The protein Alt a 1 (ALTA1) is a major allergen found in the fungus Alternaria alternata. Alt a 1 is known to be a unique β-barrel protein dimer found exclusively in fungi [1]. It is detected in the spores of A. alternata before germination [2][3]. Alt a 1 is a species-specific allergen with no known cross-reactivity with other allergens [4]. It is the major allergen of A. alternata and can be found in the cell wall of its spores [5]. Alt a 1 is the major fungal allergen responsible for chronic asthma, and it has been the subject of allergen-specific immunotherapy trials, demonstrating efficacy and safety [6][7]. Alt a 1 has also been identified as interacting with PR5 thaumatin-like proteins [3]. However, little is known about its immunological activity [8]. Although Alt a 1 is a key target, its exact function is yet to be explored [9].
References:
[1] M. Chruszcz, M. Chapman, T. Osinski, R. Solberg, M. Demas, P. Porebskiet al., "Alternaria alternata allergen alt a 1: a unique β-barrel protein dimer found exclusively in fungi", Journal of Allergy and Clinical Immunology, vol. 130, no. 1, p. 241-247.e9, 2012. https://doi.org/10.1016/j.jaci.2012.03.047
[2] M. Garrido-Arandia, J. Silva-Navas, C. Ramírez-Castillejo, N. Cubells-Baeza, C. Gomez-Casado, D. Barberet al., "Characterisation of a flavonoid ligand of the fungal protein alt a 1", Scientific Reports, vol. 6, no. 1, 2016. https://doi.org/10.1038/srep33468
[3] C. Gómez‐Casado, A. Murua‐García, M. Garrido‐Arandia, P. González‐Melendi, R. Sánchez‐Monge, D. Barberet al., "Alt a 1 from alternaria interacts with pr5 thaumatin‐like proteins", Febs Letters, vol. 588, no. 9, p. 1501-1508, 2014. https://doi.org/10.1016/j.febslet.2014.02.044
[4] T. Hayes, A. Rumore, B. Howard, X. He, M. Luo, S. Wuenschmannet al., "Innate immunity induced by the major allergen alt a 1 from the fungus alternaria is dependent upon toll-like receptors 2/4 in human lung epithelial cells", Frontiers in Immunology, vol. 9, 2018. https://doi.org/10.3389/fimmu.2018.01507
[5] G. Wagner, S. Gutfreund, K. Fauland, W. Keller, R. Valenta, & K. Zangger, "Backbone resonance assignment of alt a 1, a unique β-barrel protein and the major allergen of alternaria alternata", Biomolecular NMR Assignments, vol. 8, no. 2, p. 229-231, 2013. https://doi.org/10.1007/s12104-013-9489-z
[6] A. Tabar, L. Prieto, P. Alba, A. Nieto, M. Rodríguez, M. Torrecillaset al., "Double-blind, randomized, placebo-controlled trial of allergen-specific immunotherapy with the major allergen alt a 1", Journal of Allergy and Clinical Immunology, vol. 144, no. 1, p. 216-223.e3, 2019. https://doi.org/10.1016/j.jaci.2019.02.029
[7] D. Rodríguez, A. Tabar, M. Castillo, M. Martínez-Gomariz, I. Dobski, & R. Palacios, "Changes in the sensitization pattern to alternaria alternata allergens in patients treated with alt a 1 immunotherapy", Journal of Fungi, vol. 7, no. 11, p. 974, 2021. https://doi.org/10.3390/jof7110974
[8] M. Garrido-Arandia, J. Tome-Amat, D. Pazos-Castro, V. Esteban, M. Escribese, G. Hernandez-Ramirezet al., "Interaction of alt a 1 with slc22a17 in the airway mucosa", Allergy, vol. 74, no. 11, p. 2167-2180, 2019. https://doi.org/10.1111/all.13877
[9] J. Madhumathi, P. Prince, D. Rao, A. Karande, M. Reddy, & P. Kaliraj, "Epitope mapping ofbrugia malayialt-2 and the development of a multi-epitope vaccine for lymphatic filariasis", Journal of Helminthology, vol. 91, no. 1, p. 43-54, 2016. https://doi.org/10.1017/s0022149x16000055