Multifunkcionalna svojstva biljnih proteina: citoplazmatska gliceraldehid-3-fosfat dehidrogenaza kao moonlighting protein

undergraduate thesis

• Title (english): Multifunctional properties of plant proteins: citoplasmic glyceraldehyde-3-phosphate dehydrogenase as a moonlighting protein
• Author: Sanja Srakočić
• Mentor: Biljana Balen (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2016, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Biljna citoplazmatska gliceraldehid-3-fosfat-dehidrogenaza (GAPDH) je glikolitički enzim ovisan o kofaktoru NAD+. Za njenu enzimsku aktivnost je neophodan katalitički Cys-154. Osim uloge u glikolizi biljna citoplazmatska GAPDH obavlja i dodatne, moonlighting funkcije. Moonlighting funkcije su kontrolirane redoks posttranslacijskim modifikacijama katalitičkog Cys čime se inhibira enzimska aktivnost GAPDH. Katalitički Cys se u fiziološkim uvjetima nalazi u deprotoniranom obliku, zato je jaki nukleofil i podložan je redoks modifikacijama. Najčešće redoks modifikacije su S-nitrozilacija, glutationilacija i oksidacija. Redoks modifikacije mogu biti reverzibilne i ireverzibilne, a za moonlighting funkcije biljne citoplazmatske GAPDH su bitne reverzibilne modifikacije. Oksidacijski uvjeti uzrokuju promjenu položaja citoplazmatske GAPDH u stanici. Citoplazmatska GAPDH se premjesti u jezgru, veže se na membranu mitohondrija, staničnu membranu i na elemente citoskeleta. Također stupa u interakciju sa drugim proteinima i tvori proteinske komplekse. Za razliku od moonlighting funkcija animalne GAPDH, moonlighting funkcije biljne citoplazmatske GAPDH još uvijek nisu dovoljno istražene. Cilj ovog rada je dati pregled dosadašnjih istraživanja koja daju uvid u regulaciju i posljedice moonlighting funkcija biljne citoplazmatske GAPDH.

Abstract (english)

Plant cytoplasmic glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is enzyme involved in glycolysis that uses NAD+ as a cofactor. The most important catalytic residue is Cys-154. Apart from its role in glycolysis, plant citoplasmic GAPDH has additional, moonlighting functions. Moonlighting functions are regulated by post-translational redox modifications of catalytic Cys residue which inhibits GAPDH enzymatic activity. In physiological conditions the thiol group of the catalytic Cys is deprotonated which makes it strog nucleophil that can undergo redox modifications. The most common redox modifications are S-nitrosylation, glutathionylation and oxidation. There are two types of redox modifications: reversible and irreversible. Moonlighting functions of plant cytoplasmic GAPDH are triggered by reversible redox modifications. Oxidizing conditions in plant cell cause changes in subcellular localization. Citoplasmic GAPDH can translocate into nucleus, associate with outer membrane of mitochondria, plasma membrane or cytoskeleton. Citoplasmic GAPDH can also associate with other proteins and form protein complexes. In contrast with the well established moonlighting functions of animal GAPDH, little is known about moonlighting properties of plant citoplasmic GAPDH. The aim of this review is to summarize previous research and provide an insight into regulation of moonlighting properties of plant citoplasmic GAPDH.

• Keywords: gliceraldehid-3-fosfat-dehidrogenaza; moonlighting protein
• Keywords (english): glyceraldehyde-3-phosphate dehydrogenase; moonlighting protein
• Language: croatian
• URN:NBN: urn:nbn:hr:217:362944
• 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: 2018-01-04 09:06:22