El polifosfat és un element clau durant la replicació del DNA.

Autor/a

Bru Rullo, Samuel

Director/a

Clotet Erra, Josep

Fecha de defensa

2015-07-20

Depósito Legal

B-27516-2015

Páginas

175 p.



Departamento/Instituto

Universitat Internacional de Catalunya. Departament de Ciències Bàsiques

Resumen

Throughout its lifespan, eukaryotic cells steadily consume free cytoplasmic orthophosphate to produce phospholipids and mRNA. However, during DNA synthesis, in a matter of minutes, cells require large amount of phosphate molecules to be incorporated in dNTPs. It is not known whether this high consumption produces a sharp variation in cellular orthophosphate levels, or alternatively, a homeostatic system exists to prevent any variation. Polyphosphate (polyP) is a linear chain made of hundreds of Pi residues present in all living organisms, with a still unclear molecular function. In the present study we show that degradation of polyP is cell cycle regulated and, also, an important process to sustain the synthesis of dNTPs in S. cerevisiae. Mutants that cannot synthesise polyP (vtc4) or cannot hydrolyse it (ppn1 ppx1) present a lower rate of dNTP synthesis and it takes longer time to duplicate DNA. Recovery after UV stress also requires high levels of dNTPs, and here we show that mutants bearing low levels of polyP are more sensitive to UV, while cells overexpressing VTC4 are more resistant. Finally, we demonstrate that human dermal fibroblasts with reduced levels of polyP are also more sensitive to UV damage, suggesting that the protective role of polyP against UV damage might be conserved. In conclusion, this work identifies a new and important player during the synthesis of the building blocks of DNA.

Palabras clave

Cicle cel·lular; Ciclo celular; Cell cycle; Dany a DNA; Daño a DNA; DNA damage; dNTPs; Polifosfat; Polifosfato; Polyphosphate; S. cerevisiae

Materias

577 - Bioquímica. Biología molecular. Biofísica

Área de conocimiento

Biologia

Documentos

Tesi_Samuel_Bru_Rullo.pdf

1.959Mb

 

Derechos

L'accés als continguts d'aquesta tesi queda condicionat a l'acceptació de les condicions d'ús establertes per la següent llicència Creative Commons: http://creativecommons.org/licenses/by-nc-nd/3.0/es/
L'accés als continguts d'aquesta tesi queda condicionat a l'acceptació de les condicions d'ús establertes per la següent llicència Creative Commons: http://creativecommons.org/licenses/by-nc-nd/3.0/es/

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