Ispitivanje procesiranja nativnog i mutiranih oblika Scw4p proteina stanične stijenke kvasca S. Cerevisiae i utjecaja njegove prekomjerne ekspresije na viabilnost stanica kvasca

undergraduate thesis

• Title (english): Investigation of processing of the native and mutated forms of S. Cerevisiae cell wall protein Scw4p and impact of its overexpression on the viability of the yeast cells
• Author: Katarina Brkan
• Mentor: Renata Teparić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Chemistry and Biochemistry); (Laboratory for Biochemistry); Zagreb
• Defense date and country: 2015-07-08, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Protein Scw4p jedan je od najzastupljenijih nekovalentno vezanih proteina u staničnoj stijenci kvasca, a njegova fiziološka uloga još nije poznata. U ovom radu ispitivan je utjecaj mutacija u potencijalnim mjestima za procesiranje na procesiranje samog proteina Scw4p, čime je potvrđeno su da su ranije uočene razlike u molekulskoj masi različitih formi Scw4p izoliranog iz stanične stijenke kvasca posljedica njegovog proteolitičkog procesiranja s Kex2p i/ili japsinskim proteazama. Također, ispitivan je utjecaj prekomjerne sinteze nativnog proteina Scw4p i Scw4p s uvedenim mutacijama u potencijalna mjesta za procesiranje Kex2p proteazom i japsinskim proteazama na viabilnost stanica kvasca u različitim fazama rasta kvasca. Na osnovu dobivenih rezultata može se zaključiti da prekomjerna ekspresija Scw4p uzrokuje porast smrtnosti stanica kvasca u logaritamskoj fazi rasta, dok u stacionarnoj fazi rasta održava udio mrtvih stanica 5-6 puta manjim nego u slučaju normalnog nivoa ekspresije Scw4p. Najmanji utjecaj na smrtnost stanica pokazuje neprocesirani oblik proteina Scw4p, što vjerojatno znači da su enzimski aktivne procesirane forme ovog proteina.

Abstract (english)

Scw4p protein is one of the most abundant noncovalently linked cell wall proteins and its physiological role still remains unknown. In this paper, we studied the effect of mutations in potential processing sites onto the protein Scw4p processing, which confirmed that the previously observed differences in the molecular weight of different Scw4p forms, isolated from the yeast cell wall, were a consequence of its proteolytic processing with Kex2p and/or yapsin proteases. Also, we examined the effect of excessive synthesis of the native Scw4p and mutated Scw4p protein in the potential processing site of Kex2p protease and yapsin proteases on the viability of yeast cells in different stages of yeast growth. Based on the results obtained, it can be concluded that the overexpression of Scw4p protein causes increased mortality of yeast cells during the logarithmic growth phase, while during the stationary growth phase it maintains the percentage of dead cells 5-6 times smaller than in the case of regular Scw4p expression levels. The unprocessed form of Scw4p protein exhibits the smallest impact on mortality of cells, which probably means that processed forms of this proteins are active.

• Keywords: stanična stijenka kvasca; Scw4p; Kex2p; japsinske proteaze
• Keywords (english): yeast cell wall; Scw4p protein; Kex2p; yapsine proteins
• Language: croatian
• URN:NBN: urn:nbn:hr:159:947668
• 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: Access restricted to students and staff of home institution
• Created on: 2017-04-25 10:45:19