Utjecaj katalitičkih aktivnosti podjedinice RNA egzosoma Dis3 na vijabilnost stanica i stabilnost stanične stijenke kvasca Saccharomyces cerevisiae

undergraduate thesis

• Title (english): Influence of catalytic activities of RNA exosome subunit Dis3 on cell viability and cell wall stability of yeast Saccharomyces cerevisiae
• Author: Lucija Štrbac
• Mentor: Igor Stuparević (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Chemistry and Biochemistry); (Laboratory for Biochemistry); Zagreb
• Defense date and country: 2020-09-01, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Eukariotski RNA egzosom je esencijalan i evolucijski očuvani proteinski kompleks koji degradira i procesira RNA molekule u 3'-5' smjeru. Sastoji se od katalitički-inaktivne jezgre koja ulazi u interakciju s dvije ribonukleazne podjedinice, Dis3 i Rrp6, čije specifične uloge nisu u potpunosti razjašnjene. Podjedinica Dis3 esencijalna je za vijabilnost stanica te posjeduje endoribonukleaznu i egzoribonukleaznu aktivnost. Prethodno je pokazano kako inaktivacija egzoribonukleazne domene Dis3 rezultira sporijim rastom i osjetljivosti na povišenu temperaturu. Rezultati ovog rada pokazuju kako je sporiji rast ovog mutanta pri povišenoj temperaturi posljedica oslabljene stanične stijenke, zbog čega u hipoosmolarnom okruženju dolazi do pucanja stanica. U skladu s navedenim, letalnost i aberantnu morfologiju stanica ovog mutanta u potpunosti anulira osmotska stabilizacija hranjive podloge. Osim toga, stanice ovog mutanta osjetljivije su na agense koji oštećuju staničnu stijenku već pri fiziološkoj temperaturi. Destabilizacija stanične stijenke prilikom inaktivacije egzoribonukleazne, ali ne i endoribonukleazne domene Dis3 vjerojatno proizlazi iz poremećaja u regulaciji metabolizma RNA.

Abstract (english)

The eukaryotic RNA exosome is an essential and conserved protein complex that degrades or processes RNA substrates in the 3'-5' direction. It comprises a non-catalytic core that is associated with two ribonucleases, Dis3 and Rrp6, whose specific functions are not fully understood. Dis3 is essential for viability and has both endoribonuclease and exoribonuclease activity. It was previously shown that disruption of Dis3 exoribonuclease activity by a point mutation results in slow growth and temperature sensitivity. Our results show that the growth defect that these mutant cells display at high temperature is due to a weakened cell wall, which leads to bursting of cells under hypoosmolar conditions. In agreement with this, lethality and aberrant morphology of this mutant can be completely rescued by osmotically stabilizing the growth medium. Furthermore, these mutant cells show increased sensitivity to compounds that act as cell wall stressors already at physiological temperature. Cell wall destabilization upon disruption of Dis3 exoribonuclease, but not endoribonuclease activity, is most probably due to dysregulation of RNA metabolism.

• Keywords: Dis3; kvasac S. cerevisiae; RNA egzosom; stanična stijenka
• Keywords (english): cell wall; Dis3; RNA exosome; yeast S. cerevisiae
• Language: croatian
• URN:NBN: urn:nbn:hr:159:897244
• Study programme: Title: Biotechnology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-11-03 14:06:28