Gustavo Chaves,
Artem G. Ayuyan,
Vladimir V. Cherny,
Deri Morgan,
Arne Franzen,
Lynne Fieber,
Prof. Dr. Lydia Nausch,
Christian Derst,
Iryna Mahorivska,
Christophe Jardin,
Thomas E. DeCoursey,
Boris Musset
Thomas Bertsch,
Jochen Lüdecke,
Prof. Dr. Lydia Nausch,
Karl Landsteiner
Berechtigungen: Peer Reviewed
Karl Landsteiner: The Discovery of the ABO Blood Group System and its Value for Teaching Medical Students (2019) Clinical Laboratory 65 (6).
DOI: 10.7754/Clin.Lab.2018.181218
With his discovery of the ABO blood group system, Karl Landsteiner laid the foundation for modern day transfusion medicine. This discovery represents the basic knowledge for every blood transfusion. In recent years, certain blood groups have been linked to an increased risk for certain diseases. Hence, teaching the blood group serology is a relevant issue in medical education. In this review, we report about the history of the discovery of the blood groups by Landsteiner, the link of different blood groups to certain diseases and our experiences regarding teaching to medical students.
Thomas M. Moon,
Jessica L. Sheehe,
Praveena Nukareddy,
Prof. Dr. Lydia Nausch,
Jessica Wohlfahrt,
Dwight E. Matthews,
Donald K. Blumenthal,
Wolfgang R. Dostmann
Berechtigungen: Open Access
Berechtigungen: Peer Reviewed
An N-terminally truncated form of cyclic GMP-dependent protein kinase Iα (PKG Iα) is monomeric, autoinhibited, and provides a model for activation (2018) Journal of Biological Chemistry 293 (21), S. 7916-7929.
DOI: 10.1074/jbc.RA117.000647
The type I cGMP-dependent protein kinases (PKG I) serve essential physiological functions, including smooth muscle relaxation, cardiac remodeling, and platelet aggregation. These enzymes form homodimers through their N-terminal dimerization domains, a feature implicated in regulating their cooperative activation. Previous investigations into the activation mechanisms of PKG I isoforms have been largely influenced by structures of the cAMP-dependent protein kinase (PKA). Here, we examined PKG Iα activation by cGMP and cAMP by engineering a monomeric form that lacks N-terminal residues 1-53 (Δ53). We found that the construct exists as a monomer as assessed by whole-protein MS, size-exclusion chromatography, and small-angle X-ray scattering (SAXS). Reconstruction of the SAXS 3D envelope indicates that Δ53 has a similar shape to the heterodimeric RIα-C complex of PKA. Moreover, we found that the Δ53 construct is autoinhibited in its cGMP-free state and can bind to and be activated by cGMP in a manner similar to full-length PKG Iα as assessed by surface plasmon resonance (SPR) spectroscopy. However, we found that the Δ53 variant does not exhibit cooperative activation, and its cyclic nucleotide selectivity is diminished. These findings support a model in which, despite structural similarities, PKG Iα activation is distinct from that of PKA, and its cooperativity is driven by in trans interactions between protomers.
Qin Yang,
Prof. Dr. Lydia Nausch,
Georges Martin,
Walter Keller,
Sylvie Doublié
Berechtigungen: Peer Reviewed
Crystal structure of human poly(A) polymerase gamma reveals a conserved catalytic core for canonical poly(A) polymerases (2013) Journal of Molecular Biology 426 (1), S. 43-50.
DOI: 10.1016/j.jmb.2013.09.025
In eukaryotes, the poly(A) tail added at the 3′ end of a mRNA precursor is essential for the regulation of mRNA stability and the initiation of translation. Poly(A) polymerase (PAP) is the enzyme that catalyzes the poly(A) addition reaction. Multiple isoforms of PAP have been identified in vertebrates, which originate from gene duplication, alternative splicing, or post-translational modifications. The complexity of PAP isoforms suggests that they might play different roles in the cell. Phylogenetic studies indicate that vertebrate PAPs are grouped into three clades termed α, β and γ, which originated from two gene duplication events. To date, all the available PAP structures are from the PAPα clade. Here, we present the crystal structure of the first representative of the PAPγ clade, human PAPγ, bound to cordycepin triphosphate (3′dATP) and Ca2+. The structure revealed that PAPγ closely resembles its PAPα ortholog. An analysis of residue conservation reveals a conserved catalytic binding pocket, whereas residues at the surface of the polymerase are more divergent.
Prof. Dr. Lydia Nausch,
Adrian D. Bonev,
Thomas J. Heppner,
Yvonne Tallini,
Michael I. Kotlikoff,
Mark T. Nelson
Berechtigungen: Open Access
Berechtigungen: Peer Reviewed
Sympathetic nerve stimulation induces local endothelial Ca2+ signals to oppose vasoconstriction of mouse mesenteric arteries (2012) American Journal of Physiology: Heart and Circulatory Physiology 302 (3), S. H594-H602.
DOI: 10.1152/ajpheart.00773.2011
Prof. Dr. Lydia Nausch,
Adrian D. Bonev,
Yvonne Tallini,
Michael I. Kotlikoff,
Mark T. Nelson
Berechtigungen: Peer Reviewed
Nerve-induced smooth muscle to endothelium signaling in small resistance arteries (2010) THE FASEB JOURNAL 24 (S1), S. 598.7.
DOI: 10.1096/fasebj.24.1_supplement.598.7
Prof. Dr. Lydia Nausch,
Jonathan Ledoux,
Adrian D. Bonev,
Mark T. Nelson,
Wolfgang R. Dostmann
Berechtigungen: Peer Reviewed
Differential patterning of cGMP in vascular smooth muscle cells revealed by single GFP-linked biosensors (2008) PNAS 105 (1), S. 365–370.
DOI: 10.1073/pnas.0710387105
Here, we report the design of unprecedented, non-FRET based cGMP-biosensors, named FlincGs, to assess the dynamics of nitric oxide (NO) and atrial natriuretic peptide (ANP) induced synthesis of intracellular cGMP, [cGMP](i). Regulatory fragments of PKG I alpha, PKG I beta, and an N-terminal deletion mutant of PKG I alpha were fused to circular permutated EGFP to generate alpha-, beta-, and delta-FlincG, with high dynamic ranges and apparent K(D,cGMP) values of 35 nM, 1.1 microM, and 170 nM, respectively. All indicators displayed significant selectivity for cGMP over cAMP, and 1.5- to 2.1-fold increases in fluorescence intensity at 510 nm when excited at 480 nm. Surprisingly, FlincGs displayed an additional excitation peak at 410 nm. delta-FlincG permitted ratiometric (480/410 nm) measurements, with a cGMP-specific 3.5-fold ratio change. In addition, delta-FlincG presented cGMP association and dissociation kinetics sufficiently fast to monitor rapid changes of [cGMP](i) in intact cells. In unpassaged, adenoviral transfected vascular smooth muscle (VSM) cells, delta-FlincG had an EC(50,cGMP) of 150 nM, and revealed transient global cGMP elevations to sustained physiological NO (EC(50,DEA/NO) = 4 nM), and the decay phase depended on the activity of PDE-5. In contrast, ANP elicited sustained submembrane elevations in [cGMP](i), which were converted to global cGMP elevations by inhibition of PDE-5 by sildenafil. These results indicate that FlincG is an innovative tool to elucidate the dynamics of a central biological signal, cGMP, and that NO and natriuretic peptides induce distinct cGMP patterning under the regulation of PDE-5, and therefore likely differentially engage cGMP targets.
Prof. Dr. Lydia Nausch,
Wolfgang R. Dostmann
Berechtigungen: Open Access
Berechtigungen: Peer Reviewed
FlincGs: novel, non-FRET cGMP biosensors with nanomolar sensitivity for NO-induced signaling (2007) BMC Pharmacology 7 (S1), S. 1.
DOI: 10.1186/1471-2210-7-S1-S22
Here, we report the design of unprecedented, non-FRET based cGMP-biosensors, named FlincGs, to assess the dynamics of nitric oxide (NO) and atrial natriuretic peptide (ANP) induced synthesis of intracellular cGMP, [cGMP]i. Regulatory fragments of PKG I α, PKG I β, and an N-terminal deletion mutant of PKG I α were fused to circular permutated EGFP to generate α-, β-, and δ-FlincG, with high dynamic ranges and apparent KD,cGMP values of 35 nM, 1.1 μM, and 170 nM, respectively. All indicators displayed significant selectivity for cGMP over cAMP, and 1.5- to 2.1-fold increases in fluorescence intensity at 510 nm when excited at 480 nm. Surprisingly, FlincGs displayed an additional excitation peak at 410 nm. δ-FlincG permitted ratiometric (480/410 nm) measurements, with a cGMP-specific 3.5-fold ratio change. In addition, δ-FlincG presented cGMP association and dissociation kinetics sufficiently fast to monitor rapid changes of [cGMP]i in intact cells. In unpassaged, adenoviral transfected vascular smooth muscle (VSM) cells, δ-FlincG had an EC50,cGMP of 150 nM, and revealed transient global cGMP elevations to sustained physiological NO (EC50,DEA/NO = 4 nM), and the decay phase depended on the activity of PDE-5. In contrast, ANP elicited sustained submembrane elevations in [cGMP]i, which were converted to global cGMP elevations by inhibition of PDE-5 by sildenafil. These results indicate that FlincG is an innovative tool to elucidate the dynamics of a central biological signal, cGMP, and that NO and natriuretic peptides induce distinct cGMP patterning under the regulation of PDE-5, and therefore likely differentially engage cGMP targets.
C. Griesbeck,
M. Schutz,
T. Schodl,
S. Bathe,
Prof. Dr. Lydia Nausch,
N. Mederer,
M. Vielreicher,
G. Hauska
Berechtigungen: Peer Reviewed
Mechanism of Sulfide-Quinone Reductase Investigated Using Site-Directed Mutagenesis and Sulfur Analysis (2002) Biochemistry 41 (39), S. 11552-11565.
DOI: 10.1021/bi026032b
Biological sulfide oxidation is a reaction occurring in all three domains of life. One enzyme responsible for this reaction in many bacteria has been identified as sulfide:quinone oxidoreductase (SQR). The enzyme from Rhodobacter capsulatus is a peripherally membrane-bound flavoprotein with a molecular mass of approximately 48 kDa, presumably acting as a homodimer. In this work, SQR from Rb. capsulatus has been modified with an N-terminal His tag and heterologously expressed in and purified from Escherichia coli. Three cysteine residues have been shown to be essential for the reductive half-reaction by site-directed mutagenesis. The catalytic activity has been nearly completely abolished after mutation of each of the cysteines to serine. A decrease in fluorescence on reduction by sulfide as observed for the wild-type enzyme has not been observed for any of the mutated enzymes. Mutation of a conserved valine residue to aspartate within the third flavin-binding domain led to a drastically reduced substrate affinity, for both sulfide and quinone. Two conserved histidine residues have been mutated individually to alanine. Both of the resulting enzymes exhibited a shift in the pH dependence of the SQR reaction. Polysulfide has been identified as a primary reaction product using spectroscopic and chromatographic methods. On the basis of these data, reaction mechanisms for sulfide-dependent reduction and quinone-dependent oxidation of the enzyme and for the formation of polysulfide are proposed.
Beiträge zu wissenschaftlicher Konferenz/Tagung
Michael Maier,
M. R. Piqué-Borràs,
Sebastian Schmelzer,
Dr. Johann Röhrl,
Prof. Dr. Lydia Nausch
Gustavo Chaves,
Artem G. Ayuyan,
Vladimir V. Cherny,
Deri Morgan,
Arne Franzen,
Lynne Fieber,
Prof. Dr. Lydia Nausch,
Christian Derst,
Iryna Mahorivska,
Christophe Jardin,
Thomas E. DeCoursey,
Boris Musset
Voltage-gated ion channels, whose first identified function was to generate action potentials, are divided into subfamilies with numerous members. The family of voltage-gated proton channels (HV ) is tiny. To date, all species found to express HV , have exclusively one gene that codes for this unique ion channel. Here we report the discovery and characterization of three proton channel genes in the classical model system of neural plasticity, Aplysia californica. The three channels (AcHV1, AcHV2, AcHV3) are distributed throughout the whole animal. Patch-clamp analysis confirmed proton selectivity of these channels but they all differed markedly in gating. AcHV1 gating resembled HV in mammalian channels where it is responsible for proton extrusion and charge compensation. AcHV2 activates more negatively and conducts extensive inward proton current, properties likely to acidify the cytosol. AcHV3, which differs from AcHV1 and AcHV2 in lacking the first arginine in the S4 helix, exhibits proton selective leak currents and weak voltage dependence. We report the expansion of the proton channel family, demonstrating for the first time the expression of three functionally distinct proton channels in a single species.
Mehr
L. Ebert,
Sebastian Schmelzer,
Prof. Dr. Lydia Nausch
Novel Insights into PKG Activation and cGMP Signaling in Response to Nitric Oxide and Atrial Natriuretic Peptide in Vascular Smooth Muscle Cells (2008) (2008). Graduate College Dissertations and Theses. 158 .
Ziel dieses Forschungsprojekts ist es, pflanzliche Wirkstoffe unterschiedlicher Arzneimittel von Weleda zur Behandlung von Verdauungsproblemen hinsichtlich deren Einfluss auf typische mikrobiotische …
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