dc.contributor
Universitat Internacional de Catalunya. Departament de Ciències Bàsiques
dc.contributor.author
Bru Rullo, Samuel
dc.date.accessioned
2015-11-06T12:03:35Z
dc.date.available
2015-11-06T12:03:35Z
dc.date.issued
2015-07-20
dc.identifier.uri
http://hdl.handle.net/10803/317386
dc.description.abstract
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.
eng
dc.format.mimetype
application/pdf
dc.publisher
Universitat Internacional de Catalunya
dc.rights.license
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/
dc.rights.uri
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
*
dc.source
TDX (Tesis Doctorals en Xarxa)
dc.subject
Cicle cel·lular
dc.subject.other
Biologia
dc.title
El polifosfat és un element clau durant la replicació del DNA.
dc.type
info:eu-repo/semantics/doctoralThesis
dc.type
info:eu-repo/semantics/publishedVersion
dc.contributor.director
Clotet Erra, Josep
dc.rights.accessLevel
info:eu-repo/semantics/openAccess
dc.identifier.dl
B-27516-2015