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doctoral thesis
Uloga proteina IqgC u regulaciji makropinocitoze u amebi Dictyostelium discoideum
Zagreb: University of Zagreb, Faculty of Science, 2024. urn:nbn:hr:217:491160
Putar Brajković, Darija
University of Zagreb
Faculty of Science

Institutional repository: Repository of the Faculty of Science

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Putar Brajković, D. (2024). Uloga proteina IqgC u regulaciji makropinocitoze u amebi Dictyostelium discoideum (Doctoral thesis). Zagreb: University of Zagreb, Faculty of Science. Retrieved from https://urn.nsk.hr/urn:nbn:hr:217:491160

Putar Brajković, Darija. "Uloga proteina IqgC u regulaciji makropinocitoze u amebi Dictyostelium discoideum." Doctoral thesis, University of Zagreb, Faculty of Science, 2024. https://urn.nsk.hr/urn:nbn:hr:217:491160

Putar Brajković, Darija. "Uloga proteina IqgC u regulaciji makropinocitoze u amebi Dictyostelium discoideum." Doctoral thesis, University of Zagreb, Faculty of Science, 2024. https://urn.nsk.hr/urn:nbn:hr:217:491160

Putar Brajković, D. (2024). 'Uloga proteina IqgC u regulaciji makropinocitoze u amebi Dictyostelium discoideum', Doctoral thesis, University of Zagreb, Faculty of Science, accessed 24 November 2024, https://urn.nsk.hr/urn:nbn:hr:217:491160

Putar Brajković D. Uloga proteina IqgC u regulaciji makropinocitoze u amebi Dictyostelium discoideum [Doctoral thesis]. Zagreb: University of Zagreb, Faculty of Science; 2024 [cited 2024 November 24] Available at: https://urn.nsk.hr/urn:nbn:hr:217:491160

D. Putar Brajković, "Uloga proteina IqgC u regulaciji makropinocitoze u amebi Dictyostelium discoideum", Doctoral thesis, University of Zagreb, Faculty of Science, Zagreb, 2024. Available at: https://urn.nsk.hr/urn:nbn:hr:217:491160

Metadata
TitleUloga proteina IqgC u regulaciji makropinocitoze u amebi Dictyostelium discoideum
Title (english)The role of IqgC protein in the regulation of macropinocytosis in amoeba Dictyostelium discoideum
AuthorDarija Putar Brajković
MentorVedrana Filić Mileta (mentor)
Committee memberMaja Herak-Bosnar (predsjednik povjerenstva)
Committee memberIgor Weber (član povjerenstva)
Committee memberBiljana Balen (član povjerenstva)
GranterUniversity of Zagreb
Faculty of Science
Zagreb
Defense date and country2024-02-21, Croatia
Scientific / art field,
discipline and subdiscipline		NATURAL SCIENCES
Biology
Universal decimal classification
(UDC)		577 - Biochemistry. Molecular biology. Biophysics
Abstract
Protein IqgC iz protista D. discoideum djeluje kao GAP (GTPase activating protein) prema GTPazi RasG, čime je deaktivira i tako suprimira makropinocitozu. Međutim, kako je makropinocitoza u akseničnim sojevima ovog organizma konstitutivno pojačana, delecija gena iqgC u akseničnom soju rezultirala je neznatnim pojačanjem makropinocitoze. U ovom radu pokazala sam da delecija gena iqgC ima znatno veću pozitivnu ulogu u regulaciji makropinocitoze u soju divljeg tipa čija makropinocitoza je uvelike suprimirana. Nadalje, ustanovila sam da je RasG neophodan za vezanje IqgC na membranu makropinosoma, dok interakcija IqgC s fosfoinozitidima doprinosi stabilizaciji vezanja. Pokazala sam također da IqgC izravno interagira s GTPazom Rab5A, ali ne utječe na njenu GTPaznu aktivnost, dok suvišak Rab5A inhibira GAP aktivnost IqgC prema RasG in vitro. Također, prekomjerna ekspresija Rab5A izaziva preuranjenu disocijaciju IqgC s makropinosoma. Dobiveni rezultati pokazuju da, osim interakcije proteina IqgC i RasG, interakcija IqgC i Rab5A također igra ulogu u regulaciji makropinocitoze.
Abstract (english)
The D. discoideum protein IqgC is a RasG-specific GAP (GTPase activating protein) that negatively regulates macropinocytosis. However, deletion of iqgC in the axenic strain induced only a minor enhancement of macropinocytosis, as axenic cells already exhibit upregulated fluid uptake. Therefore, in this work, I deleted iqgC in the wild-type strain, whose macropinocytosis is largely suppressed, and demonstrated a more pronounced positive effect on fluid uptake upon IqgC depletion. Furthermore, I demonstrated that RasG is essential for IqgC recruitment to macropinosomes, while IqgC binding to phosphoinositides likely contributes to stabilization of the association. I showed that IqgC also interacts with GTPase Rab5A but does not affect its activity. Actually, an excessive amount of Rab5A inhibits the GAP activity of IqgC towards RasG in vitro and induces premature dissociation of IqgC from the macropinosome in vivo. These results suggest that interactions between IqgC and both GTPases play a regulatory role in macropinocytosis.
Keywords
Keywords (english)
Languagecroatian
URN:NBNurn:nbn:hr:217:491160
Promotion2024
ProjectNumber: IP-2020-02-1572
Title: Regulacija endocitoze na velikoj skali pomoću IQGAP proteinima srodnih proteina IqgC i IqgD
Acronym: RegEndIqCD
Leader: Vedrana Filić Mileta
Jurisdiction: Croatia
Funder: HRZZ
Funding stream: IP
ProjectNumber: 180584
Title: Phagocytosis and Macropinocytosis, a mechanistic view
Leader: Igor Weber
Jurisdiction: Croatia
Funder: HRZZ
Funding stream: HSIP
Study programmeTitle: Doctoral study
Study programme type: university
Study level: postgraduate
Academic / professional title: doktor/doktorica znanosti u području prirodnih znanosti (doktor/doktorica znanosti u području prirodnih znanosti)
Type of resourceText
File originBorn digital
Access conditionsOpen access
Terms of useLicence In copyright icon
Created on2024-02-27 10:34:53