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991.
Ute Hehr Daniel E. Pineda-Alvarez Goekhan Uyanik Ping Hu Nan Zhou Andreas Hehr Chayim Schell-Apacik Carola Altus Cornelia Daumer-Haas Annechristin Meiner Peter Steuernagel Erich Roessler Juergen Winkler Maximilian Muenke 《Human genetics》2010,127(5):555-561
Schizencephaly (SCH) is a clinically and etiologically heterogeneous cerebral malformation presenting as unilateral or bilateral hemispheric cleft with direct connection between the inner and outer liquor spaces. The SCH cleft is usually lined by gray matter, which appears polymicrogyric implying an associated impairment of neuronal migration. The majority of SCH patients are sporadic, but familial SCH has been described. An initial report of heterozygous mutations in the homeobox gene EMX2 could not be confirmed in 52 patients investigated in this study in agreement with two independent SCH patient cohorts published previously. SCH frequently occurs with additional cerebral malformations like hypoplasia or aplasia of the septum pellucidum or optic nerve, suggesting the involvement of genes important for the establishment of midline forebrain structures. We therefore considered holoprosencephaly (HPE)-associated genes as potential SCH candidates and report for the first time heterozygous mutations in SIX3 and SHH in a total of three unrelated patients and one fetus with SCH; one of them without obvious associated malformations of midline forebrain structures. Three of these mutations have previously been reported in independent patients with HPE. SIX3 acts directly upstream of SHH, and the SHH pathway is a key regulator of ventral forebrain patterning. Our data indicate that in a subset of patients SCH may develop as one aspect of a more complex malformation of the ventral forebrain, directly result from mutations in the SHH pathway and hence be considered as yet another feature of the broad phenotypic spectrum of holoprosencephaly. 相似文献
992.
Veena Prabhakar Tanja L?ttgert Stefan Geimer Peter D?rmann Stephan Krüger Vinod Vijayakumar Lukas Schreiber Cornelia G?bel Kirstin Feussner Ivo Feussner Kay Marin Pia Staehr Kirsten Bell Ulf-Ingo Flügge Rainer E. H?usler 《The Plant cell》2010,22(8):2594-2617
Restriction of phosphoenolpyruvate (PEP) supply to plastids causes lethality of female and male gametophytes in Arabidopsis thaliana defective in both a phosphoenolpyruvate/phosphate translocator (PPT) of the inner envelope membrane and the plastid-localized enolase (ENO1) involved in glycolytic PEP provision. Homozygous double mutants of cue1 (defective in PPT1) and eno1 could not be obtained, and homozygous cue1 heterozygous eno1 mutants [cue1/eno1(+/−)] exhibited retarded vegetative growth, disturbed flower development, and up to 80% seed abortion. The phenotypes of diminished oil in seeds, reduced flavonoids and aromatic amino acids in flowers, compromised lignin biosynthesis in stems, and aberrant exine formation in pollen indicate that cue1/eno1(+/−) disrupts multiple pathways. While diminished fatty acid biosynthesis from PEP via plastidial pyruvate kinase appears to affect seed abortion, a restriction in the shikimate pathway affects formation of sporopollonin in the tapetum and lignin in the stem. Vegetative parts of cue1/eno1(+/−) contained increased free amino acids and jasmonic acid but had normal wax biosynthesis. ENO1 overexpression in cue1 rescued the leaf and root phenotypes, restored photosynthetic capacity, and improved seed yield and oil contents. In chloroplasts, ENO1 might be the only enzyme missing for a complete plastidic glycolysis. 相似文献
993.
994.
995.
Nicole Adam Cornelia Kriete Dieter Garbe-Schönberg Giorgio Gonnella Stefan Krause Axel Schippers 《Geomicrobiology journal》2020,37(3):242-254
AbstractMicrobial metabolisms in sediments play a pivotal role in marine element cycling. In hydrothermal sediments chemosynthetic microorganisms likely prevail, while in non-hydrothermally impacted sediment regimes microorganisms associated with organic matter decomposition are primarily recognized. To test how these microorganisms are distributed along the hitherto neglected transition zone influenced to different degrees by hydrothermal input we sampled four sediment sites: these were (i) near an active vent, (ii) the outer rim, and (iii) the inactive area of the Kairei hydrothermal field as well as (iv) sediments roughly 200?km south-east of the Kairei field. Chemistry and microbial community compositions were different at all sampling sites. Against expectations, the sediments near the active vent did not host typical chemosynthetic microorganisms and chemistry did not indicate current, extensive hydrothermal venting. Data from the outer rim area of the active Kairei field suggested microbially mediated saponite production and diffuse hydrothermal flow from below accompanied by increased metal concentrations. A steep redox gradient in the inactive Kairei field points towards significant redox driven processes resulting in dissolution of hydrothermal precipitates and intense metal mobilization. Local microorganisms were primarily Chloroflexi, Bacillales, Thermoplasmata, and Thaumarchaeota. 相似文献
996.
Cornelia Speth Martin F. Brodde Magdalena Hagleitner Günter Rambach Hugo Van Aken Manfred Dierich Beate E. Kehrel 《PloS one》2013,8(6)
As a consequence of innate immune activation granulocytes and macrophages produce hypochlorite/hypochlorous acid (HOCl) via secretion of myeloperoxidase (MPO) to the outside of the cells, where HOCl immediately reacts with proteins. Most proteins that become altered by this system do not belong to the invading microorganism but to the host. While there is no doubt that the myeloperoxidase system is capable of directly inactivating HIV-1, we hypothesized that it may have an additional indirect mode of action. We show in this article that HOCl is able to chemically alter proteins and thus turn them into Idea-Ps (Idea-P = immune defence-altered protein), potent amyloid-like and SH-groups capturing antiviral weapons against HIV-1. HOCl-altered plasma proteins (Idea-PP) have the capacity to bind efficiently and with high affinity to the HIV-1 envelope protein gp120, and to its receptor CD4 as well as to the protein disulfide isomerase (PDI). Idea-PP was able to inhibit viral infection and replication in a cell culture system as shown by reduced number of infected cells and of syncytia, resulting in reduction of viral capsid protein p24 in the culture supernatant. The unmodified plasma protein fraction had no effect. HOCl-altered isolated proteins antithrombin III and human serum albumin, taken as representative examples of the whole pool of plasma proteins, were both able to exert the same activity of binding to gp120 and inhibition of viral proliferation. These data offer an opportunity to improve the understanding of the intricacies of host-pathogen interactions and allow the generation of the following hypothetical scheme: natural immune defense mechanisms generate by posttranslational modification of plasma proteins a potent virucidal weapon that immobilizes the virus as well as inhibits viral fusion and thus entry into the host cells. Furthermore simulation of this mechanism in vitro might provide an interesting new therapeutic approach against microorganisms. 相似文献
997.
Christian Jessen Cornelia Roder Javier Felipe Villa Lizcano Christian R. Voolstra Christian Wild 《PloS one》2013,8(6)
Overfishing and land-derived eutrophication are major local threats to coral reefs and may affect benthic communities, moving them from coral dominated reefs to algal dominated ones. The Central Red Sea is a highly under-investigated area, where healthy coral reefs are contending against intense coastal development. This in-situ study investigated both the independent and combined effects of manipulated inorganic nutrient enrichment (simulation of eutrophication) and herbivore exclosure (simulation of overfishing) on benthic algae development. Light-exposed and shaded terracotta tiles were positioned at an offshore patch reef close to Thuwal, Saudi Arabia and sampled over a period of 4 months. Findings revealed that nutrient enrichment alone affected neither algal dry mass nor algae-derived C or N production. In contrast, herbivore exclusion significantly increased algal dry mass up to 300-fold, and in conjunction with nutrient enrichment, this total increased to 500-fold. Though the increase in dry mass led to a 7 and 8-fold increase in organic C and N content, respectively, the algal C/N ratio (18±1) was significantly lowered in the combined treatment relative to controls (26±2). Furthermore, exclusion of herbivores significantly increased the relative abundance of filamentous algae on the light-exposed tiles and reduced crustose coralline algae and non-coralline red crusts on the shaded tiles. The combination of the herbivore exclusion and nutrient enrichment treatments pronounced these effects. The results of our study suggest that herbivore reduction, particularly when coupled with nutrient enrichment, favors non-calcifying, filamentous algae growth with high biomass production, which thoroughly outcompetes the encrusting (calcifying) algae that dominates in undisturbed conditions. These results suggest that the healthy reefs of the Central Red Sea may experience rapid shifts in benthic community composition with ensuing effects for biogeochemical cycles if anthropogenic impacts, particularly overfishing, are not controlled. 相似文献
998.
Anna Biason-Lauber Marianne Böni-Schnetzler Basil P. Hubbard Karim Bouzakri Andrea Brunner Claudia Cavelti-Weder Cornelia Keller Monika Meyer-Böni Daniel T. Meier Caroline Brorsson Katharina Timper Gil Leibowitz Andrea Patrignani Remy Bruggmann Gino Boily Henryk Zulewski Andreas Geier Jennifer M. Cermak Marc Y. Donath 《Cell metabolism》2013,17(3):448-455
999.
Xiaoli Du Caroline Barisch Peggy Paschke Cornelia Herrfurth Oliver Bertinetti Nadine Pawolleck Heike Otto Harald Rühling Ivo Feussner Friedrich W. Herberg Markus Maniak 《Eukaryotic cell》2013,12(11):1517-1529
Across all kingdoms of life, cells store energy in a specialized organelle, the lipid droplet. In general, it consists of a hydrophobic core of triglycerides and steryl esters surrounded by only one leaflet derived from the endoplasmic reticulum membrane to which a specific set of proteins is bound. We have chosen the unicellular organism Dictyostelium discoideum to establish kinetics of lipid droplet formation and degradation and to further identify the lipid constituents and proteins of lipid droplets. Here, we show that the lipid composition is similar to what is found in mammalian lipid droplets. In addition, phospholipids preferentially consist of mainly saturated fatty acids, whereas neutral lipids are enriched in unsaturated fatty acids. Among the novel protein components are LdpA, a protein specific to Dictyostelium, and Net4, which has strong homologies to mammalian DUF829/Tmem53/NET4 that was previously only known as a constituent of the mammalian nuclear envelope. The proteins analyzed so far appear to move from the endoplasmic reticulum to the lipid droplets, supporting the concept that lipid droplets are formed on this membrane. 相似文献
1000.
Ines Kovacikova Silvia Polakova Zsigmond Benko Lubos Cipak Lijuan Zhang Cornelia Rumpf Eva Miadokova Juraj Gregan 《Cell cycle (Georgetown, Tex.)》2013,12(4):618-624
The reduction of chromosome number during meiosis is achieved by two successive rounds of chromosome segregation after just single round of DNA replication. To identify novel proteins required for the proper segregation of chromosomes during meiosis, we analyzed the consequences of deleting Schizosaccharomyces pombe genes predicted to encode protein kinases that are not essential for cell viability. We show that Mph1, a member of the Mps1 family of spindle assembly checkpoint kinases, is required to prevent meiosis I homolog non-disjunction. We also provide evidence for a novel function of Spo4, the fission yeast ortholog of Dbf4-dependent Cdc7 kinase, in regulating the length of anaphase II spindles. In the absence of Spo4, abnormally elongated anaphase II spindles frequently overlap and thus destroy the linear order of nuclei in the ascus. Our observation that the spo4Δ mutant phenotype can be partially suppressed by inhibiting Cdc2-as suggests that dysregulation of the activity of this cyclin-dependent kinase may cause abnormal elongation of anaphase II spindles in spo4Δ mutant cells. 相似文献