Utjecaj transkripcijskih regulatora bakterije Escherichia coli na učestalost formiranja čistina nakon infekcije bakteriofagom T4

master's thesis

• Title (english): The effect of Escherichia coli transcriptional regulators on efficiency of plaque formation of T4 bacteriophage
• Author: Sanja Srakočić
• Mentor: Ivana Ivančić Baće (mentor)
• Committee member: Ivana Ivančić Baće (predsjednik povjerenstva)
• Committee member: Martina Šeruga Musić (član povjerenstva)
• Committee member: Duje Lisičić (član povjerenstva)
• Committee member: Nataša Bauer (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2019-02-15, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Proteini H-NS i StpA su globalni transkripcijski represori iz bakterije Escherichia coli koji samostalno i zajedno reguliraju ekspresiju oko 20% gena. Njihova ekspresija je različito regulirana, gdje jedan drugog negativno reguliraju, a ekspresija im ovisi i o temperaturi inkubiranja. Geni čija je ekspresija regulirana samo proteinom H-NS se zovu unilateralni geni, a geni čija je ekspresija regulirana proteinima H-NS i StpA se zovu epistatski geni. Iz dosadašnjih istraživanja uočeno je da bakteriofag T4 iz nepoznatih razloga ne može formirati čistine u inficiranim bakterijskim stanicama Δhns pri temperaturi inkubacije od 30 oC. Cilj ovog rada bio je istražiti ulogu proteina StpA, nekoliko epistatskih gena, te proteaze Lon na uspješnost formiranja čistina bakteriofaga T4 u stanicama Δhns. Dobiveni rezultati ukazuju da nastanak čistina faga T4 u stanicama hns ovisi o proteinu StpA. Nedostatak proteaze Lon nije uspostavio nastanak čistina, kao niti jedan od istraživanih epistatskih gena cbl, cspA, dnaK, groL, htpG, rnc i sodA. Čistine faga T4 su uočene u soju E. coli B Δhns koji je prirodni mutant lon, što ukazuje da formiranje čistina faga T4 ovisi o nepoznatom razlikovnom genu između E. coli K-12 i E. coli B.

Abstract (english)

H-NS and StpA proteins are global transcriptional repressors of Escherichia coli that independently and together regulate the expression of about 20% of the genes. Their expression is regulated differently, they negatively regulate one another, and their expression also depends on the temperature of incubation. The genes whose expression is regulated by H-NS alone are called unilateral genes, and the genes whose expression is regulated by H-NS and StpA proteins are called epistatic genes. From recent studies, it has been found that bacteriophage T4 can not form plaques in infected Δhns cells incubated at a 30 °C for an unknown reasons. The aim of this study was to investigate the role of StpA protein, several epistatic genes and Lon protease on the efficiency of T4 bacteriophage plaque formation in Δhns cells. The obtained results indicate that T4 bacteriophage plaque formation depends on the StpA protein. The lack of protease Lon did not revert the plaque formation, as none of the investigated epistatic genes cbl, cspA, dnaK, groL, htpG, rnc and sodA. T4 bacteriophage plaques were observed in the E. coli B Δhns cells that is a natural lon mutant, indicating that plaque formation depends on the unidentified distinct gene between E. coli K-12 and E. coli B.

• Keywords: StpA; H-NS; proteaza Lon; T4; E.coli
• Keywords (english): StpA; H-NS; Lon protease; T4; E.coli
• Language: croatian
• URN:NBN: urn:nbn:hr:217:607257
• Study programme: Title: Molecular Biology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra molekularne biologije (magistar/magistra molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2020-02-15
• Created on: 2019-04-02 09:02:25