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111.
Identification of Stk25 as a genetic modifier of Tau phosphorylation in Dab1-mutant mice 总被引:1,自引:0,他引:1
Matsuki T Zaka M Guerreiro R van der Brug MP Cooper JA Cookson MR Hardy JA Howell BW 《PloS one》2012,7(2):e31152
Hyperphosphorylation of the microtubule binding protein Tau is a feature of a number of neurodegenerative diseases, including Alzheimer's disease. Tau is hyperphosphorylated in the hippocampus of dab1-null mice in a strain-dependent manner; however, it has not been clear if the Tau phosphorylation phenotype is a secondary effect of the morbidity of these mutants. The dab1 gene encodes a docking protein that is required for normal brain lamination and dendritogenesis as part of the Reelin signaling pathway. We show that dab1 gene inactivation after brain development leads to Tau hyperphosphorylation in anatomically normal mice. Genomic regions that regulate the phospho Tau phenotype in dab1 mutants have previously been identified. Using a microarray gene expression comparison between dab1-mutants from the high-phospho Tau expressing and low-phospho Tau expressing strains, we identified Stk25 as a differentially expressed modifier of dab1-mutant phenotypes. Stk25 knockdown reduces Tau phosphorylation in embryonic neurons. Furthermore, Stk25 regulates neuronal polarization and Golgi morphology in an antagonistic manner to Dab1. This work provides insights into the complex regulation of neuronal behavior during brain development and provides insights into the molecular cascades that regulate Tau phosphorylation. 相似文献
112.
Priya Bhutada Sbastien Favre Mariam Jaafar Jutta Hafner Laura Liesinger Stefan Unterweger Karin Bischof Barbara Darnhofer Devanarayanan Siva
Sankar Gerald Rechberger Raghida Abou
Merhi Simon Lebaron Ruth Birner-Gruenberger Dieter Kressler Anthony
K Henras Brigitte Pertschy 《Nucleic acids research》2022,50(17):10053
Eukaryotic ribosome synthesis involves more than 200 assembly factors, which promote ribosomal RNA (rRNA) processing, modification and folding, and assembly of ribosomal proteins. The formation and maturation of the earliest pre-60S particles requires structural remodeling by the Npa1 complex, but is otherwise still poorly understood. Here, we introduce Rbp95 (Ycr016w), a constituent of early pre-60S particles, as a novel ribosome assembly factor. We show that Rbp95 is both genetically and physically linked to most Npa1 complex members and to ribosomal protein Rpl3. We demonstrate that Rbp95 is an RNA-binding protein containing two independent RNA-interacting domains. In vivo, Rbp95 associates with helix H95 in the 3′ region of the 25S rRNA, in close proximity to the binding sites of Npa1 and Rpl3. Additionally, Rbp95 interacts with several snoRNAs. The absence of Rbp95 results in alterations in the protein composition of early pre-60S particles. Moreover, combined mutation of Rbp95 and Npa1 complex members leads to a delay in the maturation of early pre-60S particles. We propose that Rbp95 acts together with the Npa1 complex during early pre-60S maturation, potentially by promoting pre-rRNA folding events within pre-60S particles. 相似文献
113.
114.
ABSTRACT The present work investigates the relationships between nitrogen fixation, carbon metabolism and oxygen consumption by bacteroids of Mesorhizobium ciceri in root nodules of chick-pea plants. Its aim was to establish whether some of the compounds which accumulate under salt stress may be used as respiratory substrates by bacteroids to fuel their own metabolism and nitrogenase activity. Plants were grown in a growth chamber, and salt stress was induced by adding 50 mM NaCl to the nutrient solution at sowing. The data presented here show a rise in fermentative metabolism in nodules of chick-pea plants exposed to high salinity, and suggest that proline, lactate or ethanol, may play an important role as energy-yielding substrates for bacteroids in this plant species. The bacteroids could utilize glucose as a respiratory substrate both under control and saline conditions, while malate did not appear to be the preferred substrate in the presence of salt. 相似文献
115.
116.
Bradley RD; Adkins RM; Honeycutt RL; McDonald JH 《Molecular biology and evolution》1998,15(6):709-717
Using the strictly neutral model as a null hypothesis, we tested for
deviations from expected levels of nucleotide polymorphism at the alcohol
dehydrogenase locus (Adh-1) within and among four species of pocket gophers
(Geomys bursarius major, G. knoxjonesi, G. texensis llanensis, and G.
attwateri). The complete protein-encoding region was examined, and 10
unique alleles, representing both electromorphic and cryptic alleles, were
used to test hypotheses (e.g., the neutral model) concerning the
maintenance of genetic variation. Nineteen variable sites were identified
among the 10 alleles examined, including 9 segregating sites occurring in
synonymous positions and 10 that were nonsynonymous. Several statistical
methods, including those that test for within-species variation as well as
those that examine variation within and among species, failed to reject the
null hypothesis that variation (both within and between species of Geomys)
at the Adh locus is consistent with the neutral theory. However, there was
significant heterogeneity in the ratio of polymorphism to divergence across
the gene, with polymorphisms clustered in the first half of the coding
region and fixed differences clustered in the second half of the gene. Two
alternative hypotheses are discussed as possible explanations for this
heterogeneity: an old balanced polymorphism in the first half of the gene
or a recent selective sweep in the second half of the gene.
相似文献
117.
Venous (maternal) and cord blood (neonatal) samples of Omani women who had a daily supplement of Centrum Materna multivitamin and multimineral tablet throughout pregnancy were investigated at late preterm (n=37) and at term (n=37) delivery for erythrocyte indices, micromineral, antioxidant, and lipid values. Hemoglobin (Hb), hematocrit (HCT), mean cell volume (MCV), red cell distribution width (RDW), copper (Cu), zinc (Zn), ceruloplasmin, erythrocyte Cu-Zn superoxide dismutase (Cu-Zn SOD), cholesterol, apolipoprotein (apo) A-I and apo B were measured by appropriate analytical systems. Cu/zinc and Cu/ceruloplasmin ratios were calculated. The erythrocyte indices were normal in neonatal blood but showed borderline anemia in maternal blood of both groups. There were significantly decreased values of Cu (P=0.012), Zn (P=0.001), apo A-I (P=0.029), and Cu/ceruloplasmin ratio (P=0.032) in late preterm compared to term mothers. Significantly decreased values of Cu (P=0.003), ceruloplasmin (P<0.0001), apo A-I (P=0.024), and Cu/Zn ratio (P=007) were observed in late preterm relative to term neonates. Late preterm mothers were significantly younger (P=0.027) than term mothers. Maternal age correlated positively with apo A-I (r=0.424, P=0.012) and negatively with Cu/Zn ratio (r=-0.353, P=0.040). The findings suggest that with daily dietary Centrum Materna supplementation throughout pregnancy, hematological indices were maintained within normal in mothers and neonates, but the levels of microminerals and micromineral ratios were subnormal in late preterm mothers and their neonates. 相似文献
118.
In vitro regeneration and morphogenesis studies in common bean 总被引:1,自引:0,他引:1
Kingdom Kwapata Robab Sabzikar Mariam B. Sticklen James D. Kelly 《Plant Cell, Tissue and Organ Culture》2010,100(1):97-105
An efficient protocol for high frequency in vitro regeneration of multiple shoots and somatic embryos from the embryonic axis
of common bean (Phaseolus vulgaris) was developed. Ten common bean cultivars representing a wide range of diversity among current commercial market classes
were used for in vitro regeneration evaluation in our study. These cultivars were tested on 63 different media formulations
consisting of combinations of cytokinins, namely benzyladenine (BA) and thidiazuron (TDZ) at concentration levels of 0.0,
1.0, 2.5, 5.0 and 10.0 mg l−1 and auxin, namely naphthalene acetic acid (NAA) and indole-3-acetic acid (IAA) at concentration levels of 0.0, 0.05, 0.1
and 1.0 mg l−1. P. vulgaris cv. Olathe pinto bean performed the best producing over 20 multiple shoots per explant while cv. Condor black bean was the
poorest with nine multiple shoots per explant. The optimum media for regeneration of multiple shoots was 4.4 mg l−1 Murashige and Skoog (MS) containing 2.5 mg l−1 BA and 0.1 mg l−1 IAA supplemented with 30 mg l−1 silver nitrate. Adventitious shoots and somatic embryos were regenerated on 4.4 mg l−1 MS medium containing 1 mg l−1 TDZ and 0.05 mg l−1 NAA supplemented with 30 mg l−1 silver nitrate or activated charcoal. Efficient and effective rooting of plantlets was achieved by dipping the cut end base
of in vitro regenerated shoots in 1.0 mg l−1 indole-3-butyric acid (IBA) solution and culturing on media containing 4.4 mg l−1 MS supplemented by 0.1 mg l−1 IAA, NAA or IBA. 相似文献
119.
Multiple studies demonstrate the influence of the limbic system on the processing of sensory events and attentional guidance.
But the mechanisms involved therein are yet not entirely clear. The close connection of handling incoming sensory information
and memory retrieval, like in the case of habituation towards insignificant stimuli, suggests a crucial impact of the hippocampus
on the direction of attention. In this paper we thus present a neurofunctional forward model of a hippocampal comparator function
based on the theory of theta-regulated attention. Subsequently we integrated this comparator model into a multiscale framework
for the simulation of evoked responses. The results of our simulations were compared to experimental data on electroencephalographic
(EEG) correlates of habituation towards familiar stimuli using time-scale analysis. In consequence we are able to present
additional evidence for limbic influences on the direction of attention driven by stimulus novelty and a systems neuroscience
framework for the statements given in the theta-regulated attention hypothesis. 相似文献
120.
Jennifer M. DeBruyn Lauren T. Nixon Mariam N. Fawaz Amy M. Johnson Mark Radosevich 《Applied and environmental microbiology》2011,77(17):6295-6300
Bacteria belonging to phylum Gemmatimonadetes comprise approximately 2% of soil bacterial communities. However, little is known of their ecology due to a lack of cultured representation. Here we present evidence from biogeographical analyses and seasonal quantification of Gemmatimonadetes in soils, which suggests an adaptation to low soil moisture. 相似文献