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41.
The mTOR-regulated phosphoproteome reveals a mechanism of mTORC1-mediated inhibition of growth factor signaling 总被引:1,自引:0,他引:1
Hsu PP Kang SA Rameseder J Zhang Y Ottina KA Lim D Peterson TR Choi Y Gray NS Yaffe MB Marto JA Sabatini DM 《Science (New York, N.Y.)》2011,332(6035):1317-1322
The mammalian target of rapamycin (mTOR) protein kinase is a master growth promoter that nucleates two complexes, mTORC1 and mTORC2. Despite the diverse processes controlled by mTOR, few substrates are known. We defined the mTOR-regulated phosphoproteome by quantitative mass spectrometry and characterized the primary sequence motif specificity of mTOR using positional scanning peptide libraries. We found that the phosphorylation response to insulin is largely mTOR dependent and that mTOR exhibits a unique preference for proline, hydrophobic, and aromatic residues at the +1 position. The adaptor protein Grb10 was identified as an mTORC1 substrate that mediates the inhibition of phosphoinositide 3-kinase typical of cells lacking tuberous sclerosis complex 2 (TSC2), a tumor suppressor and negative regulator of mTORC1. Our work clarifies how mTORC1 inhibits growth factor signaling and opens new areas of investigation in mTOR biology. 相似文献
42.
Ernst RK Yi EC Guo L Lim KB Burns JL Hackett M Miller SI 《Science (New York, N.Y.)》1999,286(5444):1561-1565
Cystic fibrosis (CF) patients develop chronic airway infections with Pseudomonas aeruginosa (PA). Pseudomonas aeruginosa synthesized lipopolysaccharide (LPS) with a variety of penta- and hexa-acylated lipid A structures under different environmental conditions. CF patient PA synthesized LPS with specific lipid A structures indicating unique recognition of the CF airway environment. CF-specific lipid A forms containing palmitate and aminoarabinose were associated with resistance to cationic antimicrobial peptides and increased inflammatory responses, indicating that they are likely to be involved in airway disease. 相似文献
43.
44.
Fortunel NO Otu HH Ng HH Chen J Mu X Chevassut T Li X Joseph M Bailey C Hatzfeld JA Hatzfeld A Usta F Vega VB Long PM Libermann TA Lim B 《Science (New York, N.Y.)》2003,302(5644):393; author reply 393
45.
本试验对家蚕茧层练减率进行了遗传及育种学的研究,结果表明,不同化性间、不同系统间,不同品种间以及品种内雌雄性间的茧层练减率均有很显著差异,茧层练减率与全茧量,茧层量,茧层率的相关关系没有一致倾向,按海曼(Hayman)模型估算出茧层练减率的遗传参数为: D=1.8341、H_1=0.2793、H_2=0.2690、F=-0.0798;在茧层练减率的遗传成分中,以加性成分为主,茧层练减率显性效应由一个或一组不完全显性的主效基因控制;茧层练减率的广义遗传力为91.16%狭义遗传力为82.21%。茧层练减率的一般配合力间以及特殊配合力间差异很显著。茧层练减率一般情况下表现为负向杂种优势,通过用系统育种法和杂交育种法对茧层练减率进行选择试验,表明选择有效,但以杂交育种法更为理想。 相似文献
46.
Gelfand MJ Raver JL Nishii L Leslie LM Lun J Lim BC Duan L Almaliach A Ang S Arnadottir J Aycan Z Boehnke K Boski P Cabecinhas R Chan D Chhokar J D'Amato A Ferrer M Fischlmayr IC Fischer R Fülöp M Georgas J Kashima ES Kashima Y Kim K Lempereur A Marquez P Othman R Overlaet B Panagiotopoulou P Peltzer K Perez-Florizno LR Ponomarenko L Realo A Schei V Schmitt M Smith PB Soomro N Szabo E Taveesin N Toyama M Van de Vliert E Vohra N Ward C Yamaguchi S 《Science (New York, N.Y.)》2011,332(6033):1100-1104
With data from 33 nations, we illustrate the differences between cultures that are tight (have many strong norms and a low tolerance of deviant behavior) versus loose (have weak social norms and a high tolerance of deviant behavior). Tightness-looseness is part of a complex, loosely integrated multilevel system that comprises distal ecological and historical threats (e.g., high population density, resource scarcity, a history of territorial conflict, and disease and environmental threats), broad versus narrow socialization in societal institutions (e.g., autocracy, media regulations), the strength of everyday recurring situations, and micro-level psychological affordances (e.g., prevention self-guides, high regulatory strength, need for structure). This research advances knowledge that can foster cross-cultural understanding in a world of increasing global interdependence and has implications for modeling cultural change. 相似文献
47.
María Uriarte Charles B. Yackulic Yili Lim Javier A. Arce-Nazario 《Landscape Ecology》2011,26(8):1151-1164
There is a pressing need to understand the consequences of human activities, such as land transformations, on watershed ecosystem
services. This is a challenging task because different indicators of water quality and yield are expected to vary in their
responsiveness to large versus local-scale heterogeneity in land use and land cover (LUC). Here we rely on water quality data
collected between 1977 and 2000 from dozens of gauge stations in Puerto Rico together with precipitation data and land cover
maps to (1) quantify impacts of spatial heterogeneity in LUC on several water quality indicators; (2) determine the spatial
scale at which this heterogeneity influences water quality; and (3) examine how antecedent precipitation modulates these impacts.
Our models explained 30–58% of observed variance in water quality metrics. Temporal variation in antecedent precipitation
and changes in LUC between measurements periods rather than spatial variation in LUC accounted for the majority of variation
in water quality. Urbanization and pasture development generally degraded water quality while agriculture and secondary forest
re-growth had mixed impacts. The spatial scale over which LUC influenced water quality differed across indicators. Turbidity
and dissolved oxygen (DO) responded to LUC in large-scale watersheds, in-stream nitrogen concentrations to LUC in riparian
buffers of large watersheds, and fecal matter content and in-stream phosphorus concentration to LUC at the sub-watershed scale.
Stream discharge modulated impacts of LUC on water quality for most of the metrics. Our findings highlight the importance
of considering multiple spatial scales for understanding the impacts of human activities on watershed ecosystem services. 相似文献
48.
Shin C Hyun J Lim Y Kim JS Jang YM Kang SJ 《Journal of agricultural and food chemistry》2011,59(21):11579-11584
In this study, a derivative of p-phenoxybenzaldehyde in bamboo shoots was investigated. Bamboo shoots were ground and extracted with water, and an aqueous suspension was purified by SPE using Oasis HLB cartridges. After the SPE procedure, the analytes were analyzed by HPLC with refractive index detection (HPLC-RI). In the HPLC-RI analysis for sucralose, a putative sucralose was detected. In the subsequent HPLC-PDA analysis, the suspicious peak showed a unique UV absorption spectrum with the maximum wavelength at 285 nm indicating the existence of an aromatic ring. The contents of the unknown compound in bamboo shoot products ranged from 0.01 to 0.15 mg/g. The identity of the unknown compound was further confirmed by HPLC-ESI/MS/MS. The molecular weight of the unknown compound was determined to be 244. The chemical structure of the unknown compound was elucidated on the basis of NMR spectroscopic analyses ((1)H, (13)C, DEPT, COSY, HMQC, and HMBC). Finally, the structure of the unknown compound was characterized as 4-(4-dihydroxymethylphenoxy)benzaldehyde. 相似文献
49.
50.
Solubilization of selected free fatty acids in palm oil by biodegradable ethoxylated surfactants 总被引:1,自引:0,他引:1
The solubilization of three major components, viz., palmitic, oleic, and linoleic acids, in palm oil by ethoxylated surfactants was investigated. The results were analyzed in terms of the molecular properties of surfactants and free fatty acids (FFAs). It was found that the solubilities of these FFAs in various micellar solutions depend not only on their octanol-water partition coefficients (Kow), but also on their physicochemical properties. The study on the solubilization kinetics was conducted by choosing palmitic acid as a model solubilizate and Tergitol 15-S-7 as the model surfactant. A first-order film diffusion model, which accounts for the direct uptake of organic molecules at a solid surface into surfactant micelles, was adopted to analyze the effect of surfactant on dissolution of palmitic acid. It was observed that the presence of surfactant reduced the mass-transfer coefficient. Instead, the overall mass-transfer rate was enhanced because of the much higher driving force from the increased solubilization capacity. 相似文献