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The effect of ganglioside composition on expression, submembrane localization and activity of Na+, K+-ATPase and plasma membrane Ca2+-ATPase in mouse brain
No full textU mišjim modelima s poremećenom sintezom glikosfingolipida gangliozida dolazi do promjene u lipidnom okolišu membrane potrebnom za pravilno funkcioniranje membranskih proteina. Cilj ovog istraživanja bio je višerazinskim metodološkim pristupom sustavno utvrditi utjecaj promijenjenog sastava gangliozida u mišjem modelu St8sia1 null na gensku i proteinsku ekspresiju, te submembransku lokalizaciju pojedinih izoformi i podjedinica Na+, K+-ATPaze (NKA), Ca2+-ATPaze stanične membrane (PMCA) i neuroplastina (Np), kao i na enzimsku aktivnost NKA i PMCA u različitim regijama mozga. Analizom genske ekspresije metodom lančane reakcije polimerazom u stvarnom vremenu utvrđene su promjene u ekspresiji gena za katalitičke i β- podjedinice NKA, izoforme PMCA između moždane kore, maloga mozga i hipokampusa miševa St8sia1 null u odnosu na kontrolnu skupinu, ukazujući na različitu staničnu potrebu za pojedinim izoformama, dok je u sve tri regije mozga utvrđen porast ekspresije gena za neuroplastin. Westernskom metodom otiska pokazano je da dolazi do promjene u količinskom sadržaju istraživanih proteina u regijama mozga St8sia1 null u vidu porasta količine katalitičkih podjedinica NKA te izoforme PMCA2 u moždanoj kori, PMCA4 u malome mozgu, te PMCA3 i 4 u hipokampusu miševa St8sia1 null ukazujući na različitu staničnu potrebu za pojedinim izoformama različitih kinetičkih svojstava. Analizom submembranske lokalizacije navedenih proteina utvrđen je proces njihove redistribucije u analiziranim regijama mozga miševa St8sia1 null. Analizom enzimskih aktivnosti NKA i PMCA utvrđeno je kako dolazi do pada aktivnosti u moždanoj kori i malome mozgu miševa St8sia1 null uslijed ukupnih biokemijskih promjena uzrokovanim promijenjenim gangliozidnim sastavom membrane. Dodavanjem egzogenih gangliozida b- serije uspostavljen je porast enzimske aktivnosti NKA i PMCA, dajući ovom istraživanju translacijski potencijal. Rezultati istraživanja nedvojbeno pokazuju da promijenjen sastav gangliozida ima dalekosežne posljedice po funkcioniranje ubikvitarnih staničnih membranskih prijenosnika iona.Mice models with altered biosynthesis of glycosphingolipids gangliosides have altered membrane lipid environment necessary for the proper function of membrane proteins. The aim of this thesis was to systematically determine the effect of altered ganglioside composition on gene and protein expression, submembrane localization of specific isoforms and subunits of Na+, K+-ATPase (NKA), plasma membrane Ca2+-ATPase (PMCA) and neuroplastin (Np), and enzyme activity of NKA and PMCA in different brain regions of St8sia1 null mice. Gene expression analysis revealed changes in expression profiles of different PMCA isoforms and NKA subunits in null mice compared to their controls, indicating the different cellular need for specific isoforms. Neuroplastin gene expression was higher in all analysed regions. Higher protein content of catalytic NKA subunits and PMCA2 isoforms in the cortex, PMCA4 in the cerebellum, and of PMCA3 and PMCA4 isoforms in the hippocampus was determined in null mice illustrating the cellular needs for specific subunits with differing kinetic parameters. Altered submembrane localization of investigated proteins shows their redistribution between different membrane subdomains. Described biochemical changes stemming from altered ganglioside composition, cause lower enzyme activities of NKA and PMCA determined in cortices and cerebella of null mice. We were able to rescue NKA and PMCA activity by administration of exogenous b- series gangliosides, giving this research translational potential. The results of this thesis unequivocally show that changes in ganglioside microenvironment have considerable consequences on the function of membrane ion transporters
The effect of ganglioside composition on expression, submembrane localization and activity of Na+, K+-ATPase and plasma membrane Ca2+-ATPase in mouse brain
No full textU mišjim modelima s poremećenom sintezom glikosfingolipida gangliozida dolazi do promjene u lipidnom okolišu membrane potrebnom za pravilno funkcioniranje membranskih proteina. Cilj ovog istraživanja bio je višerazinskim metodološkim pristupom sustavno utvrditi utjecaj promijenjenog sastava gangliozida u mišjem modelu St8sia1 null na gensku i proteinsku ekspresiju, te submembransku lokalizaciju pojedinih izoformi i podjedinica Na+, K+-ATPaze (NKA), Ca2+-ATPaze stanične membrane (PMCA) i neuroplastina (Np), kao i na enzimsku aktivnost NKA i PMCA u različitim regijama mozga. Analizom genske ekspresije metodom lančane reakcije polimerazom u stvarnom vremenu utvrđene su promjene u ekspresiji gena za katalitičke i β- podjedinice NKA, izoforme PMCA između moždane kore, maloga mozga i hipokampusa miševa St8sia1 null u odnosu na kontrolnu skupinu, ukazujući na različitu staničnu potrebu za pojedinim izoformama, dok je u sve tri regije mozga utvrđen porast ekspresije gena za neuroplastin. Westernskom metodom otiska pokazano je da dolazi do promjene u količinskom sadržaju istraživanih proteina u regijama mozga St8sia1 null u vidu porasta količine katalitičkih podjedinica NKA te izoforme PMCA2 u moždanoj kori, PMCA4 u malome mozgu, te PMCA3 i 4 u hipokampusu miševa St8sia1 null ukazujući na različitu staničnu potrebu za pojedinim izoformama različitih kinetičkih svojstava. Analizom submembranske lokalizacije navedenih proteina utvrđen je proces njihove redistribucije u analiziranim regijama mozga miševa St8sia1 null. Analizom enzimskih aktivnosti NKA i PMCA utvrđeno je kako dolazi do pada aktivnosti u moždanoj kori i malome mozgu miševa St8sia1 null uslijed ukupnih biokemijskih promjena uzrokovanim promijenjenim gangliozidnim sastavom membrane. Dodavanjem egzogenih gangliozida b- serije uspostavljen je porast enzimske aktivnosti NKA i PMCA, dajući ovom istraživanju translacijski potencijal. Rezultati istraživanja nedvojbeno pokazuju da promijenjen sastav gangliozida ima dalekosežne posljedice po funkcioniranje ubikvitarnih staničnih membranskih prijenosnika iona.Mice models with altered biosynthesis of glycosphingolipids gangliosides have altered membrane lipid environment necessary for the proper function of membrane proteins. The aim of this thesis was to systematically determine the effect of altered ganglioside composition on gene and protein expression, submembrane localization of specific isoforms and subunits of Na+, K+-ATPase (NKA), plasma membrane Ca2+-ATPase (PMCA) and neuroplastin (Np), and enzyme activity of NKA and PMCA in different brain regions of St8sia1 null mice. Gene expression analysis revealed changes in expression profiles of different PMCA isoforms and NKA subunits in null mice compared to their controls, indicating the different cellular need for specific isoforms. Neuroplastin gene expression was higher in all analysed regions. Higher protein content of catalytic NKA subunits and PMCA2 isoforms in the cortex, PMCA4 in the cerebellum, and of PMCA3 and PMCA4 isoforms in the hippocampus was determined in null mice illustrating the cellular needs for specific subunits with differing kinetic parameters. Altered submembrane localization of investigated proteins shows their redistribution between different membrane subdomains. Described biochemical changes stemming from altered ganglioside composition, cause lower enzyme activities of NKA and PMCA determined in cortices and cerebella of null mice. We were able to rescue NKA and PMCA activity by administration of exogenous b- series gangliosides, giving this research translational potential. The results of this thesis unequivocally show that changes in ganglioside microenvironment have considerable consequences on the function of membrane ion transporters
Changes in plastid proteome during chloroplast-to-chromolast transition
Full text linkTransformacija kloroplasta u kromoplaste važan je biološki proces tijekom zriobe plodova. Događaju se važne strukturne i metaboličke promjene. Spektralna konfokalna mikroskopska analiza karotenoida i klorofila u plastidima izoliranih iz plodova pokazala je da kromoplasti nastaju iz već postojećih kloroplasta te da se nakon kromoplastogeneze proces diferencijacije završava. Snimanje živog tkiva in situ tehnikom real-time pokazalo je da je proces sinkroniziran na nivou jedne stanice, ali ne i na nivou čitavog tkiva. Proteomske analize dale su bolji uvid u metaboličke promjene tijekom kromoplastogeneze. Promjene u metabolizmu sastoje se od smanjenja količine proteina svjetlosnih reakcija, uključujući proteine uključene u fotosintezu, Calvinov ciklus i fotorespiraciju. Smanjuje se i količina proteina uključenih u metabolizam ugljikohidrata. Raste količina proteina stresa, kao i proteina uključenih u biosintezu terpenoida, uključujući karotenoide. Zanimljiva je činjenica velike prisutnosti podjedinica enzima RUBISCO u kromoplastima, iako se enzim prvenstveno nalazi u fotosintetski aktivnim plastidima. Navedenim metaboličkim promjenama prethodi akumulacija acetil-CoA karboksilaze koja je važna za formiranje spremišnog matriksa u kojemu će se akumulirati karotenoidi. Metaboličke promjene praćene su strukturnim promjenama. Poremećena je biogeneza tilakoida i fotosistema, a dolazi i do povećane proizvodnje energije i gubitka sposobnosti diobe plastida.Transition from chloroplasts to chromoplasts is an important biological process in fruit ripening. Many significant structural and metabolic shifts occur. Spectral confocal microscopy analyses of carotenoids and chlorophylls in isolated fruit plastids showed that chromoplasts arise from already existing chloroplasts, and that no further differentiation process occur. Real-time in-situ recording of intact live tissue showed that the process is synchronized within a cell, but with less synchrony within the whole tissue. Proteomic analyses gave better insight into metabolic shifts during chromoplastogenesis. Major shifts included decrease in abundance of proteins involved in light reactions, including photosynthesis, Calvin cycle and photorespiration. Proteins involved in carbohydrate metabolism also decrease in abundance. Proteins whose abundance increases during chromoplastogenesis include stress proteins, and proteins related to terpenoid biosynthesis. One interesting feature is that the large subunit of the RUBISCO enzyme, an enzyme typically abundant in photosynthetic plastids, although continuously decreasing in abundance, is present in fully developed chromoplasts. These metabolic shifts are preceded by the accumulation of acetyl CoA carboxylase, which accounts for the generation of a storage matrix that will accumulate carotenoids. Metabolic shifts are followed by structural changes. The biogenesis of the machinery for building up of thylakoid and photosystems is disrupted, coupled with elevated energy production components and loss of plastid division machinery
The effect of ganglioside composition on expression, submembrane localization and activity of Na+, K+-ATPase and plasma membrane Ca2+-ATPase in mouse brain
No full textU mišjim modelima s poremećenom sintezom glikosfingolipida gangliozida dolazi do promjene u lipidnom okolišu membrane potrebnom za pravilno funkcioniranje membranskih proteina. Cilj ovog istraživanja bio je višerazinskim metodološkim pristupom sustavno utvrditi utjecaj promijenjenog sastava gangliozida u mišjem modelu St8sia1 null na gensku i proteinsku ekspresiju, te submembransku lokalizaciju pojedinih izoformi i podjedinica Na+, K+-ATPaze (NKA), Ca2+-ATPaze stanične membrane (PMCA) i neuroplastina (Np), kao i na enzimsku aktivnost NKA i PMCA u različitim regijama mozga. Analizom genske ekspresije metodom lančane reakcije polimerazom u stvarnom vremenu utvrđene su promjene u ekspresiji gena za katalitičke i β- podjedinice NKA, izoforme PMCA između moždane kore, maloga mozga i hipokampusa miševa St8sia1 null u odnosu na kontrolnu skupinu, ukazujući na različitu staničnu potrebu za pojedinim izoformama, dok je u sve tri regije mozga utvrđen porast ekspresije gena za neuroplastin. Westernskom metodom otiska pokazano je da dolazi do promjene u količinskom sadržaju istraživanih proteina u regijama mozga St8sia1 null u vidu porasta količine katalitičkih podjedinica NKA te izoforme PMCA2 u moždanoj kori, PMCA4 u malome mozgu, te PMCA3 i 4 u hipokampusu miševa St8sia1 null ukazujući na različitu staničnu potrebu za pojedinim izoformama različitih kinetičkih svojstava. Analizom submembranske lokalizacije navedenih proteina utvrđen je proces njihove redistribucije u analiziranim regijama mozga miševa St8sia1 null. Analizom enzimskih aktivnosti NKA i PMCA utvrđeno je kako dolazi do pada aktivnosti u moždanoj kori i malome mozgu miševa St8sia1 null uslijed ukupnih biokemijskih promjena uzrokovanim promijenjenim gangliozidnim sastavom membrane. Dodavanjem egzogenih gangliozida b- serije uspostavljen je porast enzimske aktivnosti NKA i PMCA, dajući ovom istraživanju translacijski potencijal. Rezultati istraživanja nedvojbeno pokazuju da promijenjen sastav gangliozida ima dalekosežne posljedice po funkcioniranje ubikvitarnih staničnih membranskih prijenosnika iona.Mice models with altered biosynthesis of glycosphingolipids gangliosides have altered membrane lipid environment necessary for the proper function of membrane proteins. The aim of this thesis was to systematically determine the effect of altered ganglioside composition on gene and protein expression, submembrane localization of specific isoforms and subunits of Na+, K+-ATPase (NKA), plasma membrane Ca2+-ATPase (PMCA) and neuroplastin (Np), and enzyme activity of NKA and PMCA in different brain regions of St8sia1 null mice. Gene expression analysis revealed changes in expression profiles of different PMCA isoforms and NKA subunits in null mice compared to their controls, indicating the different cellular need for specific isoforms. Neuroplastin gene expression was higher in all analysed regions. Higher protein content of catalytic NKA subunits and PMCA2 isoforms in the cortex, PMCA4 in the cerebellum, and of PMCA3 and PMCA4 isoforms in the hippocampus was determined in null mice illustrating the cellular needs for specific subunits with differing kinetic parameters. Altered submembrane localization of investigated proteins shows their redistribution between different membrane subdomains. Described biochemical changes stemming from altered ganglioside composition, cause lower enzyme activities of NKA and PMCA determined in cortices and cerebella of null mice. We were able to rescue NKA and PMCA activity by administration of exogenous b- series gangliosides, giving this research translational potential. The results of this thesis unequivocally show that changes in ganglioside microenvironment have considerable consequences on the function of membrane ion transporters
Variability in exons of CYP2D6 gene in Croatian Roma populations
Full text linkGen CYP2D6 kodira protein koji sudjeluje u metabolizmu 25% često prepisanih lijekova i drugih tvari iz okoliša. Ovaj gen vrlo je polimorfan što rezultira visokom ekspesijskom varijabilnošću među pojedincima i populacijama. U ovome radu su GT-seq metodom sekvencirani egzoni gena CYP2D6 u populacijama Roma iz Baranje, Međimurja i Zagreba s ciljem utvrđivanja intra- i interpopulacijske različitosti temeljem varijabilnosti egzona gena CYP2D6. U usporedbi s referentnom sekvencom u ukupnom istraživanom uzorku uočena su 24 polimorfna lokusa od kojih kod četri nije u skladu s Hardy- Weinbergovom ravnotežom. Ustanovljene su različite učestalosti mutacija između proučavanih populacija, te je utvrđena statistički značajna razlika u učestalostima genotipova između proučavanih populacija. Između parova lokusa u tri proučavane populacije detektirana je značajna neravnoteža vezanosti. Ovo istraživanje je potvrdilo genetske specifičnosti romskih populacija koje su posljedica njihove izoliranosti uzrokovane endogamijom, te još uvijek izraženog učinka utemeljitelja. Utvrđene varijabilnosti u genu CYP2D6 za posljedicu mogu imati učinak na uspješnost farmakoloških terapija.The CYP2D6 gene codes for a protein which takes part in the metabolism of 25% commonly perscribed drugs and other xenobiotics. The CYP2D6 gene is very polimorfic, and its expression varies between individuals and among populations. In this research exons of the CYP2D6 gene were sequenced by the GT-seq method in three Roma populations, from Baranja and Međimurje regions and the city of Zagreb in order to determine intra- and interpopulation variability based on CYP2D6 exons. 24 loci were shown to be polimorfic and 4 of them were shown not to be in the Hardy-Weinberg equilibrium. Different frequencies of mutated allels and genotypes were shown to occur among the analyzed populations. Significant linkage disequilibrium was determined between a few pairs of loci. This research has shown a specific genetic profile of the three isoalted Roma populations. Their genetic specificities reflect the founder effect from their demographic history and the still existing endogamy practice. Detected variabilities in the CYP2D6 gene may have an effect on the efficiency of different pharmacological therapies
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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