Estudio de acuaporinas vegetales pertenecientes a la familia PIP : análisis de las relaciones estructura-función de homo-tetrámeros y tetrámeros mixtos PIP1-PIP2

In the present Thesis we evaluated the capacity of plant aquaporins belonging to the PIP subfamily to assembly as hetero-tetramers. With this aim, we investigated the functional properties of two aquaporins belonging to the PIP2 group regarding their interaction with PIP1. Our results show that it i...

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Autor principal: Jozefkowicz, Cintia
Otros Autores: Alleva, Karina
Formato: Tesis doctoral acceptedVersion
Lenguaje:Español
Publicado: Facultad de Farmacia y Bioquímica 2016
Materias:
PIP
Acceso en línea:http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=posgraafa&cl=CL1&d=HWA_1175
http://repositoriouba.sisbi.uba.ar/gsdl/collect/posgraafa/index/assoc/HWA_1175.dir/1175.PDF
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Sumario:In the present Thesis we evaluated the capacity of plant aquaporins belonging to the PIP subfamily to assembly as hetero-tetramers. With this aim, we investigated the functional properties of two aquaporins belonging to the PIP2 group regarding their interaction with PIP1. Our results show that it is not correct to generalize that all PIP2 are able to interact with all PIP1, as we proved that the interaction between PIP1 and PIP2 is dependent on specific pairs of PIP1 and PIP2 proteins. We identify the first extracellular loop of PIP2 as a key structural element in the interaction between monomers in the tetramer and also as a possible controller of the hetero-tetramerization phenomenon. We also probed that the hetero-tetramerization between PIP1-PIP2 do not have a stoichiometric constrain and depends on the relative quantities of PIP1 and PIP2 monomers which are co-expressed in the cell. Moreover, hetero-tetramers with all the possible stiochiometries present equal biological activity in terms of water transport and pH intracellular regulation, being these functional properties different from the ones observed for homo-tetramers. In summary, this work shed light on the hetero-tetramerization of PIP channels as a new relevant mechanism to adjust plasma membrane water transport of plant cells.