Utjecaj prekomjerne sinteze proteina stanične stijenke Scw4p na fenotip kvasca S. cerevisiae

undergraduate thesis

• Title (english): The effect of over-expression of cell wall Scw4p protein on S. cerevisiae phenotype characteristics
• Author: Terezija Miškić
• 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: 2014-06-11, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Nutrition

Abstract

Protein Scw4p je jedan od najzastupljenijih nekovalentno vezanih proteina stanične stijenke, čija fiziološka uloga u stijenci još uvijek nije poznata. U ovom radu je ispitivana potencijalna fiziološka uloga Scw4p ispitivanjem fenotipskih karakteristika mutiranih stanica kvasaca koje sintetiziraju povećanu količinu tog proteina. Prekomjerna sinteza Scw4p u stanicama divljeg tipa kvasca, kex2 mutanta i japsinskog mutanta dovodi do smanjenja viabilnosti stanica sva tri soja kvasca, pri čemu je veće smanjenje viabilnosti postignuto pri pH=4 nego pri pH=7. Prekomjerna sinteza Scw4p u stanicama divljeg tipa kvasca i japsinskog mutanta dovodi do povećanja osjetljivosti na djelovanje zimolijaze, dok kod stanica kex2 mutanta nema efekta. Na osnovu ovih rezultata može se zaključiti da protein Scw4p djeluje kao glukanaza, jer pri njegovoj povećanoj sintezi dolazi do pada vijabilnosti i povećanja osjetljivosti stanica na djelovanje hidrolitičkih enzima iz okoline. Enzimski aktivna je procesirana forma Scw4p, pri čemu se jači efekt aktivacije postiže djelovanjem Kex2p proteaze, a slabiji djelovanjem japsinskih proteaza.

Abstract (english)

One of the most abundant noncovalently linked cell wall proteins is Scw4p and its role in the cell wall has not yet been discovered. This paper examines the potential physiological role of this protein. The phenotype characteristics of mutant yeast cells that over-express Scw4p protein are questioned. The over-expression of Scw4p in wild type yeast cells, in kex2 mutant cells, and in yapsin mutants lowers the viability of every type of yeast cell. Greater infuluence of decreasing viability was achieved under pH=4 than under pH=7 conditions. Also, the over-expression of Scw4p in wild type yeast cells and in yapsin mutants increases the sensibility to zymoliase treatment and there is no effect at all in kex2 mutants. Such results indicate that protein Scw4p has glucanase activity and its active form is a processed form, wherein a greater activation effect is achieved with Kex2p proteases and lower one with yapsine proteases.

• 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:159:311458
• Study programme: Title: Nutrition; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) nutricionizma (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) nutricionizma)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-04-27 13:53:01