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Sulfur transfer and activation by ubiquitin-like modifier system Uba4•Urm1 link protein urmylation and tRNA thiolation in yeast
(2016-10-24)
Urm1 is a unique dual-function member of the ubiquitin protein family and conserved from yeast to man. It acts both as a protein modifier in ubiquitin-like urmylation and as a sulfur donor for tRNA thiolation, which in concert with the Elongator pathway forms 5-methoxy-carbonyl-methyl-2-thio (mcm5s2) modified wobble uridines (U34) in anticodons. Using Saccharomyces cerevisiae as a model to study a relationship between these two functions, we examined whether cultivation temperature and sulfur supply previously ...
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Role of Pseudouridine Formation by Deg1 for Functionality of Two Glutamine Isoacceptor tRNAs
(2017-01-26)
Loss of Deg1/Pus3 and concomitant elimination of pseudouridine in tRNA at positions 38 and 39 (ψ38/39) was shown to specifically impair the function of tRNAGlnUUG under conditions of temperature-induced down-regulation of wobble uridine thiolation in budding yeast and is linked to intellectual disability in humans. To further characterize the differential importance of the frequent ψ38/39 modification for tRNAs in yeast, we analyzed the in vivo function of non-sense suppressor tRNAs SUP4 and sup70-65 in the absence ...
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Loss of Anticodon Wobble Uridine Modifications Affects tRNALys Function and Protein Levels in Saccharomyces cerevisiae
(2015)
In eukaryotes, wobble uridines in the anticodons of tRNALysUUU, tRNAGluUUC and tRNAGlnUUG are modified to 5-methoxy-carbonyl-methyl-2-thio-uridine (mcm5s2U). While mutations in subunits of the Elongator complex (Elp1-Elp6), which disable mcm5 side chain formation, or removal of components of the thiolation pathway (Ncs2/Ncs6, Urm1, Uba4) are individually tolerated, the combination of both modification defects has been reported to have lethal effects on Saccharomyces cerevisiae. Contrary to such absolute requirement ...
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Loss of wobble uridine modification in tRNA anticodons interferes with TOR pathway signaling
(2014)
Previous work in yeast has suggested that modification of tRNAs, in particular uridine bases in the anticodon wobble position (U34), is linked to TOR (target of rapamycin) signaling. Hence, U34 modification mutants were found to be hypersensitive to TOR inhibition by rapamycin. To study whether this involves inappropriate TOR signaling, we examined interaction between mutations in TOR pathway genes (tip41Δ, sap190Δ, ppm1Δ, rrd1Δ) and U34 modification defects (elp3Δ, kti12Δ, urm1Δ, ncs2Δ) and found the rapamycin ...
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Die Masse macht's!
(GIT VERLAG GmbH & Co. KG - A Wiley Company, 2008-09)
Die biochemische Beschreibung funktioneller Proteininteraktionsnetzwerke hat in den letzten Jahren einen starken Wandel erfahren. Mittels hochauflösender biologischer Massenspektrometrie(MS) ist es möglich Netzwerkkomponenten, wie Proteine schnell und zuverlässig zu identifizieren und auf ihre Modifikationen hin zu untersuchen.
Innerhalb des Promotionskollegs (PK) Proteomics der Universität Kassel bietet die MS neue Ansatzpunkte für die Beantwortung molekularbiologischer Fragestellungen und liefert Ergänzungen zu ...
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Signaling of Pigment-Dispersing Factor (PDF) in the Madeira Cockroach Rhyparobia maderae
(2014)
The insect neuropeptide pigment-dispersing factor (PDF) is a functional ortholog of vasoactive intestinal polypeptide, the coupling factor of the mammalian circadian pacemaker. Despite of PDF's importance for synchronized circadian locomotor activity rhythms its signaling is not well understood. We studied PDF signaling in primary cell cultures of the accessory medulla, the circadian pacemaker of the Madeira cockroach. In Ca2+ imaging studies four types of PDF-responses were distinguished. In regularly bursting type ...