Mehanizmi unosa proteina kroz ovojnicu kloroplasta

undergraduate thesis

• Title (english): Mechanisms of protein import across chloroplast envelope
• Author: Petra Krznar
• Mentor: Željka Vidaković Cifrek (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2010, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Endosimbioza kao zajednica dvaju jednostavnih organizama rezultirala je nastankom kloroplasta, organela složene građe. Dvostruka membrana koja čini ovojnicu kloroplasta u kombinaciji s tilakoidnim membranama predstavlja zahtjevan sustav koji je zadržao vlastiti genom. Međutim, iz kloroplasta je tijekom evolucije velik broj gena prenesen u jezgru pa u ovaj plastid ulaze proteini sintetizirani na citosolnim ribosomima. Fotosinteza koja se odvija unutar kloroplasta, jedan je od najvažnijih procesa u živom svijetu. Za odvijanje tog procesa potrebni su strukturalno i funkcionalno raznoliki proteini. Fascinantan je njihov put i mehanizam unosa, koji uključuje vanjsku membranu ovojnice, međumembranski prostor, unutarnju membranu ovojnice te stromu i tilakoide. Put unosa uključuje komplekse Translocon of the Outer membranes of the Chloroplast (TOC) i Translocon of the Inner membranes of the Chloroplast (TIC), proteolitičku razgradnju tranzitnog peptida (TP) te formiranje konačne strukture pomoću šaperona. Nadalje, otkriveni su proteini koji ne prate takav obrazac unosa u kloroplast pa se postavlja pitanje jesu li to samo izuzeci ili pak postoje novi, alternativni načini unosa proteina koji će se otkriti u budućnosti.

Abstract (english)

Endosymbiosis of two simple organisms has resulted in development of chloroplast, an organelle with complicated architecture. In addition to inner and outer envelope membranes, chloroplasts contain thylakoids - a system of membranes inside the organelle. Although chloroplasts possess own genome, during the evolution a great number of genes are transferred from the chloroplast genome to the nuclear genome. Therefore, a number of proteins needed for chloroplast function are encoded by nuclear genome and synthesized on cytosolic ribosomes. They have to be imported into the chloroplast. Photosynthesis is one of the most important processes in living world and it is placed in chloroplast. Structurally and functionally diverse proteins are acquired for that important process. Their pathway and mechanism of import is fascinating. It includes outer membrane, inter-membrane space, inner membrane, stroma and thylakoids. It involves complexes Translocon of the Outer membranes of the Chloroplast (TOC) and Translocon of the Inner membranes of the Chloroplast (TIC), proteolitic removal of transit peptide (TP) and chaperones which help to create final structure. On the other hand, new proteins are discovered and they do not show that kind of importing pattern, so there is remaining question to be solved – are those proteins just exception or there is a new, alternative pathway of importing proteins into chloroplast?

• Keywords: mehanizmi unosa proteina; ovojnica kloroplasta
• Keywords (english): mechanisms of protein import; chloroplast envelope
• Language: croatian
• URN:NBN: urn:nbn:hr:217:850421
• Study programme: Title: Molecular Biology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-03-27 10:52:28