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oai:riubu.ubu.es:10259/116692026-05-22T22:00:47Zcom_10259_2699col_10259_3887

Ayllón Barasoain, Juan 852 600 0000-0002-7556-8106 García Sastre, Adolfo 9de2ea8b-c019-414d-bb90-b1d51ef5bbd7 600 Aslam, Sadaf 34ce451c-1783-43a0-99fe-d911a3c31bcd 600 Universidad de Burgos. Departamento de Ciencias de la Salud 0f0f709b-56c1-4b66-850e-5c1254c71149 500 2026-05-20T09:43:52Z 2026-05-20T09:43:52Z 2025 2026-03-09 https://hdl.handle.net/10259/11669 10.36443/10259/11669 La proteína NS1 del virus de la gripe A desempeña múltiples funciones províricas en células infectadas. Esta proteína multifuncional interactúa con numerosos factores celulares, algunos de relevancia biológica aún poco definida, como su capacidad para unirse y activar las PI3K de clase IA. Las PI3K son quinasas lipídicas reguladas que actúan como nodos clave en redes de señalización celular. La activación de PI3K por NS1 se produce mediante su unión a la subunidad p85β, aunque la importancia de esta especificidad y la contribución de las isoformas de p110 siguen siendo desconocidas. Para estudiarlo, hemos desarrollado un ensayo BiFC que permite seguir heterodímeros específicos de PI3K. Nuestros resultados muestran que NS1 induce una relocalización y activación dependientes de la isoforma de los heterodímeros de PI3K. Además, mutaciones oncogénicas en ambas subunidades imitan el efecto de NS1 y rescatan parcialmente la pérdida de función en virus mutantes The non-structural protein 1 (NS1) of influenza A virus performs a broad variety of proviral activities in the infected cell, primarily mediating evasion from the host innate immune response by being the main viral interferon antagonist. However, among the multiple interactions described for this small multifunctional protein, there are several whose biological relevance remains obscure, such as the ability of NS1 to bind and activate class IA phosphoinositide 3kinases (PI3Ks). PI3Ks are highly regulated lipid kinases that act as critical nodes in multiple cell signaling networks and regulate cellular physiology, including differentiation, growth, survival, trafficking, and immune function. As such, PI3Ks are also important proto-oncogenes whose deregulation lies behind a substantial number of different human cancers. Structurally, class IA PI3Ks are heterodimers formed by a regulatory (p85) and catalytic (p110) subunit, of which there are several isoforms described, adding further layers of complexity to their activity. Activation of PI3K by NS1 is mediated by NS1 binding to the p85 subunit. Interestingly, such binding is specific to the p85β isoform, and PI3K heterodimers containing p85β and any of the other three p110 isoforms are presumably activated by NS1. However, the significance of this p85β specificity, and the contributions of different p110 isoforms, remains unknown. In order to better understand the consequences of PI3K activation by NS1, we have developed a bimolecular fluorescence complementation (BiFC) assay to selectively track the different PI3K heterodimers according to their specific regulatory and catalytic isoforms, as well as to assess their behavior upon activation. Using this system, we found that NS1 induces an isoform-specific relocation and activation of the different PI3K heterodimers. However, the effects of other known activators of PI3K, such as Ras and Src, were different from those induced by NS1. We found that clinically relevant, oncogenic hyper-activating mutations in both catalytic and regulatory subunits of PI3K could mimic the effect caused by NS1, and partially rescued the loss of viral fitness in a recombinant virus encoding a p85β-binding deficient NS1. We postulate that by mimicking an oncogenic deregulation of the PI3K pathway, influenza A virus induces a transient, transformed-like status in the infected cell to stimulate virus replication Programa de Doctorado en Ciencias de la Salud application/pdf eng Attribution-NonCommercial-NoDerivatives 4.0 Internacional http://creativecommons.org/licenses/by-nc-nd/4.0/ Este documento está sujeto a una licencia de uso Creative Commons, por la cual está permitido hacer copia, distribuir y comunicar públicamente la obra siempre que se cite al autor original y no se haga de él uso comercial ni obra derivada info:eu-repo/semantics/openAccess Virus de la gripe A Proteína no estructural 1 (NS1) Fosfatidilinositol-3-quinasa (PI3K) Complementación de fluorescencia bimolecular (BiFC) Oncogénesis Oncogenesis Influenza A virus Non-structural protein 1 (NS1) Phosphoinositide-3-kinase (PI3K) Bimolecular fluorescence complementation (BiFC) Enfermedades víricas Virus diseases 2420.08 Virus Respiratorios 2407 Biología Celular 2415 Biología Molecular 2415.01 Biología Molecular de Microorganismos Study of novel pro-viral activities of non-structural protein 1 (NS1) of influenza A virus info:eu-repo/semantics/doctoralThesis info:eu-repo/semantics/acceptedVersion THUMBNAIL Aslam_Sadaf-Tesis.pdf.jpg Aslam_Sadaf-Tesis.pdf.jpg IM Thumbnail image/jpeg 2253 https://riubu.ubu.es/bitstream/10259/11669/4/Aslam_Sadaf-Tesis.pdf.jpg d1f7b7f11a859a786c95a7266aa681cb MD5 4 LICENSE license.txt license.txt text/plain; charset=utf-8 1362 https://riubu.ubu.es/bitstream/10259/11669/3/license.txt 5d013bfa6e473ff0db22cd82a4d71a70 MD5 3 CC-LICENSE license_rdf license_rdf application/rdf+xml; charset=utf-8 805 https://riubu.ubu.es/bitstream/10259/11669/2/license_rdf 4460e5956bc1d1639be9ae6146a50347 MD5 2 ORIGINAL Aslam_Sadaf-Tesis.pdf Aslam_Sadaf-Tesis.pdf application/pdf 103537581 https://riubu.ubu.es/bitstream/10259/11669/1/Aslam_Sadaf-Tesis.pdf 1fe239852d8183b70f70fa3c3a3fb652 MD5 1 10259/11669 oai:riubu.ubu.es:10259/11669 2026-05-23 00:00:47.752 Repositorio Institucional de la Universidad de Burgos bubrep@ubu.es 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