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161.
Influenza virus assembles in the budozone, a cholesterol-/sphingolipid-enriched (“raft”) domain at the apical plasma membrane, organized by hemagglutinin (HA). The viral protein M2 localizes to the budozone edge for virus particle scission. This was proposed to depend on acylation and cholesterol binding. We show that M2–GFP without these motifs is still transported apically in polarized cells. Employing FRET, we determined that clustering between HA and M2 is reduced upon disruption of HA’s raft-association features (acylation, transmembranous VIL motif), but remains unchanged with M2 lacking acylation and/or cholesterol-binding sites. The motifs are thus irrelevant for M2 targeting in cells. 相似文献
162.
Phase shift of the circannual reproductive rhythm in European hamsters by 2 days of long photoperiod
OBJECTIVEs AND DESIGN: In European hamsters a circannual clock drives the seasonal changes in the reproductive state. Its resetting by photoperiod is clearly phase dependent. In mid subjective winter a 1-month pulse of long photoperiod (LP) advances the onset of the reproductive phase of animals maintained in constant short photoperiod (SP) by up to 1.5 months. The present study investigated whether shorter pulses, i.e. 8, 4 or 2 days LP-pulses are still effective to phase shift the circannual rhythm. MAIN FINDINGS: All pulses induced gonadal development after a similar time relative to the offset of the pulse and earlier than in the control group. Thus, they all shared a similar effectiveness. CONCLUSIONS: In European hamsters a very brief LP-pulse can phase shift the reproductive rhythm but its strength is not determined by its duration at least not in the tested range. 相似文献
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Lake-Ee Quek Stefanie Dietmair Jens O. Krömer Lars K. Nielsen 《Metabolic engineering》2010,12(2):161-171
Mammalian cell culture metabolism is characterized by glucoglutaminolysis, that is, high glucose and glutamine uptake combined with a high rate of lactate and non-essential amino acid secretion. Stress associated with acid neutralization and ammonia accumulation necessitates complex feeding schemes and limits cell densities achieved in fed-batch culture. Conventional and constraint-based metabolic flux analysis has been successfully used to study the metabolic phenotype of mammalian cells in culture, while 13C tracer analysis has been used to study small network models and validate assumptions of metabolism. Large-scale 13C metabolic flux analysis, which is required to improve confidence in the network models and their predictions, remains a major challenge. Advances in both modeling and analytical techniques are bringing this challenge within sight. 相似文献
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Brian C. Shook Stefanie Rassnick Daniel Hall Kenneth C. Rupert Geoffrey R. Heintzelman Kristen Hansen Devraj Chakravarty James L. Bullington Robert H. Scannevin Brian Magliaro Lori Westover Karen Carroll Lisa Lampron Ronald Russell Shawn Branum Kenneth Wells Sandra Damon Scott Youells Xun Li Mel Osbourne Paul F. Jackson 《Bioorganic & medicinal chemistry letters》2010,20(9):2864-2867
A novel series of arylindenopyrimidines were identified as A2A and A1 receptor antagonists. The series was optimized for in vitro activity by substituting the 8- and 9-positions with methylene amine substituents. The compounds show excellent activity in mouse models of Parkinson’s disease when dosed orally. 相似文献
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Liuzzi G Freundlieb N Ridder V Hoppe J Heise K Zimerman M Dobel C Enriquez-Geppert S Gerloff C Zwitserlood P Hummel FC 《Current biology : CB》2010,20(19):1745-1751
Current theoretical positions assume that action-related word meanings are established by functional connections between perisylvian language areas and the motor cortex (MC) according to Hebb's associative learning principle. To test this assumption, we probed the functional relevance of the left MC for learning of a novel action word vocabulary by disturbing neural plasticity in the MC with transcranial direct current stimulation (tDCS). In combination with tDCS, subjects learned a novel vocabulary of 76 concrete, body-related actions by means of an associative learning paradigm. Compared with a control condition with "sham" stimulation, cathodal tDCS reduced success rates in vocabulary acquisition, as shown by tests of novel action word translation into the native language. The analysis of learning behavior revealed a specific effect of cathodal tDCS on the ability to associatively couple actions with novel words. In contrast, we did not find these effects in control experiments, when tDCS was applied to the prefrontal cortex or when subjects learned object-related words. The present study lends direct evidence to the proposition that the left MC is causally involved in the acquisition of novel action-related words. 相似文献
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