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941.
Hee Jin Park Hyeong Cheol Park Sang Yeol Lee Hans J. Bohnert Dae-Jin Yun 《Journal of Plant Biology》2011,54(5):275-285
Posttranslational modifications of proteins by small polypeptides including ubiquitination, neddylation (related to ubiquitin
(RUB) conjugation), and sumoylation are implicated in plant growth and development, and they regulate protein degradation,
location, and interaction with other proteins. Ubiquitination mediates the selective degradation of proteins by the ubiquitin
(Ub)/proteasome pathway. The ubiquitin-like protein RUB is conjugated to cullins, which are part of a ubiquitin E3 ligase
complex that is involved in auxin hormonal signaling. Sumoylation, by contrast, is known for its involvement in guiding protein
interactions related to abiotic and biotic stresses and in the regulation of flowering time. ATG8/ATG12-mediated autophagy
influences degradation and recycling of cellular components. Other ubiquitin-like modifiers (ULPs) such as homology to Ub-1,
ubiquitin-fold modifier 1, and membrane-anchored Ub-fold are also found in Arabidopsis. ULPs share similar three-dimensional structures and a conjugation system, including E1 activating enzymes, E2 conjugation
enzymes, and E3 ligases, as well as proteases for deconjugation and recycling of the tags. However, each of the ULP posttranslational
modifications possesses its own specific enzymes and modifies its specific targets selectively. This review discusses recent
findings on ubiquitination and ubiquitin-like modifier processes and their roles in the posttranslational modification of
proteins in Arabidopsis. 相似文献
942.
Dawei Jiang Yunchao Liu Aiping Wang Gaiping Zhang Guoyu Yang Yumei Chen Pengchao Ji Chang Liu Yapeng Song Yunfang Su Guoqiang Wang Jucai Wang Baolei Zhao Ruiguang Deng 《Biotechnology letters》2016,38(6):901-908
Objectives
To improve the expression of soluble IBDV VP2 protein by using different tagged vectors in Escherichia coli.Results
Fusion tags, Grifin, MBP, SUMO, thioredoxin, γ-crystallin, ArsC and PpiB, enhanced the expression and solubility of VP2 protein. The fusion proteins were purified by Ni–NTA chromatography, MBP-VP2 showed the highest purity about 90 %. After removing the MBP tag, VP2 self-assembled into virus-like particles, ~25 nm diam. Results from AGP suggested the recombinant IBDV VP2 protein identified by reference serum like IBDV.Conclusion
All the seven tags enhanced the expression and solubility of IBDV VP2 protein. The recombinant protein self-assembly into virus like particles and possess antigenicity as reference IBDV.943.
Venugopal Thayanithy Patrick O’Hare Phillip Wong Xianda Zhao Clifford J. Steer Subbaya Subramanian Emil Lou 《Cell communication and signaling : CCS》2017,15(1):46
Background
Tunneling nanotubes (TNTs) are naturally-occurring filamentous actin-based membranous extensions that form across a wide spectrum of mammalian cell types to facilitate long-range intercellular communication. Valid assays are needed to accurately assess the downstream effects of TNT-mediated transfer of cellular signals in vitro. We recently reported a modified transwell assay system designed to test the effects of intercellular transfer of a therapeutic oncolytic virus, and viral-activated drugs, between cells via TNTs. The objective of the current study was to demonstrate validation of this in vitro approach as a new method for effectively excluding diffusible forms of long- and close-range intercellular transfer of intracytoplasmic cargo, including exosomes/microvesicles and gap junctions in order to isolate TNT-selective cell communication.Methods
We designed several steps to effectively reduce or eliminate diffusion and long-range transfer via these extracellular vesicles, and used Nanoparticle Tracking Analysis to quantify exosomes following implementation of these steps.Results
The experimental approach outlined here effectively reduced exosome trafficking by >95%; further use of heparin to block exosome uptake by putative recipient cells further impeded transfer of these extracellular vesicles.Conclusions
This validated assay incorporates several steps that can be taken to quantifiably control for extracellular vesicles in order to perform studies focused on TNT-selective communication.944.
Dibendu Betal Ramesh Babu Veysi Mehmet 《International Seminars in Surgical Oncology : ISSO》2009,6(1):9
Synovial sarcomas are a rare form of soft tissue sarcomas. We present a case of a 62 year-old male presenting with a left thyroid lump initially though to be a thyroid adenoma but subsequently diagnosed as a monophasic synovial sarcoma of the pharynx. We discuss the diagnosis and treatment of this case. 相似文献
945.
A. Senthil Kumar V. Venkatesalu K. Kannathasan M. Chandrasekaran 《Indian journal of microbiology》2010,50(1):70-75
Bioleaching of uranium was carried out with Turamdih ore sample procured from Uranium Corporation of India Limited, Jaduguda.
The bacterial strain that was used in the leaching experiments was isolated from the Jaduguda mine water sample. Efficiency
of bioleaching was studied by varying parameters like pulp density and initial ferrous concentration as source of energy.
It is observed that the efficiency of bioleaching was 49% at 10% pulp density (w/v) and initial pH 2.0. Addition of external
has no effect on efficiency of bioleaching showing domination of direct leaching mechanism over indirect. 相似文献
946.
Fengjie Cui Zhiqiang Liu Yin Li Lifeng Ping Liying Ping Zhicai Zhang Lin Lin Ying Dong Daming Huang 《Biotechnology and Bioprocess Engineering》2010,15(2):299-307
The Doehlert experimental design was used to optimize the production of mycelial biomass and exopolymer from Hericium erinaceus CZ-2 in this study. Statistical analysis showed that the linear and quadric terms of 3 variables: corn flour, yeast extract,
and corn steep liquor had significant effects. The optimized combination of these 3 variables was confirmed through validation
experiments. The optimal conditions for higher production of mycelial biomass (19.92 g/L) were estimated when the media composition
concentrations were set as: 30.85 g/L, corn flour; 2.81 g/L, yeast extract; 16.9 mL/L, corn steep liquor; 10 g/L, glucose;
1 g/L, KH2PO4; and 0.5 g/L, MgSO4·7H2O; while a maximal exo-polymer yield (1.653 g/L) could be achieved when setting concentrations of: 32.71 g/L, corn flour;
2.35 g/L, Yeast extract; 14.42 mL/L, Corn steep liquor; 10 g/L, glucose; 1 g/L, KH2PO4; and 0.5 g/L, MgSO4·7H2O. The upscale production was also investigated using a 15 L fermentor using the optimized medium. 相似文献
947.
The replicative lifespan of normal somatic cells is restricted by the erosion of telomeres, which are protective caps at the
ends of linear chromosomes. The loss of telomeres induces antiproliferative signals that eventually lead to cellular senescence.
The enzyme complex telomerase can maintain telomeres, but its expression is confined to highly proliferative cells such as
stem cells and tumor cells. The immense regenerative capacity of the hematopoietic system is provided by a distinct type of
adult stem cell: hematopoietic stem cells (HSCs). Although blood cells have to be produced continuously throughout life, the
HSC pool seems not to be spared by aging processes. Indeed, limited expression of telomerase is not sufficient to prevent
telomere shortening in these cells, which is thought ultimately to limit their proliferative capacity. In this review, we
discuss the relevance of telomere maintenance for the hematopoietic stem cell compartment and consider potential functions
of telomerase in this context. We also present possible clinical applications of telomere manipulation in HSCs and new insights
affecting the aging of the hematopoietic stem cell pool and replicative exhaustion.
This work was supported by European Community Grant LSHC-CT-2004-502943 (MOL CANCER MED). 相似文献
948.
949.
Chi Zhang Hanqin Tian Shufen Pan Mingliang Liu Graeme Lockaby Erik B. Schilling John Stanturf 《Ecosystems》2008,11(8):1211-1222
Forest regrowth after cropland abandonment and urban sprawl are two counteracting processes that have influenced carbon (C)
sequestration in the southeastern United States in recent decades. In this study, we examined patterns of land-use/land-cover
change and their effect on ecosystem C storage in three west Georgia counties (Muscogee, Harris, and Meriwether) that form
a rural–urban gradient. Using time series Landsat imagery data including MSS for 1974, TM for 1983 and 1991, and ETM for 2002,
we estimate that from 1974 to 2002, urban land use in the area has increased more than 380% (that is, 184 km2). Most newly urbanized land (63%) has been converted from forestland. Conversely, cropland and pasture area has decreased
by over 59% (that is, 380 km2). Most of the cropland area was converted to forest. As a result, the net change in forest area was small over the past 29
years. Based on Landsat imagery and agricultural census records, we reconstructed an annual gridded data set of land-cover
change for the three counties for the period 1850 to 2002. These data sets were then used as input to the Terrestrial Ecosystem
Model (TEM) to simulate land-use effects on C fluxes and storage for the study area. Simulated results suggest that C uptake
by forest regrowth (approximately 23.0 g C m−2 y−1) was slightly greater than the amount of C released due to deforestation (approximately 18.4 g C m−2 y−1), thus making the three counties a weak C sink. However, the relative importance of different deforestation processes in
this area changed significantly through time. Although agricultural deforestation was generally the most important C-release
process, the amount of C release attributable to urbanization has increased over time. Since 1990, urbanization has accounted
for 29% of total C loss from the study area. We conclude that balancing urban development and forest protection is critically
important for C management and policy making in the southeastern United States. 相似文献
950.
Mohd Zeeshan Ansari Jyoti Sharma Rajesh S Gokhale Debasisa Mohanty 《BMC bioinformatics》2008,9(1):454