Now showing 1 - 3 of 3
  • 2008Journal Article
    [["dc.bibliographiccitation.firstpage","5412"],["dc.bibliographiccitation.issue","11"],["dc.bibliographiccitation.journal","Biophysical Journal"],["dc.bibliographiccitation.lastpage","5423"],["dc.bibliographiccitation.volume","95"],["dc.contributor.author","Salonikidis, Petrus S."],["dc.contributor.author","Zeug, Andre"],["dc.contributor.author","Kobe, Fritz"],["dc.contributor.author","Ponimaskin, Evgeni G."],["dc.contributor.author","Richter, Diethelm W."],["dc.date.accessioned","2018-11-07T11:08:21Z"],["dc.date.available","2018-11-07T11:08:21Z"],["dc.date.issued","2008"],["dc.description.abstract","Forster resonance energy transfer (FRET)-based biosensors for the quantitative analysis of intracellular signaling, including sensors for monitoring cyclic adenosine monophosphate (cAMP), are of increasing interest. The measurement of the donor/acceptor emission ratio in tandem biosensors excited at the donor excitation wavelength is a commonly used technique. A general problem, however, is that this ratio varies not only with the changes in cAMP concentration but also with the changes of the ionic environment or other factors affecting the folding probability of the fluorophores. Here, we use a spectral FRET analysis on the basis of two excitation wavelengths to obtain a reliable measure of the absolute cAMP concentrations with high temporal and spatial resolution by using an \"exchange protein directly activated by cAMP\". In this approach, FRET analysis is simplified and does not require additional calibration routines. The change in FRET efficiency (E) of the biosensor caused by [cAMP] changes was determined as Delta E=15%, whereas E varies between 35% at low and 20% at high [cAMP], allowing quantitative measurement of cAMP concentration in the range from 150 nM to 15 mu M. The method described is also suitable for other FRET-based biosensors with a 1: 1 donor/acceptor stoichiometry. As a proof of principle, we measured the specially resolved cAMP concentration within living cells and determined the dynamic changes of cAMP levels after stimulation of the Gs-coupled serotonin receptor subtype 7 (5-HT7)."],["dc.identifier.doi","10.1529/biophysj.107.125666"],["dc.identifier.isi","000260999500039"],["dc.identifier.pmid","18708470"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/7766"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/52756"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Biophysical Soc"],["dc.relation.issn","0006-3495"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","Quantitative Measurement of cAMP Concentration Using an Exchange Protein Directly Activated by a cAMP-Based FRET-Sensor"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]
    Details DOI PMID PMC WOS
  • 2008Journal Article
    [["dc.bibliographiccitation.firstpage","1503"],["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","Biochimica et Biophysica Acta (BBA) - Molecular Cell Research"],["dc.bibliographiccitation.lastpage","1516"],["dc.bibliographiccitation.volume","1783"],["dc.contributor.author","Kobe, Fritz"],["dc.contributor.author","Renner, Ute"],["dc.contributor.author","Woehler, Andrew"],["dc.contributor.author","Wlodarczyk, Jakub"],["dc.contributor.author","Papusheva, Ekaterina"],["dc.contributor.author","Bao, Guobin"],["dc.contributor.author","Zeug, Andre"],["dc.contributor.author","Richter, Diethelm W."],["dc.contributor.author","Neher, Erwin"],["dc.contributor.author","Ponimaskin, Evgeni G."],["dc.date.accessioned","2018-11-07T11:12:17Z"],["dc.date.available","2018-11-07T11:12:17Z"],["dc.date.issued","2008"],["dc.description.abstract","In the present study we analyzed the oligomerization state of the serotonin 5-HT1A receptor and studied oligomerization dynamics in living cells. We also investigated the role of receptor palmitoylation in this process. Biochemical analysis performed in neuroblastoma N1E-115 cells demonstrated that both palmitoylated and non-palmitoylated 5-HT1A receptors form homo-oligomers and that the prevalent receptor species at the plasma membrane are dimers. A combination of an acceptor-photobleaching FRET approach with fluorescence lifetime measurements verified the interaction of CFP- and YFP-labeled wild-type as well as acylation-deficient 5-HT1A receptors at the plasma membrane of living cells. Using a novel FRET technique based on the spectral analysis we also confirmed the specific nature of receptor oligomerization. The analysis of oligomerization dynamics revealed that apparent FRET efficiency measured for wild-type oligomers significantly decreased in response to agonist stimulation, and our combined results suggest that this decrease was mediated by accumulation of FRET-negative complexes rather than by dissociation of oligomers to monomers. In contrast, the agonist-mediated decrease of FRET signal was completely abolished in oligomers composed by non-palmitoylated receptor mutants, demonstrating the importance of palmitoylation in modulation of the structure of oligomers. (C) 2008 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.bbamcr.2008.02.021"],["dc.identifier.isi","000257641600004"],["dc.identifier.pmid","18381076"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/7758"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/53629"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","0167-4889"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","Stimulation- and palmitoylation-dependent changes in oligomeric conformation of serotonin 5-HT1A receptors"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]
    Details DOI PMID PMC WOS
  • 2008Journal Article
    [["dc.bibliographiccitation.firstpage","986"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Biophysical Journal"],["dc.bibliographiccitation.lastpage","1000"],["dc.bibliographiccitation.volume","94"],["dc.contributor.author","Wlodarczyk, Jakub"],["dc.contributor.author","Woehler, Andrew"],["dc.contributor.author","Kobe, Fritz"],["dc.contributor.author","Ponimaskin, Evgeni G."],["dc.contributor.author","Zeug, Andre"],["dc.contributor.author","Neher, Erwin"],["dc.date.accessioned","2018-11-07T11:18:28Z"],["dc.date.available","2018-11-07T11:18:28Z"],["dc.date.issued","2008"],["dc.description.abstract","A method for spectral analysis of Forster resonance energy transfer (FRET) signals is presented, taking into consideration both the contributions of unpaired donor and acceptor fluorophores and the in fluence of incomplete labeling of the interacting partners. It is shown that spectral analysis of intermolecular FRET cannot yield accurate values of the Forster energy transfer efficiency E, unless one of the interactors is in large excess and perfectly labeled. Instead, analysis of donor quenching yields a product of the form Ef(d)p(a), where f(d) is the fraction of donor-type molecules participating in donor-acceptor complexes and p(a) is the labeling probability of the acceptor. Similarly, analysis of sensitized emission yields a product involving Ef(a). The analysis of intramolecular FRET (e. g., of tandem constructs) yields the product Ep(a). We use our method to determine these values for a tandem construct of cyan fluorescent protein and yellow fluorescent protein and compare them with those obtained by standard acceptor photobleaching and fluorescence lifetime measurements. We call the method lux-FRET, since it relies on linear unmixing of spectral components."],["dc.identifier.doi","10.1529/biophysj.107.111773"],["dc.identifier.isi","000252243200025"],["dc.identifier.pmid","17921223"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/7747"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/55040"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Cell Press"],["dc.relation.issn","0006-3495"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","Analysis of FRET signals in the presence of free donors and acceptors"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]
    Details DOI PMID PMC WOS