximize protein recovery and coverage, different protein extraction and isolation strategies during sample preparation were employed. As a result, we report 2500 - 3000 identified proteins per each of the pollen species. Identified proteins were further used for a number of annotation steps, providing insight into differential distribution of peptidases, peptidase inhibitors and other potential allergenic proteins across the three species. Moreover, we carried out functional enrichment analysis that, interestingly, corroborated high species similarity in spite of their relatively distinct protein profiles. We provide to our knowledge first insight into proteomes of three very important allergenic pollen types, which is particularly vital for pollen of hazel and alder where not even transcriptomics data is available. Datasets provided in this study can be readily used as protein databases, and as such serve as an excellent starting point for further allergenic studies.