Dinamika proteina Rac1 te njena ovisnost o obliku stanice

master's thesis

• Title (english): Rac1 dynamics and its dependence on the cell shape
• Author: Blaž Ivšić
• Mentor: Igor Weber (mentor)
• Mentor: Nenad Pavin (mentor)
• Committee member: Nenad Pavin (predsjednik povjerenstva)
• Committee member: Igor Weber (član povjerenstva)
• Committee member: Mirko Planinić (član povjerenstva)
• Committee member: Nikola Poljak (član povjerenstva)
• Committee member: Davor Horvatić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Physics); Zagreb
• Defense date and country: 2019-09-30, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract

Kretanje stanica ovisi o polimerizaciji aktina, a nju reguliraju signalni proteini poput malih GTPaza. Poznato je da je aktivnost tih proteina u eukariotskim stanicama strukturirana u prostorno-vremenske obrasce poput stojnih i putujućih valova koji služe kao predlošci za polarizaciju aktinskog citoskeleta u funkcionalne domene. Dinamika male GTPaze Rac1 prethodno je modelirana pomoću reakcijsko-difuzijskih jednadžbi u jednoj prostornoj dimenziji, te je ustanovljeno da je pojava obrazaca uzrokovana dinamičkim nestabilnostima proizašlim iz nelinearnih interakcija medu proteinima, ali je pritom zanemaren utjecaj promjenjivog oblika stanice na dinamiku sustava. U ovom diplomskom radu poopćen je postojeći model tako da su opisane dvije prostorne dimenzije. Potom je razvijena numerička metoda za ispitivanje dinamike signalnih proteina i istraženo je na koji način oblik stanice utječe na pojavu obrazaca GTPaze Rac1. Teorijski su predvideni različiti prostorno-vremenski obrasci, uključujući putujuće i stojne valove. Također, laserskom pretraženom konfokalnom mikroskopijom eksperimentalno je proučavana dinamika fluorescentno obilježene sonde koja detektira aktivni oblik GTPaze Rac1 u stanicama Dictyostelium tijekom slobodnog kretanja. Dobiveni eksperimentalni rezultati uspoređeni su s teorijskim rezultatima te je zaključeno da uvedeni model dobro opisuje različite obrasce.

Abstract (english)

Cell movement depends on actin polymerization, which is regulated by signal proteins such as small GTPases. It is known that activity of these proteins in eukaryotic cells is structured in spatiotemporal patterns like travelling and stationary waves, which serve as templates for polarization of the actin cytoskeleton into functional domains. A model of Rac1 GTPase dynamics has been previously developed using reaction-diffusion equations in one dimension, which indicated that patterns are formed due to dynamic instabilities originating from non-linear protein interactions. However, a possible influence of cell shape on the system dynamics was not taken into account using this one-dimensional model. In this Diploma thesis we examine the influence of cell geometry on the pattern formation. Laser confocal microscopy was used to obtain data on the dynamics of a fluorecently labeled probe that specifically binds to the active form of Rac1 GTPase in vegetative Dictyostelium cells. Based on the existing model, a numerical method has been developed to investigate signal protein dynamics in two dimensions and determine how the cell shape influences formation of Rac1 GTPase patterns.

• Keywords: reakcijsko-difuzijski sustavi; metoda konačnih elemenata; aktinski citoskelet; stanično kretanje; Rho GTPaze
• Keywords (english): reaction–diffusion systems; finite element method; actin cytoskeleton; cell motility; rho GTPases
• Language: croatian
• URN:NBN: urn:nbn:hr:217:498904
• Study programme: Title: Physics; specializations in: Research; Course: Research; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra fizike (magistar/magistra fizike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-01-07 09:23:58