Physical interaction between the strawberry allergen Fra a 1 and an associated partner FaAP: Interaction of Fra a 1 proteins and FaAP

• Published in: Proteins, structure, function, and bioinformatics structure, function, and bioinformatics, 2017-10, Vol.85 (10), p.1891-1901
• Main Authors: Franz‐Oberdorf, Katrin, Langer, Andreas, Strasser, Ralf, Isono, Erika, Ranftl, Quirin L., Wunschel, Christian, Schwab, Wilfried
• Format: Article
• Language: English
• Subjects: abscisic acid (ABA); allergen; Allergens; Allergies; Amino Acid Sequence - genetics; Antigens, Plant - chemistry; Antigens, Plant - genetics; Antigens, Plant - metabolism; Bet v 1 antigen; Binding; Deoxyribonucleic acid; dimerization; DNA; Fra a 1‐Associated Protein (FaAP); Fragaria - chemistry; Homology; Humans; Mal d 1 antigen; Pathogenesis; Physiology; plant defense; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - metabolism; Pollen; Protein Binding; Protein Interaction Maps - genetics; Proteins; protein–protein interaction; PR‐10 protein family; strawberry allergen Fra a 1.01E/1.02/1.03; Switching; time resolved DNA‐switching measurements; Yeast; yeast two‐hybrid
• ISSN: 0887-3585; 1097-0134
• DOI: 10.1002/prot.25343

The strawberry fruit allergens Fra a 1.01E, Fra a 1.02 and Fra a 1.03 belong to the group of pathogenesis‐related 10 (PR‐10) proteins and are homologs of the major birch pollen Bet v 1 and apple allergen Mal d 1. Bet v 1 related proteins are the most extensively studied allergens but their physiological function in planta remains elusive. Since Mal d 1‐Associated Protein has been previously identified as interaction partner of Mal d 1 we studied the binding of the orthologous Fra a 1‐Associated Protein (FaAP) to Fra a 1.01E/1.02/1.03. As the C‐terminal sequence of FaAP showed strong auto‐activation activity in yeast 2‐hybrid analysis a novel time resolved DNA‐switching system was successfully applied. Fra a 1.01E, Fra a 1.02, and Fra a 1.03 bind to FaAP with KD of 4.5 ± 1.1, 15 ± 3, and 11 ± 2 nM, respectively. Fra a 1.01E forms a dimer, whereas Fra a 1.02 and Fra a 1.03 bind as monomer. The results imply that PR‐10 proteins might be integrated into a protein‐interaction network and FaAP binding appears to be essential for the physiological function of the Fra a 1 proteins.