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71.
Metabolism of rats running up and down an incline 总被引:6,自引:0,他引:6
Armstrong R. B.; Laughlin M. H.; Rome L.; Taylor C. R. 《Journal of applied physiology》1983,55(2):518-521
72.
73.
A selective acetylation of the prostaglandin-forming fatty acid oxygenase (part of the prostaglandin "synthetase" system) occurs with 100 muM concentrations of aspirin (acetylsalicylic acid). The amount of acetylation, measured by counting the [3H]acetyl-protein formed, was proportional to the amount of active, functional oxygenase in a sample. When samples were aged to allow spontaneous inactivation of the oxygenase, the amount of acetylation was proportional to the remaining measurable activity rather than the initial amount of oxygenase protein in the sample. Diethyl dithiocarbamate inhibited the oxygenase activity, but did not interfere with the subsequent acetylation by aspirin. Indomethacin, on the other hand, appeared to inactivate the oxygenase in a manner that interfered only partially with the action of aspirin as an acetylating reagent. The amount of acetylation appeared to be dependent upon the amount of native, undenatured enzyme. The results suggest that the acetylation may be dependent upon an essential functional group or conformation of groups in the catalytic peptide chain(s) that can be destroyed during spontaneous inactivation of the oxygenase, and altered by indomethacin. 相似文献
74.
哈尔滨西郊赤狐冬季巢区的初步研究 总被引:5,自引:2,他引:3
本文利用雪地跟踪方法对哈尔滨西郊5只赤狐在1985-1986年冬季的巢区做了观察。结果表明,5只狐对巢区内各部分使用的强度是不等的,对巢区中部的某些地块使用强度要高于对外围的使用,并具有明显的方向性。5个巢区的平均活动半径为320±68米至557±82米,面积为1.44-4.O9平方公里,线性指数为1.079至2。5只狐相邻距离约1000米。 相似文献
75.
C Allard V Desgagné J Patenaude M Lacroix L Guillemette MC Battista M Doyon J Ménard JL Ardilouze P Perron L Bouchard MF Hivert 《Epigenetics》2015,10(4):342-351
Leptin is an adipokine that acts in the central nervous system and regulates energy balance. Animal models and human observational studies have suggested that leptin surge in the perinatal period has a critical role in programming long-term risk of obesity. In utero exposure to maternal hyperglycemia has been associated with increased risk of obesity later in life. Epigenetic mechanisms are suspected to be involved in fetal programming of long term metabolic diseases. We investigated whether DNA methylation levels near LEP locus mediate the relation between maternal glycemia and neonatal leptin levels using the 2-step epigenetic Mendelian randomization approach. We used data and samples from up to 485 mother-child dyads from Gen3G, a large prospective population-based cohort. First, we built a genetic risk score to capture maternal glycemia based on 10 known glycemic genetic variants (GRS10) and showed it was an adequate instrumental variable (β = 0.046 mmol/L of maternal fasting glucose per additional risk allele; SE = 0.007; P = 7.8 × 10−11; N = 467). A higher GRS10 was associated with lower methylation levels at cg12083122 located near LEP (β = −0.072 unit per additional risk allele; SE = 0.04; P = 0.05; N = 166). Direction and effect size of association between the instrumental variable GRS10 and methylation at cg12083122 were consistent with the negative association we observed using measured maternal glycemia. Lower DNA methylation levels at cg12083122 were associated with higher cord blood leptin levels (β = −0.17 log of cord blood leptin per unit; SE = 0.07; P = 0.01; N = 170). Our study supports that maternal glycemia is part of causal pathways influencing offspring leptin epigenetic regulation. 相似文献
76.
77.
Vaults and telomerase share a common subunit, TEP1. 总被引:10,自引:0,他引:10
V A Kickhoefer A G Stephen L Harrington M O Robinson L H Rome 《The Journal of biological chemistry》1999,274(46):32712-32717
Vaults are large cytoplasmic ribonucleoprotein complexes of undetermined function. Mammalian vaults have two high molecular mass proteins of 193 and 240 kDa. We have identified a partial cDNA encoding the 240-kDa vault protein and determined it is identical to the mammalian telomerase-associated component, TEP1. TEP1 is the mammalian homolog of the Tetrahymena p80 telomerase protein and has been shown to interact specifically with mammalian telomerase RNA and the catalytic protein subunit hTERT. We show that while TEP1 is a component of the vault particle, vaults have no detectable telomerase activity. Using a yeast three-hybrid assay we demonstrate that several of the human vRNAs interact in a sequence-specific manner with TEP1. The presence of 16 WD40 repeats in the carboxyl terminus of the TEP1 protein is a convenient number for this protein to serve a structural or organizing role in the vault, a particle with eight-fold symmetry. The sharing of the TEP1 protein between vaults and telomerase suggests that TEP1 may play a common role in some aspect of ribonucleoprotein structure, function, or assembly. 相似文献
78.
The p80 homology region of TEP1 is sufficient for its association with the telomerase and vault RNAs, and the vault particle 总被引:1,自引:0,他引:1 下载免费PDF全文
TEP1 is a protein component of two ribonucleoprotein complexes: vaults and telomerase. The vault-associated small RNA, termed vault RNA (VR), is dependent upon TEP1 for its stable association with vaults, while the association of telomerase RNA with the telomerase complex is independent of TEP1. Both of these small RNAs have been shown to interact with amino acids 1–871 of TEP1 in an indirect yeast three-hybrid assay. To understand the determinants of TEP1–RNA binding, we generated a series of TEP1 deletions and show by yeast three-hybrid assay that the entire Tetrahymena p80 homology region of TEP1 is required for its interaction with both telomerase and VRs. This region is also sufficient to target the protein to the vault particle. Electrophoretic mobility shift assays using the recombinant TEP1 RNA-binding domain (TEP1–RBD) demonstrate that it binds RNA directly, and that telomerase and VRs compete for binding. VR binds weakly to TEP1–RBD in vitro, but mutation of VR sequences predicted to disrupt helices near its central loop enhances binding. Antisense oligonucleotide-directed RNase H digestion of endogenous VR indicates that this region is largely single stranded, suggesting that TEP1 may require access to the VR central loop for efficient binding. 相似文献
79.
80.
Jacqueline?R.?BeggsEmail author Eckehard?G.?Brockerhoff Juan?C.?Corley Marc?Kenis Maité?Masciocchi Franck?Muller Quentin?Rome Claire?Villemant 《BioControl》2011,56(4):505-526
Insect species associated with human goods continue to be accidentally introduced into new locations. A small proportion of
these introduced species become invasive, causing a range of impacts in the receiving community. It is therefore important
to evaluate the patterns of which species become invasive and which strategies are most successful in managing them. This
review assesses the distribution, abundance, impact and management of the invasive Vespidae worldwide. We identified 34 vespid
species known to be introduced around the world, but the seven most invasive species are all eusocial. Most introduced Vespidae
only occur in one or two countries, but some areas have become geographic hotspots of invasion: Hawaii (15 species), North
America (eight species), New Zealand (five species), Australia (four species) and South America (four species). Two invasive
species, Vespula vulgaris and V. germanica have become particularly widespread and abundant with a range of impacts on biodiversity and ecosystem function. Other successful
invasive species include several Polistes spp., which affect local biodiversity through direct predation or competition for food or space. Toxic baiting has been the
most successful control strategy against invasive vespids to date, although this has mostly been small scale experimental
management as it has proved difficult to develop commercial control products. Development of shelf-stable lures or baits combined
with suitable toxins or pathogens could overcome some of the commercial impediments. Several attempts at biological control
using parasitoids have not successfully reduced invasive wasp populations, although the biocontrol agent has only established
in one case. The social structure of colonies and their high reproductive efficiency have facilitated invasion by these species,
but it also means management at the population level will be difficult. This emphasises the need to prevent such invasions
from occurring in the first place. 相似文献