Proteomska analiza uloge mistranslacije izoleucina u prilagodbi bakterije Escherichia coli na oksidacijski stres

master's thesis

• Title (english): Proteomic analysis of the role of isoleucine mistranslation in the adaptation of Escherichia coli to oxidative stress
• Author: Mateo Šerić
• Mentor: Jasmina Rokov Plavec (mentor)
• Mentor: Marko Močibob (mentor)
• Committee member: Jasmina Rokov Plavec (predsjednik povjerenstva)
• Committee member: Željka Car (član povjerenstva)
• Committee member: Ivana Kekez (član povjerenstva)
• Committee member: Morana Dulić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2025-02-25, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

Točan prijenos genetičke informacije važan je za normalan rad bioloških sustava. Aminoacil- tRNA-sintetaze ključni su enzimi u prevođenju genetskog koda jer spajaju molekule tRNA s pripadnim aminokiselinama. Iako se ugradnja pogrešnih aminokiselina u proteine veže uz negativne posljedice, stanice od ovog procesa mogu imati pozitivne učinke, poput otpornosti na stresne uvjete. Soj bakterije Escherichia coli koji eksprimira izolecil-tRNA-sintetazu s nefunkcionalnom domenom za popravak pogreške... More uzgajan je u mistranslatirajućim uvjetima, te je uočena prilagodba stanica na oksidacijski stres. Radi identifikacije procesa koji omogućuju ovu prilagodbu, izvršena je proteomska analiza. U stacionarnoj fazi utvrđeno je da mistranslacija na izoleucinskim položajima uzrokuje povećanu ekspresiju šaperona, proteaza te proteina koji sudjeluju u unosu peptida. Također, dolazi do smanjene ekspresije proteina koji sudjeluju u biosintezi enterobaktina, siderofora koji omogućuje transport željeza. Uočeno je i da dolazi do promjene u ekspresiji proteina koji sudjeluju u metabolizmu nekih aminokiselina. Dodatno, primijećena je pojačana ekspresija proteina RecA i smanjena ekspesija represora LexA, što upućuje da se aktivira SOS odgovor. Daljnja istraživanja pokazat će koji od ovih procesa su ključni za prilagodbu na oksidacijski stres uslijed mistranslacije. Less

Abstract (english)

Maintaining the accurate flow of genetic information is crucial for the normal function of all biological systems. Aminoacyl-tRNA synthetases are key enzymes in translating the genetic code, as they attach tRNA molecules to their cognate amino acids. Although incorporation of incorrect amino acids into proteins is generally associated with negative consequences, cells can sometimes benefit from this process, such as adaptation to stress. A strain of Escherichia coli expressing an... More isoleucyl-tRNA synthetase with a nonfunctional editing domain was cultivated under various mistranslating conditions and adaptation to oxidative stress was observed. To identify biological processes responsible for this adaptation, a proteomic analysis was performed. Analysis of proteome in stationary phase revealed that mistranslation at isoleucine positions leads to increased expression of chaperones, proteases and proteins involved in peptide uptake processes. Additionally, a decrease in the expression proteins involved in biosynthesis of enterobactin, siderophore involved in iron transport. Changes in the expression of proteins that are involved in the metabolism of amino acids were found. Also, the upregulation of RecA and downregulation of LexA expression suggests activation of SOS response. Further research will point out which of these processes are key to adaptation to oxidative stress due to mistranslation. Less

• Keywords: izoleucil-tRNA-sintetaza; mistranslacija; norvalin; oksidacijski stres; spektrometrija masa; valin
• Keywords (english): isoleucyl-tRNA synthetase; mass spectrometry; mistranslation; norvaline; oxidative stress; valine
• Language: croatian
• URN:NBN: urn:nbn:hr:217:868059
• Study programme: Title: Graduate university studies in chemistry; specializations in: Graduate university studies in chemistry; Course: Graduate university studies in chemistry; Study programme type: university; Study level: graduate; Academic / professional title: sveučilišni/a magistar/magistra kemije (sveučilišni/a magistar/magistra kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2025-03-19 12:33:10