TY - JOUR A1 - Micheel, Burkhard T1 - Stichworte zu Thema Immunologie Y1 - 1999 ER - TY - JOUR A1 - Kummer, Volker T1 - Litterski, B., Pflanzengeographische und ökologische Bewertung der Flechtenflora Mecklenburg-Vorpommerns; Berlin, Cramer, 1999 BT - Pflanzengeographische und ökologische Bewertung der Flechtenflora Mecklenburg-Vorpommerns Y1 - 2000 ER - TY - JOUR A1 - Micheel, Burkhard T1 - Stichworte zu Thema Immunologie Y1 - 2000 ER - TY - JOUR A1 - Bell, Elanor M. A1 - Vincent, Amanda C. J. T1 - Art.: Gasterosteiform Y1 - 2002 ER - TY - JOUR A1 - Meyer, Irene A1 - Kuhnert, Oliver A1 - Gräf, Ralph T1 - Functional analyses of lissencephaly-related proteins in Dictyostelium JF - Seminars in cell & developmental biology N2 - Lissencephaly is a severe brain developmental disease in human infants, which is usually caused by mutations in either of two genes, LIS1 and DCX. These genes encode proteins interacting with both the microtubule and the actin systems. Here, we review the implications of data on Dictyostelium LIS1 for the elucidation of LIS1 function in higher cells and emphasize the role of LIS1 and nuclear envelope proteins in nuclear positioning, which is also important for coordinated cell migration during neocortical development. Furthermore, for the first time we characterize Dictyostelium DCX, the only bona fide orthologue of human DCX outside the animal kingdom. We show that DCX functionally interacts with LIS1 and that both proteins have a cytoskeleton-independent function in chemotactic signaling during development. Dictyostelium LIS1 is also required for proper attachment of the centrosome to the nucleus and, thus, nuclear positioning, where the association of these two organelles has turned out to be crucial. It involves not only dynein and dynein-associated proteins such as LIS1 but also SUN proteins of the nuclear envelope. Analyses of Dictyostelium SUN1 mutants have underscored the importance of these proteins for the linkage of centrosomes and nuclei and for the maintenance of chromatin integrity. Taken together, we show that Dictyostelium amoebae, which provide a well-established model to study the basic aspects of chemotaxis, cell migration and development, are well suited for the investigation of the molecular and cell biological basis of developmental diseases such as lissencephaly. KW - Dictyostelium KW - Lissencephaly KW - LIS1 KW - DCX KW - SUN1 KW - Centrosome Y1 - 2011 U6 - https://doi.org/10.1016/j.semcdb.2010.10.007 SN - 1084-9521 VL - 22 IS - 1 SP - 89 EP - 96 PB - Elsevier CY - London ER - TY - JOUR A1 - Van Donk, Ellen A1 - Ianora, Adrianna A1 - Vos, Matthijs T1 - Induced defences in marine and freshwater phytoplankton a review JF - Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica N2 - Many organisms have developed defences to avoid predation by species at higher trophic levels. The capability of primary producers to defend themselves against herbivores affects their own survival, can modulate the strength of trophic cascades and changes rates of competitive exclusion in aquatic communities. Algal species are highly flexible in their morphology, growth form, biochemical composition and production of toxic and deterrent compounds. Several of these variable traits in phytoplankton have been interpreted as defence mechanisms against grazing. Zooplankton feed with differing success on various phytoplankton species, depending primarily on size, shape, cell wall structure and the production of toxins and deterrents. Chemical cues associated with (i) mechanical damage, (ii) herbivore presence and (iii) grazing are the main factors triggering induced defences in both marine and freshwater phytoplankton, but most studies have failed to disentangle the exact mechanism(s) governing defence induction in any particular species. Induced defences in phytoplankton include changes in morphology (e.g. the formation of spines, colonies and thicker cell walls), biochemistry (such as production of toxins, repellents) and in life history characteristics (formation of cysts, reduced recruitment rate). Our categorization of inducible defences in terms of the responsible induction mechanism provides guidance for future work, as hardly any of the available studies on marine or freshwater plankton have performed all the treatments that are required to pinpoint the actual cue(s) for induction. We discuss the ecology of inducible defences in marine and freshwater phytoplankton with a special focus on the mechanisms of induction, the types of defences, their costs and benefits, and their consequences at the community level. KW - Defenses KW - Algae KW - Review KW - Plankton community KW - Cyanobacteria KW - Toxins Y1 - 2011 U6 - https://doi.org/10.1007/s10750-010-0395-4 SN - 0018-8158 SN - 1573-5117 VL - 668 IS - 1 SP - 3 EP - 19 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Kehr, Jan-Christoph A1 - Picchi, Douglas Gatte A1 - Dittmann-Thünemann, Elke T1 - Natural product biosyntheses in cyanobacteria a treasure trove of unique enzymes JF - Beilstein journal of organic chemistry N2 - Cyanobacteria are prolific producers of natural products. Investigations into the biochemistry responsible for the formation of these compounds have revealed fascinating mechanisms that are not, or only rarely, found in other microorganisms. In this article, we survey the biosynthetic pathways of cyanobacteria isolated from freshwater, marine and terrestrial habitats. We especially emphasize modular nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) pathways and highlight the unique enzyme mechanisms that were elucidated or can be anticipated for the individual products. We further include ribosomal natural products and UV-absorbing pigments from cyanobacteria. Mechanistic insights obtained from the biochemical studies of cyanobacterial pathways can inspire the development of concepts for the design of bioactive compounds by synthetic-biology approaches in the future. KW - cyanobacteria KW - natural products KW - NRPS KW - PKS KW - ribosomal peptides Y1 - 2011 U6 - https://doi.org/10.3762/bjoc.7.191 SN - 1860-5397 VL - 7 IS - 2 SP - 1622 EP - 1635 PB - Beilstein-Institut zur Förderung der Chemischen Wissenschaften CY - Frankfurt, Main ER - TY - JOUR A1 - Leimkühler, Silke A1 - Wuebbens, Margot M. A1 - Rajagopalan, K. V. T1 - The history of the discovery of the molybdenum cofactor and novel aspects of its biosynthesis in bacteria JF - Coordination chemistry reviews N2 - The biosynthesis of the molybdenum cofactor in bacteria is described with a detailed analysis of each individual reaction leading to the formation of stable intermediates during the synthesis of molybdopterin from GTP. As a starting point, the discovery of molybdopterin and the elucidation of its structure through the study of stable degradation products are described. Subsequent to molybdopterin synthesis, the molybdenum atom is added to the molybdopterin dithiolene group to form the molybdenum cofactor. This cofactor is either inserted directly into specific molybdoenzymes or is further modified by the addition of nucleotides to molybdopterin phosphate group or the replacement of ligands at the molybdenum center. KW - Molybdenum cofactor KW - Molybdopterin KW - Precursor Z KW - Molybdopterin guanine dinucleotide cofactor KW - Urothione KW - Dithiolene group Y1 - 2011 U6 - https://doi.org/10.1016/j.ccr.2010.12.003 SN - 0010-8545 VL - 255 IS - 9-10 SP - 1129 EP - 1144 PB - Elsevier CY - Lausanne ER - TY - JOUR A1 - Blenau, Wolfgang A1 - Thamm, Markus T1 - Distribution of serotonin (5-HT) and its receptors in the insect brain with focus on the mushroom bodies lessons from Drosophila melanogaster and Apis mellifera JF - Arthropod structure & development N2 - The biogenic amine serotonin (5-hydroxytryptamine, 5-HT) plays a key role in regulating and modulating various physiological and behavioral processes in both protostomes and deuterostomes. The specific functions of serotonin are mediated by its binding to and subsequent activation of membrane receptors. The vast majority of these receptors belong to the superfamily of G-protein-coupled receptors. We report here the in vivo expression pattern of a recently characterized 5-HT(1) receptor of the honeybee Apis mellifera (Am5-HT(1A)) in the mushroom bodies. In addition, we summarize current knowledge on the distribution of serotonin and serotonin receptor subtypes in the brain and specifically in the mushroom bodies of the fruit fly Drosophila melanogaster and the honeybee. Functional studies in these two species have shown that serotonergic signaling participates in various behaviors including aggression, sleep, circadian rhythms, responses to visual stimuli, and associative learning. The molecular, pharmacological, and functional properties of identified 5-HT receptor subtypes from A. mellifera and D. melanogaster will also be summarized in this review. KW - Apis mellifera KW - G-protein-coupled receptor KW - Drosophila melanogaster KW - Mushroom body KW - Serotonin Y1 - 2011 U6 - https://doi.org/10.1016/j.asd.2011.01.004 SN - 1467-8039 VL - 40 IS - 5 SP - 381 EP - 394 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Zhang, Gong A1 - Ignatova, Zoya T1 - Folding at the birth of the nascent chain: coordinating translation with co-translational folding JF - Current opinion in structural biology : review of all advances ; evaluation of key references ; comprehensive listing of papers N2 - In the living cells, the folding of many proteins is largely believed to begin co-translationally, during their biosynthesis at the ribosomes. In the ribosomal tunnel, the nascent peptide may establish local interactions and stabilize alpha-helical structures. Long-range contacts are more likely outside the ribosomes after release of larger segments of the nascent chain. Examples suggest that domains can attain native-like structure on the ribosome with and without population of folding intermediates. The co-translational folding is limited by the speed of the gradual extrusion of the nascent peptide which imposes conformational restraints on its folding landscape. Recent experimental and in silico modeling studies indicate that translation kinetics fine-tunes co-translational folding by providing a time delay for sequential folding of distinct portions of the nascent chain. Y1 - 2011 U6 - https://doi.org/10.1016/j.sbi.2010.10.008 SN - 0959-440X VL - 21 IS - 1 SP - 25 EP - 31 PB - Elsevier CY - London ER -