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Tesi etd-01152008-103458


Tipo di tesi
Tesi di dottorato di ricerca
Autore
DOBRI, NICOLETA
Indirizzo email
nicoletadobri@yahoo.com
URN
etd-01152008-103458
Titolo
Invecchiamento cellulare e riparazione del danno ossidativo nel ciliato Euplotes raikovi: caratterizzazione dei geni specifici per le metionina-solfossido redattasi
Settore scientifico disciplinare
BIO/05
Corso di studi
BIOLOGIA EVOLUZIONISTICA (PROTISTI, ANIMALI, UOMO, ECOLOGIA MARINA)
Commissione
Relatore Prof. Luporini, Pierangelo
Relatore Prof. Vallesi, Adriana
Parole chiave
  • stress ossidativo
  • ossidazione delle metionine
  • ossidazione dei feromoni
  • le metionina-solfossido redattasi
  • invecchiamento cellulare
Data inizio appello
11/01/2008;
Disponibilità
parziale
Data di rilascio
2048-01-11
Riassunto analitico
Ciliated protozoa represent excellent material to explore the biology of ageing and rejuvenation, since they are both “complex” organisms and “simple” cells directly exposed at the environment and natural selection. Using Euplotes raikovi (a protistan whose life cycle is well characterized), I investigated the molecular resources that enable cells to repair oxidative damage of their vital macromolecules. A complex of six distinct genes that encode two forms, A and B, of methionine sulphoxide redutase (Msr, the enzyme that reduces a residue of methionine sulphoxide to methionine) was identified. The complete structure of two of these genes (designated Er-msrB and Er-msrA/B) was determined including both coding and non-coding regions; the structural analysis of the other four genes (Er-msrA1, Er-msrA2-A, Er-msrA2-B, e Er-msrA2-C) was incomplete. Er-MsrB2 (specified by one of the two open reading frames of the Er-msrA/B gene), Er-MsrB1, and Er-MsrA1 are closely related to Msr’s of other protozoa. In contrast, Er-msrA3 (specified by the second open reading frame of the Er-msrA/B gene) and Er-MsrA2 are phylogenetically related to Msr’s of prokaryotic origin. A further divergence between the Er-msr genes was detected at the functional level. Transcription of the Er-msrB gene is apparently not induced by oxidative stress, whereas transcription of the genes encoding the Msr A forms is specifically enhanced in cells subjected to oxidative stress
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