TY  - JOUR
A1  - Bensaad, Karim
A1  - Favaro, Elena
A1  - Lewis, Caroline A.
A1  - Peck, Barrie
A1  - Lord, Simon
A1  - Collins, Jennifer M.
A1  - Pinnick, Katherine E.
A1  - Wigfield, Simon
A1  - Buffa, Francesca M.
A1  - Li, Ji-Liang
A1  - Zhang, Qifeng
A1  - Wakelam, Michael J. O.
A1  - Karpe, Fredrik
A1  - Schulze, Almut
A1  - Harris, Adrian L.
T1  - Fatty Acid Uptake and Lipid Storage Induced by HIF-1 alpha Contribute to Cell Growth and Survival after Hypoxia-Reoxygenation
JF  - Cell Reports
N2  - An in vivo model of antiangiogenic therapy allowed us to identify genes upregulated by bevacizumab treatment, including Fatty Acid Binding Protein 3 (FABP3) and FABP7, both of which are involved in fatty acid uptake. In vitro, both were induced by hypoxia in a hypoxia-inducible factor-1 alpha (HIF-1 alpha)-dependent manner. There was a significant lipid droplet (LD) accumulation in hypoxia that was time and O-2 concentration dependent. Knockdown of endogenous expression of FABP3, FABP7, or Adipophilin (an essential LD structural component) significantly impaired LD formation under hypoxia. We showed that LD accumulation is due to FABP3/7-dependent fatty acid uptake while de novo fatty acid synthesis is repressed in hypoxia. We also showed that ATP production occurs via beta-oxidation or glycogen degradation in a cell-type-dependent manner in hypoxia-reoxygenation. Finally, inhibition of lipid storage reduced protection against reactive oxygen species toxicity, decreased the survival of cells subjected to hypoxia-reoxygenation in vitro, and strongly impaired tumorigenesis in vivo.
KW  - inducible factor-I
KW  - binding protein
KW  - triglyceride accumulation
KW  - cancer cell
KW  - complex-III
KW  - beta-oxidation
KW  - metabolism
KW  - lipogenesis
KW  - proliferation
KW  - resistance
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-115162
SN  - 2211-1247
VL  - 9
IS  - 1
ER  - 
TY  - JOUR
A1  - Akhoon, Bashir A.
A1  - Singh, Krishna P.
A1  - Varshney, Megha
A1  - Gupta, Shishir K.
A1  - Shukla, Yogeshwar
A1  - Gupta, Shailendra K.
T1  - Understanding the Mechanism of Atovaquone Drug Resistance in Plasmodium falciparum Cytochrome b Mutation Y268S Using Computational Methods
JF  - PLOS ONE
N2  - The rapid appearance of resistant malarial parasites after introduction of atovaquone (ATQ) drug has prompted the search for new drugs as even single point mutations in the active site of Cytochrome b protein can rapidly render ATQ ineffective. The presence of Y268 mutations in the Cytochrome b (Cyt b) protein is previously suggested to be responsible for the ATQ resistance in Plasmodium falciparum (P. falciparum). In this study, we examined the resistance mechanism against ATQ in P. falciparum through computational methods. Here, we reported a reliable protein model of Cyt bc1 complex containing Cyt b and the Iron-Sulphur Protein (ISP) of P. falciparum using composite modeling method by combining threading, ab initio modeling and atomic-level structure refinement approaches. The molecular dynamics simulations suggest that Y268S mutation causes ATQ resistance by reducing hydrophobic interactions between Cyt bc1 protein complex and ATQ. Moreover, the important histidine contact of ATQ with the ISP chain is also lost due to Y268S mutation. We noticed the induced mutation alters the arrangement of active site residues in a fashion that enforces ATQ to find its new stable binding site far away from the wild-type binding pocket. The MM-PBSA calculations also shows that the binding affinity of ATQ with Cyt bc1 complex is enough to hold it at this new site that ultimately leads to the ATQ resistance.
KW  - molecular-dynamics simulations
KW  - HIV-1 protease
KW  - structure prediction
KW  - saccharomyces cerevisiae
KW  - I-tasser
KW  - inhibitors
KW  - binding
KW  - malaria
KW  - complex
KW  - protein-protein interactions
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-114882
VL  - 9
IS  - 10
ER  - 
TY  - JOUR
A1  - Senecal, Jean-Luc
A1  - Isabelle, Catherine
A1  - Fritzler, Marvin J.
A1  - Targoff, Ira N.
A1  - Goldstein, Rose
A1  - Gagne, Michel
A1  - Raynauld, Jean-Pierre
A1  - Joyal, France
A1  - Troyanov, Yves
A1  - Dabauvalle, Marie-Christine
T1  - An Autoimmune Myositis-Overlap Syndrome Associated With Autoantibodies to Nuclear Pore Complexes Description and Long-Term Follow-up of the Anti-Nup Syndrome
JF  - Medicine
N2  - Autoimmune myositis encompasses various myositis-overlap syndromes, each being identified by the presence of serum marker autoantibodies. We describe a novel myositis-overlap syndrome in 4 patients characterized by the presence of a unique immunologic marker, autoantibodies to nuclear pore complexes. The clinical phenotype was characterized by prominent myositis in association with erosive, anti-CCP, and rheumatoid factor-positive arthritis, trigeminal neuralgia, mild interstitial lung disease, Raynaud phenomenon, and weight loss. The myositis was typically chronic, relapsing, and refractory to corticosteroids alone, but remitted with the addition of a second immuno-modulating drug. There was no clinical or laboratory evidence for liver disease. The prognosis was good with 100% long-term survival (mean follow-up 19.5 yr). By indirect immunofluorescence on HEp-2 cells, sera from all 4 patients displayed a high titer of antinuclear autoantibodies (ANA) with a distinct punctate peripheral (rim) fluorescent pattern of the nuclear envelope characteristic of nuclear pore complexes. Reactivity with nuclear pore complexes was confirmed by immunoelectron microscopy. In a cohort of 100 French Canadian patients with autoimmune myositis, the nuclear pore complex fluorescent ANA pattern was restricted to these 4 patients (4%). It was not observed in sera from 393 adult patients with systemic sclerosis (n = 112), mixed connective tissue disease (n = 35), systemic lupus (n = 94), rheumatoid arthritis (n = 45), or other rheumatic diseases (n = 107), nor was it observed in 62 normal adults. Autoantibodies to nuclear pore complexes were predominantly of IgG isotype. No other IgG autoantibody markers for defined connective tissue diseases or overlap syndromes were present, indicating a selective and highly focused immune response. In 3 patients, anti-nuclear pore complex autoantibody titers varied in parallel with myositis activity, suggesting a pathogenic link to pathophysiology. The nuclear pore complex proteins, that is, nucleoporins (nup), recognized by these sera were heterogeneous and included Nup358/RanBP2 (n = 2 patients), Nup90 (n = 1), Nup62 (n = 1), and gp210 (n = 1). Taken together the data suggest that nup autoantigens themselves drive the anti-nup autoimmune response. Immunogenetically, the 4 patients shared the DQA1*0501 allele associated with an increased risk for autoimmune myositis. In conclusion, we report an apparent novel subset of autoimmune myositis in our population of French Canadian patients with connective tissue diseases. This syndrome is recognized by the presence of a unique immunologic marker, autoantibodies to nuclear pore complexes that react with nups, consistent with an "anti-nupsyndrome.''
KW  - idiopathic inflammatory myopathies
KW  - primary biliary-cirrhosis
KW  - transfer RNA-synthetases
KW  - major histocompatibility complex
KW  - systemic sclerosis
KW  - French-Canadian patients
KW  - protein
KW  - predictive factors
KW  - envelope
KW  - antibodies
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-114829
SN  - 0025-7974
VL  - 93
IS  - 24
ER  - 
TY  - JOUR
A1  - Hudson, Lawrence N.
A1  - Newbold, Tim
A1  - Contu, Sara
A1  - Hill, Samantha L. L.
A1  - Lysenko, Igor
A1  - De Palma, Adriana
A1  - Phillips, Helen R. P.
A1  - Senior, Rebecca A.
A1  - Bennett, Dominic J.
A1  - Booth, Hollie
A1  - Choimes, Argyrios
A1  - Correia, David L. P.
A1  - Day, Julie
A1  - Echeverria-Londono, Susy
A1  - Garon, Morgan
A1  - Harrison, Michelle L. K.
A1  - Ingram, Daniel J.
A1  - Jung, Martin
A1  - Kemp, Victoria
A1  - Kirkpatrick, Lucinda
A1  - Martin, Callum D.
A1  - Pan, Yuan
A1  - White, Hannah J.
A1  - Aben, Job
A1  - Abrahamczyk, Stefan
A1  - Adum, Gilbert B.
A1  - Aguilar-Barquero, Virginia
A1  - Aizen, Marcelo
A1  - Ancrenaz, Marc
A1  - Arbelaez-Cortes, Enrique
A1  - Armbrecht, Inge
A1  - Azhar, Badrul
A1  - Azpiroz, Adrian B.
A1  - Baeten, Lander
A1  - Báldi, András
A1  - Banks, John E.
A1  - Barlow, Jos
A1  - Batáry, Péter
A1  - Bates, Adam J.
A1  - Bayne, Erin M.
A1  - Beja, Pedro
A1  - Berg, Ake
A1  - Berry, Nicholas J.
A1  - Bicknell, Jake E.
A1  - Bihn, Jochen H.
A1  - Böhning-Gaese, Katrin
A1  - Boekhout, Teun
A1  - Boutin, Celine
A1  - Bouyer, Jeremy
A1  - Brearley, Francis Q.
A1  - Brito, Isabel
A1  - Brunet, Jörg
A1  - Buczkowski, Grzegorz
A1  - Buscardo, Erika
A1  - Cabra-Garcia, Jimmy
A1  - Calvino-Cancela, Maria
A1  - Cameron, Sydney A.
A1  - Cancello, Eliana M.
A1  - Carrijo, Tiago F.
A1  - Carvalho, Anelena L.
A1  - Castro, Helena
A1  - Castro-Luna, Alejandro A.
A1  - Cerda, Rolando
A1  - Cerezo, Alexis
A1  - Chauvat, Matthieu
A1  - Clarke, Frank M.
A1  - Cleary, Daniel F. R.
A1  - Connop, Stuart P.
A1  - D'Aniello, Biagio
A1  - da Silva, Pedro Giovani
A1  - Darvill, Ben
A1  - Dauber, Jens
A1  - Dejean, Alain
A1  - Diekötter, Tim
A1  - Dominguez-Haydar, Yamileth
A1  - Dormann, Carsten F.
A1  - Dumont, Bertrand
A1  - Dures, Simon G.
A1  - Dynesius, Mats
A1  - Edenius, Lars
A1  - Elek, Zoltán
A1  - Entling, Martin H.
A1  - Farwig, Nina
A1  - Fayle, Tom M.
A1  - Felicioli, Antonio
A1  - Felton, Annika M.
A1  - Ficetola, Gentile F.
A1  - Filgueiras, Bruno K. C.
A1  - Fonte, Steve J.
A1  - Fraser, Lauchlan H.
A1  - Fukuda, Daisuke
A1  - Furlani, Dario
A1  - Ganzhorn, Jörg U.
A1  - Garden, Jenni G.
A1  - Gheler-Costa, Carla
A1  - Giordani, Paolo
A1  - Giordano, Simonetta
A1  - Gottschalk, Marco S.
A1  - Goulson, Dave
A1  - Gove, Aaron D.
A1  - Grogan, James
A1  - Hanley, Mick E.
A1  - Hanson, Thor
A1  - Hashim, Nor R.
A1  - Hawes, Joseph E.
A1  - Hébert, Christian
A1  - Helden, Alvin J.
A1  - Henden, John-André
A1  - Hernández, Lionel
A1  - Herzog, Felix
A1  - Higuera-Diaz, Diego
A1  - Hilje, Branko
A1  - Horgan, Finbarr G.
A1  - Horváth, Roland
A1  - Hylander, Kristoffer
A1  - Horváth, Roland
A1  - Isaacs-Cubides, Paola
A1  - Ishitani, Mashiro
A1  - Jacobs, Carmen T.
A1  - Jaramillo, Victor J.
A1  - Jauker, Birgit
A1  - Jonsell, Matts
A1  - Jung, Thomas S.
A1  - Kapoor, Vena
A1  - Kati, Vassiliki
A1  - Katovai, Eric
A1  - Kessler, Michael
A1  - Knop, Eva
A1  - Kolb, Annette
A1  - Körösi, Àdám
A1  - Lachat, Thibault
A1  - Lantschner, Victoria
A1  - Le Féon, Violette
A1  - LeBuhn, Gretchen
A1  - Légaré, Jean-Philippe
A1  - Letcher, Susan G.
A1  - Littlewood, Nick A.
A1  - López-Quintero, Carlos A.
A1  - Louhaichi, Mounir
A1  - Lövei, Gabor L.
A1  - Lucas-Borja, Manuel Esteban
A1  - Luja, Victor H.
A1  - Maeto, Kaoru
A1  - Magura, Tibor
A1  - Mallari, Neil Aldrin
A1  - Marin-Spiotta, Erika
A1  - Marhall, E. J. P.
A1  - Martínez, Eliana
A1  - Mayfield, Margaret M.
A1  - Mikusinski, Gregorz
A1  - Milder, Jeffery C.
A1  - Miller, James R.
A1  - Morales, Carolina L.
A1  - Muchane, Mary N.
A1  - Muchane, Muchai
A1  - Naidoo, Robin
A1  - Nakamura, Akihiro
A1  - Naoe, Shoji
A1  - Nates-Parra, Guiomar
A1  - Navarerete Gutierrez, Dario A.
A1  - Neuschulz, Eike L.
A1  - Noreika, Norbertas
A1  - Norfolk, Olivia
A1  - Noriega, Jorge Ari
A1  - Nöske, Nicole M.
A1  - O'Dea, Niall
A1  - Oduro, William
A1  - Ofori-Boateng, Caleb
A1  - Oke, Chris O.
A1  - Osgathorpe, Lynne M.
A1  - Paritsis, Juan
A1  - Parrah, Alejandro
A1  - Pelegrin, Nicolás
A1  - Peres, Carlos A.
A1  - Persson, Anna S.
A1  - Petanidou, Theodora
A1  - Phalan, Ben
A1  - Philips, T. Keith
A1  - Poveda, Katja
A1  - Power, Eileen F.
A1  - Presley, Steven J.
A1  - Proença, Vânia
A1  - Quaranta, Marino
A1  - Quintero, Carolina
A1  - Redpath-Downing, Nicola A.
A1  - Reid, J. Leighton
A1  - Reis, Yana T.
A1  - Ribeiro, Danilo B.
A1  - Richardson, Barbara A.
A1  - Richardson, Michael J.
A1  - Robles, Carolina A.
A1  - Römbke, Jörg
A1  - Romero-Duque, Luz Piedad
A1  - Rosselli, Loreta
A1  - Rossiter, Stephen J.
A1  - Roulston, T'ai H.
A1  - Rousseau, Laurent
A1  - Sadler, Jonathan P.
A1  - Sáfián, Szbolcs
A1  - Saldaña-Vásquez, Romeo A.
A1  - Samnegård, Ulrika
A1  - Schüepp, Christof
A1  - Schweiger, Oliver
A1  - Sedlock, Jodi L.
A1  - Shahabuddin, Ghazala
A1  - Sheil, Douglas
A1  - Silva, Fernando A. B.
A1  - Slade, Eleanor
A1  - Smith-Pardo, Allan H.
A1  - Sodhi, Navjot S.
A1  - Somarriba, Eduardo J.
A1  - Sosa, Ramón A.
A1  - Stout, Jane C.
A1  - Struebig, Matthew J.
A1  - Sung, Yik-Hei
A1  - Threlfall, Caragh G.
A1  - Tonietto, Rebecca
A1  - Tóthmérész, Béla
A1  - Tscharntke, Teja
A1  - Turner, Edgar C.
A1  - Tylianakis, Jason M.
A1  - Vanbergen, Adam J.
A1  - Vassilev, Kiril
A1  - Verboven, Hans A. F.
A1  - Vergara, Carlos H.
A1  - Vergara, Pablo M.
A1  - Verhulst, Jort
A1  - Walker, Tony R.
A1  - Wang, Yanping
A1  - Watling, James I.
A1  - Wells, Konstans
A1  - Williams, Christopher D.
A1  - Willig, Michael R.
A1  - Woinarski, John C. Z.
A1  - Wolf, Jan H. D.
A1  - Woodcock, Ben A.
A1  - Yu, Douglas W.
A1  - Zailsev, Andreys
A1  - Collen, Ben
A1  - Ewers, Rob M.
A1  - Mace, Georgina M.
A1  - Purves, Drew W.
A1  - Scharlemann, Jörn P. W.
A1  - Pervis, Andy
T1  - The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts
JF  - Ecology and Evolution
N2  - Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project - and avert - future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups - including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems - ). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.
KW  - urban-rural gradient
KW  - instensively managed farmland
KW  - Mexican coffee plantations
KW  - Bombus Spp. Hymenoptera
KW  - bumblebee nest density
KW  - data sharing
KW  - land use
KW  - habitat destruction
KW  - global change
KW  - land-use change
KW  - plant community composition
KW  - Northeastern Costa Rica
KW  - dung beetle coleoptera
KW  - bird species richness
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-114425
VL  - 4
IS  - 24
ER  - 
TY  - JOUR
A1  - Rozycka, Miroslawa
A1  - Wojtas, Magdalena
A1  - Jakob, Michal
A1  - Stigloher, Christian
A1  - Grzeszkowiak, Mikolaj
A1  - Mazur, Maciej
A1  - Ozyhar, Andrzej
T1  - Intrinsically Disordered and Pliable Starmaker-Like Protein from Medaka (Oryzias latipes) Controls the Formation of Calcium Carbonate Crystals
JF  - PLOS ONE
N2  - Fish otoliths, biominerals composed of calcium carbonate with a small amount of organic matrix, are involved in the functioning of the inner ear. Starmaker (Stm) from zebrafish (Danio rerio) was the first protein found to be capable of controlling the formation of otoliths. Recently, a gene was identified encoding the Starmaker-like (Stm-l) protein from medaka (Oryzias latipes), a putative homologue of Stm and human dentine sialophosphoprotein. Although there is no sequence similarity between Stm-l and Stm, Stm-l was suggested to be involved in the biomineralization of otoliths, as had been observed for Stm even before. The molecular properties and functioning of Stm-l as a putative regulatory protein in otolith formation have not been characterized yet. A comprehensive biochemical and biophysical analysis of recombinant Stm-l, along with in silico examinations, indicated that Stm-l exhibits properties of a coil-like intrinsically disordered protein. Stm-l possesses an elongated and pliable structure that is able to adopt a more ordered and rigid conformation under the influence of different factors. An in vitro assay of the biomineralization activity of Stm-l indicated that Stm-l affected the size, shape and number of calcium carbonate crystals. The functional significance of intrinsically disordered properties of Stm-l and the possible role of this protein in controlling the formation of calcium carbonate crystals is discussed.
KW  - circular-dichroism
KW  - unstructured proteins
KW  - olyelectrolyte domains
KW  - modulating
KW  - biominarlization proteins
KW  - nacreous layer formation
KW  - alpha-helical structure
KW  - dye stains-all
KW  - polyelectrolyte domains
KW  - phosphorylation sites
KW  - procambarus-clarkii
KW  - secondary structure
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-114251
SN  - 1932-6203
VL  - 9
IS  - 12
ER  - 
TY  - THES
A1  - Sibilski, Claudia
T1  - Identification and characterization of the novel mKSR1 phosphorylation site Tyr728 and its role in MAPK signaling
T1  - Identifizierung und Charakterisierung der neuartigen mKSR1-Phosphorylierungsstelle Tyr728 und deren Rolle in der MAPK-Signalkaskade
N2  - In mammals, KSR1 functions as an essential scaffold that coordinates the assembly of RAF/MEK/ERK complexes and regulates intracellular signal transduction upon extracellular stimulation. Aberrant activation of the equivalent MAPK signaling pathway has been implicated in multiple human cancers and some developmental disorders. The mechanism of KSR1 regulation is highly complex and involves several phosphorylation/dephosphorylation steps. In the present study, a number of novel in vivo phosphorylation sites were detected in mKSR1 by use of mass spectrometry analysis. Among others, Tyr728 was identified as a unique regulatory residue phosphorylated by LCK, a Src kinase family member. To understand how phosphorylation of Tyr728 may regulate the function of KSR1 in signal transduction and cellular processes, structural modeling and biochemical studies were integrated in this work.
Computational modeling of the mKSR1(KD) protein structure revealed strong hydrogen bonding between phospho-Tyr728 and the residues surrounding Arg649. Remarkably, this pattern was altered when Tyr728 was non-phosphorylated or substituted. As confirmed by biochemical analysis, Arg649 may serve as a major anchor point for phospho-Tyr728 in order to stabilize internal structures of KSR1. In line with the protein modeling results, mutational studies revealed that substitution of Tyr728 by phenylalanine leads to a less compact interaction between KSR1 and MEK, a facilitated KSR1/B-RAF binding and an increased phosphorylation of MEK in complex with KSR1. From these findings it can be concluded that phospho-Tyr728 is involved in tightening the KSR1/MEK interaction interface and in regulating the phosphorylation of KSR1-bound MEK by either RAF or KSR1 kinases.
Beside the Tyr728, Ser722 was identified as a novel regulatory phosphorylation site. Amino acid exchanges at the relevant position demonstrated that Ser722 regulates KSR1-bound MEK phosphorylation without affecting KSR1/MEK binding per se. Due to its localization, Ser722 might consequently control the catalytic activity of KSR1 by interfering with the access of substrate (possibly MEK) to the active site of KSR1 kinase. Together with Ser722, phosphorylated Tyr728 may further positively affect the kinase activity of KSR1 as a consequence of its vicinity to the activation and catalytic loop in the KSR1(KD). As revealed by structural modeling, phospho-Tyr728 builds a hydrogen bond with the highly conserved Lys685. Consequently, phospho-Tyr728 has a stabilizing effect on internal structures involved in the catalytic reaction and possibly enhances the phosphate transfer within the catalytic cleft in KSR1. Considering these facts, it seems very likely that the LCK-dependent phosphorylation of Tyr728 plays a crucial role in the regulation of KSR1 catalytic activity.
Results of fractionation and morphology analyses revealed that KSR1 recruits LCK to cytoskeleton for its phosphorylation at Tyr728 suggesting that this residue may regulate cytoskeleton dynamics and, consequently, cell motility. Beside that, phosphorylation of Tyr728 is involved in the regulation of cell proliferation, as shown by a significantly reduced population doubling time of KSR1-Y728F cells compared to cells expressing wild type KSR1.
Taken together, tyrosine phosphorylation in KSR1 uncovers a new link between Src family kinases and MAPK signaling. Tyr728, the novel regulatory phosphorylation site in murine KSR1, may coordinate the transition between the scaffolding and the catalytic function of KSR1 serving as a control point used to fine-tune cellular responses.
N2  - KSR1 fungiert bei Säugetieren als zentrales Gerüstprotein, welches die Anordnung von RAF/MEK/ERK-Komplexen koordiniert und die intrazelluläre Signalweiterleitung nach extrazellulärer Stimulation reguliert. Eine abweichende Aktivierung des entsprechenden MAPK-Signalwegs wurde mit vielen humanen Krebsformen und einigen Entwicklungsstörungen in Verbindung gebracht. Der Mechanismus der KSR1-Regulierung ist hochgradig komplex und involviert mehrfach Schritte der Phosphorylierung/Dephosphorylierung. In der vorliegenden Studie wurden etliche neue in-vivo-Phosphorylierungsstellen in mKSR1 mittels massenspektrometrischer Analyse entdeckt. Neben anderen wurde Tyr728 als besonderer regulatorischer Rest identifiziert, welcher durch LCK, einem Mitglied der Src-Kinase-Familie, phosphoryliert wird. Um zu verstehen wie die Phosphorylierung von Tyr728 die Funktion von KSR1 innerhalb der Signalweiterleitung und zellulärer Prozesse regulieren könnte, wurden strukturelle Modellierungen und biochemische Untersuchungen in diese Arbeit integriert.
Die Computermodellierung der mKSR1(KD)-Proteinstruktur zeigte starke Wasserstoff- brückenbindungen zwischen Phospho-Tyr728 und den Resten in der Umgebung von Arg649 auf. Dieses Muster war auffällig verändert, wenn Tyr728 nicht phosphoryliert oder substituiert war. Wie anhand biochemischer Analyse untermauert wurde, könnte Arg649 für phospho-Tyr728 als Hauptankerpunkt dienen, um interne Strukturen in KSR1 zu stabilisieren. In Übereinstimmung mit den Ergebnissen der Proteinmodellierung enthüllten die Mutationsstudien, dass die Substitution von Tyr728 mit Phenylalanin zu einer weniger kompakten Interaktion zwischen KSR1 und MEK, einer erleichterten KSR1/B-RAF-Bindung und einer ansteigenden Phosphorylierung von MEK im Komplex mit KSR1 führt. Anhand dieser Erkenntnisse kann man rückschließen, dass Phospho-Tyr728 in die Verstärkung der Interaktionen innerhalb der KSR1/MEK-Grenzfläche und in die Regulierung der Phosphorylierung von KSR1-gebundenem MEK durch entweder RAF- oder KSR1-Kinasen involviert ist.
Neben Tyr728 wurde Ser722 als eine neuartige regulatorische Phosphorylierungsstelle identifiziert. Aminosäureaustausche an der betreffenden Position demonstrierten, dass Ser722 die Phosphorylierung von KSR1-gebundenem MEK reguliert ohne die KSR1/MEK-Bindung selbst zu beeinträchtigen. Bedingt durch seine Lokalisierung könnte Ser722 folglich die katalytische Aktivität von KSR1 kontrollieren, indem es den Zugang des Substrates (möglicherweise MEK) zur aktiven Seite der KSR1-Kinase behindert. Zusammen mit Ser722 könnte phosphoryliertes Tyr728 ferner die Kinaseaktivität von KSR1 positiv beeinflussen, infolge von dessen Nähe zur Aktivierungs- und katalytischen Schleife in der KSR1(KD). Wie mittels Strukturmodellierung offengelegt wurde, bildet Phospho-Tyr728 eine Wasserstoffbrücke mit dem hochgradig konservierten Lys685 aus. Folglich hat Phospho-Tyr728 einen stabilisierenden Effekt auf interne Strukturen, welche in die katalytische Reaktion involviert sind, und erleichtert möglicherweise den Phosphattransfer innerhalb der katalytischen Spalte in KSR1. In Anbetracht dieser Fakten scheint es sehr wahrscheinlich, dass die LCK-abhängige Phosphorylierung von Tyr728 eine äußerst wichtige Rolle in der Regulierung der katalytischen Aktivität von KSR1 spielt.
Die Ergebnisse der Fraktionierungs- und Morphologieanalysen enthüllten, dass KSR1 für die Phosphorylierung an Tyr728 LCK zum Zytoskelett rekrutiert, was darauf hindeutet, dass dieser Rest die Dynamik des Zytoskeletts und folglich Zellmotilität regulieren könnte. Darüber hinaus ist die Phosphorylierung von Tyr728 in die Regulierung der Zellproliferation involviert, wie anhand einer bedeutend reduzierten Populationsverdopplungszeit von KSR1-Y728F-Zellen im Vergleich zu Zellen, welche wildtypisches KSR1 exprimieren, gezeigt wurde.
Zusammenfassend lässt sich sagen, dass die Tyrosin-Phosphorylierung in KSR1 eine neue Verknüpfung zwischen Kinasen der Src-Familie und der MAPK-Signalwirkung enthüllt. Tyr728, die neuartige regulatorische Phosphorylierungsstelle in Maus-KSR1, könnte den Übergang zwischen der Gerüst- und der katalytischen Funktion von KSR1 koordinieren und damit als Kontrollpunkt dienen, um zelluläre Reaktionen fein abzustimmen.
KW  - MAP-Kinase
KW  - Signaltransduktion
KW  - Regulation
KW  - tyrosine phosphorylation
KW  - KSR1
KW  - LCK
KW  - MAPK
KW  - phosphorylation
KW  - signaling
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-114672
ER  - 
TY  - THES
A1  - Wenzel, Jens
T1  - Regulation of TLR-induced macrophage responses by cytoskeleton-associated phosphoproteins
T1  - Regulation der Antwort von Makrophagen auf TLR-Stimulation durch Zytoskelett-assoziierte Phosphoproteine
N2  - Toll-like receptors (TLR) are pattern recognition receptors (PRR) by which macrophages (MØ) sense pathogen-associated molecular patterns (PAMPs). The recognition of lipopolysaccharide (LPS), the PAMP of gram negative bacteria, by TLR4 triggers signaling cascades and leads to the pro-inflammatory activation of the cells. A recent quantitative and kinetic analysis of the phosphoproteome of LPS-activated primary macrophages highlighted the cytoskeleton as a cell compartment with an enriched protein phosphorylation. In total 44 cytoskeleton-associated proteins were regulated by this post-translational modification and thus might be involved in the control and regulation of key macrophage functions like spreading, motility and phagocytosis. 
To investigate the control of cytoskeleton-associated cell functions by TLR4 activation, we first developed a method to quantitatively measure the spreading response of bone marrow MØ after stimulation with LPS. Fluorescence microscopy was used for cell imaging and visualisation of the MØ contact area. In collaboration with the Fraunhofer Institute Erlangen, we developed and validated a software tool for the semi-automated segmentation and quantitation of MØ fluorescence microscopy data, which allowed fast, robust and objective image analysis. Using this method, we observed that LPS caused time-dependent spreading, which was detectable after 1-2 h and maximal after 24 h. Next, the impact of genetic or pharmacological inhibition of known TLR signaling components was investigated. Deficiency in the adapter protein MYD88 strongly reduced spreading activity at the late time points, but had no impact early after LPS-stimulation. A similar effect was observed upon pharmacological inhibition of ERK1/2 signaling, indicating that ERK1/2 mediates MYD88-dependent MØ spreading. In contrast, MØ lacking the MAPK p38 were impaired in the initial spreading response but responded normally 8-24 h after stimulation. The genetic deletion of the MAPK phosphatases DUSP1 and DUSP16 resulted in impaired late spreading, corroborating the essential role for functional MAPK signaling in TLR4-driven MØ spreading. 
To identify the contribution of other cytoskeletal phosphoproteins to MØ spreading, siRNA knockdown of selected candidate genes in primary murine MØ was employed and combined with automated quantitative image analysis. These experiments revealed a functional role for the Myosins MYO1e and MYO1f in MØ spreading. These motor proteins are strongly phosphorylated in LPS-activated MØ. Because of their ability to simultaneously bind to actin filaments and cell membrane or other proteins, we investigated their role in phagocytosis, cytokine production and antigen presentation. Phagocytosis and killing of bacteria were not affected in Myo1e-/- macrophages. However, MYO1e plays a role in chemokine secretion and antigen presentation processes. MCP1 (CCL2) release was selectively increased in Myo1e-deficient MØ and dendritic cells (DC), while cytokine secretion was unaffected. Furthermore, macrophages and DCs lacking MYO1e showed lower levels of MHC-II on the cell surface. However, mRNA levels of CCL2 and of MHC-II were unaltered. These data suggest a role for MYO1e in the transport of selected chemokines and of MHC-II molecules to the cell surface. MHC-II-restricted antigen presentation assays revealed an impaired capacity of macrophages and DC lacking MYO1e to stimulate antigen-specific T cells, suggesting that the reduced MHC-II expression is functionally relevant.
Taken together, in this study first a quantitative image analysis method was developed which allows the unbiased, robust and efficient investigation of the macrophage spreading response. Combination of this method with siRNA knockdown of selected cytoskeleton-associated phosphoproteins led to the identification of MYO1e and MYO1f as regulators of macrophage spreading. Furthermore, we identified MYO1e in MØ and DC to be essential for the intracellular transport of CCL2 and MHC-II to the cell surface and for optimal stimulation of antigen-specific CD4 T cells.
N2  - Toll-like Rezeptoren (TLR) sind Mustererkennungsrezeptoren (PRR) durch die Makrophagen (MØ) pathogen-assoziierte molekulare Muster (PAMPs) erkennen. Die Erkennung von Lipopolysacchariden (LPS), dem PAMP gramnegativer Bakterien, durch TLR4 löst Signalkaskaden aus, die zu einer pro-inflammatorischen Aktivierung der Zellen führen. Eine quantitative und kinetische Analyse des Phosphoproteoms LPS-aktivierter primärer Makrophagen identifizierte das Zytoskelett als ein Zellkompartiment mit gesteigerter Proteinphosphorylierung. Insgesamt wurden 44 Zytoskelett-assoziierte Proteine identifiziert, die durch diese post-translationale Modifikation reguliert wurden und demzufolge an der Regulation wichtiger Zellfunktionen von Makrophagen wie Spreading, Motilität und Phagozytose beteiligt sein könnten. 
Um die Kontrolle Zytoskelett-vermittelter Zellfunktionen nach TLR4 Aktivierung zu untersuchen, entwickelten wir zunächst eine Methode zur quantitativen Messung der Spreadingantwort von Knochenmarksmakrophagen nach LPS Stimulation. Die Visualisierung der Zellen sowie ihrer Kontaktfläche erfolgte hierbei mittels Fluoreszenzmikroskopie. Für eine schnelle, robuste und objektive Analyse der Fluoreszenzaufnahmen entwickelten und validierten wir in Kollaboration mit dem Fraunhofer Institut in Erlangen eine Software zur halbautomatischen Segmentierung und Quantifizierung der Kontaktfläche. Unter Verwendung dieser Methode konnte eine zeitabhängige LPS-induzierte Zunahme der Zellkontaktfläche beobachtet werden, die nach 1-2 Stunden detektierbar war und ein Maximum nach 
24 Stunden erreichte. Durch den Einsatz pharmakologischer Inhibitoren sowie genetisch veränderter Zellen wurde anschließend der Einfluss bekannter TLR4-Signalwegkomponenten untersucht. Die genetische Defizienz des Adapterproteins MYD88 führte hierbei zu einer stark reduzierten Spreadingaktivität der Zellen während der späten LPS Stimulationsphase, wohingegen das initiale Spreading nicht beeinflusst wurde. Ein vergleichbarer Effekt konnte unter Verwendung eines pharmakologischen Inhibitors zur Hemmung des ERK1/2 Signalweges identifiziert werden. Diese Beobachtungen deuten darauf hin, dass ERK1/2 für die Weiterleitung des MYD88 vermittelten Spreading notwendig ist. Im Gegensatz dazu wurde in p38-defizienten Makrophagen ein beeinträchtigtes initiales Spreading beobachtet, wohingegen das späte Spreading nach 8 – 24 Stunden nicht beeinflusst war. Die genetische Deletion der MAPK Phosphatasen DUSP1 und DUSP16 resultierte ebenfalls in einer Minderung des späten Spreadings, ebenfalls ein Hinweis auf die essentielle Rolle funktioneller MAPK Signalwege. 
Um die Beteiligung weiter Zytoskelett-Phosphoproteine am Zellspreading zu identifizieren, wurde die Expression ausgewählter Kandidatengene in primären Makrophagen mittels spezifischer siRNA unterdrückt und das Zellspreading mit Hilfe der entwickelten Software quantifiziert. Diese Versuche zeigten eine funktionelle Rolle der Myosine MYO1e und MYO1f. Diese Motorproteine weisen ebenfalls eine starke Phosphorylierung nach LPS Stimulation auf. Aufgrund ihrer Eigenschaft simultan mit Aktinfilamenten und Zellmembranen sowie anderen Proteinen zu interagieren, untersuchten wir ihre Rolle während der Phagozytose, Zytokinfreisetzung und Antigenpräsentation. Obwohl Myo1e defiziente Makrophagen keine Beeinträchtigung der Phagozytose oder Abtötung von Bakterien aufwiesen, spielte das Motorprotein eine wichtige Rolle in der Chemokinfreisetzung und Antigenpräsentation. Interessanterweise war die Sekretion des Chemokins MCP1 (CCL2) in Myo1e-defizienten Makrophagen und dendritischen Zellen (DC) selektiv erhöht, während die Zytokinfreisetzung unbeeinträchtigt war. Des Weiteren wiesen Myo1e KO Makrophagen und DC eine reduzierte MHC-II Oberflächen-Expression auf, obwohl die MHC-II als auch die CCL2 Transkription auf mRNA Ebene nicht beeinflusst war. Diese Daten legen nahe, dass MYO1e während des Transports bestimmter Chemokine, sowie von MHC-II zur Zelloberfläche eine wichtige Rolle spielt. Zudem zeigten Myo1e KO Makrophagen und DC in einem MHC-II-abhängigen Antigenpräsentationsassay eine abgeschwächte Fähigkeit zur Antigen-spezifischen T-Zell Aktivierung, was die funktionelle Relevanz der reduzierten Expression von MHC-II nahelegt.
Zusammenfassend wurde in dieser Studie zunächst eine Methode zur quantitativen Bildanalyse entwickelt, welche eine unvoreingenommene, robuste und effiziente Untersuchung des Spreadings von Makrophagen erlaubte. Die Kombination dieser Methode mit dem spezifischen siRNA Knockdown ausgewählter Zytoskelett-assoziierter Phosphoproteine führte zur Identifizierung von MYO1e und MYO1f als wichtige Regulatoren dieser Zellfunktion. Darüber hinaus konnte in Makrophagen und DC eine essentielle Rolle für MYO1e im intrazellulären Transport von CCL2 und MHC-II an die Zelloberfläche identifiziert werden, sowie dessen Notwendigkeit für eine vollständige Aktivierung antigen-spezifischer CD4 T Zellen.
KW  - Toll-like-Rezeptoren
KW  - Makrophage
KW  - Phosphoproteine
KW  - Zellskelett
KW  - macrophage
KW  - cytoskeleton
KW  - phosphorylation
KW  - TLR4
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-98843
ER  - 
TY  - JOUR
A1  - Remmele, Christian W.
A1  - Xian, Yibo
A1  - Albrecht, Marco
A1  - Faulstich, Michaela
A1  - Fraunholz, Martin
A1  - Heinrichs, Elisabeth
A1  - Dittrich, Marcus T.
A1  - Müller, Tobias
A1  - Reinhardt, Richard
A1  - Rudel, Thomas
T1  - Transcriptional landscape and essential genes of Neisseria gonorrhoeae
N2  - The WHO has recently classified Neisseria gonorrhoeae as a super-bacterium due to the rapid spread of antibiotic resistant derivatives and an overall dramatic increase in infection incidences. Genome sequencing has identified potential genes, however, little is known about the transcriptional organization and the presence of non-coding RNAs in gonococci. We performed RNA sequencing to define the transcriptome and the transcriptional start sites of all gonococcal genes and operons. Numerous new transcripts including 253 potentially non-coding RNAs transcribed from intergenic regions or antisense to coding genes were identified. Strikingly, strong antisense transcription was detected for the phase-variable opa genes coding for a family of adhesins and invasins in pathogenic Neisseria, that may have regulatory functions. Based on the defined transcriptional start sites, promoter motifs were identified. We further generated and sequenced a high density Tn5 transposon library to predict a core of 827 gonococcal essential genes, 133 of which have no known function. Our combined RNA-Seq and Tn-Seq approach establishes a detailed map of gonococcal genes and defines the first core set of essential gonococcal genes.
KW  - Neisseria gonorrhoeae
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-113676
ER  - 
TY  - JOUR
A1  - Linder, Bastian
A1  - Hirmer, Anja
A1  - Gal, Andreas
A1  - Rüther, Klaus
A1  - Bolz, Hanno Jörn
A1  - Winkler, Christoph
A1  - Laggerbauer, Bernhard
A1  - Fischer, Utz
T1  - Identification of a PRPF4 Loss-of-Function Variant That Abrogates U4/U6.U5 Tri-snRNP Integration and Is Associated with Retinitis Pigmentosa
N2  - Pre-mRNA splicing by the spliceosome is an essential step in the maturation of nearly all human mRNAs. Mutations in six spliceosomal proteins, PRPF3, PRPF4, PRPF6, PRPF8, PRPF31 and SNRNP200, cause retinitis pigmentosa (RP), a disease characterized by progressive photoreceptor degeneration. All splicing factors linked to RP are constituents of the U4/U6.U5 tri-snRNP subunit of the spliceosome, suggesting that the compromised function of this particle may lead to RP. Here, we report the identification of the p.R192H variant of the tri-snRNP factor PRPF4 in a patient with RP. The mutation affects a highly conserved arginine residue that is crucial for PRPF4 function. Introduction of a corresponding mutation into the zebrafish homolog of PRPF4 resulted in a complete loss of function in vivo. A series of biochemical experiments suggested that p.R192H disrupts the binding interface between PRPF4 and its interactor PRPF3. This interferes with the ability of PRPF4 to integrate into the tri-snRNP, as shown in a human cell line and in zebrafish embryos. These data suggest that the p.R192H variant of PRPF4 represents a functional null allele. The resulting haploinsufficiency of PRPF4 compromises the function of the tri-snRNP, reinforcing the notion that this spliceosomal particle is of crucial importance in the physiology of the retina.
KW  - zebrafish
KW  - embryos
KW  - immunoprecipitation
KW  - arginine
KW  - messenger RNA
KW  - spliceosomes
KW  - mutation
KW  - RNA splicing
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-113663
ER  - 
TY  - JOUR
A1  - Vergho, Daniel Claudius
A1  - Kneitz, Susanne
A1  - Kalogirou, Charis
A1  - Burger, Maximilian
A1  - Krebs, Markus
A1  - Rosenwald, Andreas
A1  - Spahn, Martin
A1  - Löser, Andreas
A1  - Kocot, Arkadius
A1  - Riedmiller, Hubertus
A1  - Kneitz, Burkhard
T1  - Impact of miR-21, miR-126 and miR-221 as Prognostic Factors of Clear Cell Renal Cell Carcinoma with Tumor Thrombus of the Inferior Vena Cava
N2  - Clear cell renal cell carcinoma (ccRCC) characterized by a tumor thrombus (TT) extending into the inferior vena cava (IVC) generally indicates poor prognosis. Nevertheless, the risk for tumor recurrence after nephrectomy and thrombectomy varies. An applicable and accurate prediction system to select ccRCC patients with TT of the IVC (ccRCC/TT) at high risk after nephrectomy is urgently needed, but has not been established up to now. To our knowledge, a possible role of microRNAs (miRs) for the development of ccRCC/TT or their impact as prognostic markers in ccRCC/TT has not been explored yet. Therefore, we analyzed the expression of the previously described onco-miRs miR-200c, miR-210, miR-126, miR-221, let-7b, miR-21, miR-143 and miR-141 in a study collective of 74 ccRCC patients. Using the expression profiles of these eight miRs we developed classification systems that accurately differentiate ccRCC from non-cancerous renal tissue and ccRCC/TT from tumors without TT. In the subgroup of 37 ccRCC/TT cases we found that miR-21, miR-126, and miR-221 predicted cancer related death (CRD) accurately and independently from other clinico-pathological features. Furthermore, a combined risk score based on the expression of miR-21, miR-126 and miR-221 was developed and showed high sensitivity and specificity to predict cancer specific survival (CSS) in ccRCC/TT. Using the combined risk score we were able to classify ccRCC/TT patients correctly into high and low risk cases. The risk stratification by the combined risk score (CRS) will benefit from further cohort validation and might have potential for clinical application as a molecular prediction system to identify high- risk ccRCC/TT patients.
KW  - forecasting
KW  - metastasis
KW  - renal cancer
KW  - renal cell carcinoma
KW  - kidneys
KW  - surgical oncology
KW  - surgical and invasive medical procedures
KW  - regression analysis
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-113633
ER  -