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91.
Nucleolar localization of parathyroid hormone-related peptide enhances survival of chondrocytes under conditions that promote apoptotic cell death. 总被引:17,自引:0,他引:17
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J E Henderson N Amizuka H Warshawsky D Biasotto B M Lanske D Goltzman A C Karaplis 《Molecular and cellular biology》1995,15(8):4064-4075
Parathyroid hormone-related peptide (PTHrP) is a mediator of cellular growth and differentiation as well as a cause of malignancy-induced hypercalcemia. Most of the actions of PTHrP have been attributed to its interaction with a specific cell surface receptor that binds the N-terminal domain of the protein. Here we present evidence that PTHrP promotes some of its cellular effects by translocating to the nucleolus. Localization of transiently expressed PTHrP to the nucleolus was dependent on the presence of a highly basic region at the carboxyl terminus of the molecule that bears homology to nucleolar targeting sequences identified within human retroviral (human immunodeficiency virus type 1 and human T-cell leukemia virus type 1) regulatory proteins. Endogenous PTHrP also localized to the nucleolus in osseous cells in vitro and in vivo. Moreover, expression of PTHrP in chondrocytic cells (CFK2) delayed apoptosis induced by serum deprivation, and this effect depended on the presence of an intact nucleolar targeting signal. The present findings demonstrate a unique intracellular mode of PTHrP action and a novel mechanism by which this peptide growth factor may modulate programmed cell death. 相似文献
92.
We have synthesised the -subunit of the chick nicotinic acetylcholine receptor (nAChR) in stable, continuous insect (Spodoptera frugiperda) cell lines. A cDNA was integrated randomly into the insect cell genome under control of a baculovius immediate early gene promoter. Transformed cells were obtained by co-transfection of the insect cells with pIEK1.nAChR, encoding the -subunit cDNA, and pIEK1.neo, encoding the neomycin resistance gene. G-418-resistant clones were selected and expanded into continuous cell lines synthesising the chick nAChR -subunit. Using fluorescence microscopy and ligand binding studies we were able to demonstrate efficient membrane targeting of the receptor subunit in the insect cell plasma membrane. Stable insect cell lines may thus have significant advantages over transient baculovirus vectors for the synthesis and characterisation of heterologous receptor proteins.Abbreviations AcNPV
Autographa californica nuclear polyhedrosis virus
- BTX
-bungarotoxin
- BSA
bovine serum albumin
- FITC
Fluoroscein isothiocyanate
- G418
geneticin-418
- hpi
hours post-infection
-
ie-1
immediate early 1 gene
- nAChR
nicotinic acetylcholine receptor alpha subunit
- Sf
Spodoptera frugiperda
- tPA
tissue plasminogen activator 相似文献
93.
Lipid A-associated proteins from periodontopathogenic bacteria induce interleukin-6 production by human gingival fibroblasts and monocytes 总被引:4,自引:0,他引:4
K. Reddi S. Poole S. Nair S. Meghji B. Henderson M. Wilson 《FEMS immunology and medical microbiology》1995,11(2):137-144
Abstract The aim of this study was to determine whether lipid A-associated proteins (LAP) from two periodontopathogenic species of bacteria were able to stimulate interleukin-6 (IL-6) release from human gingival fibroblasts and myelomonocytic cells. LAP and lipopolysaccharide (LPS) were extracted from Porphyromonas gingivalis and Prevotella intermedia and added to cultures of human gingival fibroblasts and mono-mac-6 monocytic cells. Release of IL-6 into the culture supermatants was determined by ELISA. LAP and LPS from Por. gingivalis , but not from Prev. intermedia , stimulated IL-6 release from both cell types in a dose-dependent manner although LPS was less potent than LAP in inducing IL-6 release from the fibroblasts. IL-6 was detectable in cultures of both cell types following stimulation with LAP from Por. gingivalis at a concentration as low as 10 ng/ml. In response to LAP from Prev. intermedia , IL-6 was produced by mono-mac-6 cells but not by fibroblasts. Our results show that bacterial cell wall components other than LPS can induce IL-6 release from cells of the periodontium in vitro. The production of such potent immunomodulatory agents in vivo may contribute to the connective tissue breakdown characteristic of chronic periodontitis. 相似文献
94.
J. P. Monson R. M. Henderson J. A. Smith R. A. Iles M. Faus-Dader N. D. Carter R. Heath H. Metcalfe R. D. Cohen 《Bioscience reports》1984,4(10):819-825
In perfused rat liver a decrease of cytosol pH, determined with pH-sensitive microelectrodes7 from 7.2 to 6.85 is associated with a 50% fall in ureogenesis from ammonium chloride. In isolated rat hepatocytes the fall in ureogenesis due to acidosis is associated with decrease in the mitochondrial and cytosolic concentration of citrulline. Limitation of carbamoyl phosphate synthesis and thus citrulline supply could be responsible for the inhibition of ureogenesis observed. 相似文献
95.
Acetylation of rat testis histones H2B and TH2B 总被引:3,自引:1,他引:2
The in vivo acetylation of rat testis histones H3 and H4 has been demonstrated in previous studies. In this study, analysis of purified histone fractions revealed the in vivo acetylation of histone H2B, the testis histone variant designated TH2B, and two or more of the histone H2A variants. These findings are quite significant, because it is possible that all of the core histones are acetylated in elongating spermatids at the time of removal of the entire histone complement for replacement by basic spermatidal transition proteins (S.R. Grimes and N. Henderson, 1983, Arch. Biochem. Biophys. 221, 108-116). 相似文献
96.
97.
Identification, physical map location and sequence of the denV gene from bacteriophage T4 总被引:19,自引:5,他引:14
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The denV gene from bacteriophage T4, which codes for endonuclease V, a small DNA repair enzyme, has been cloned and identified by an approach combining DNA sequencing and genetics, independent of the phenotypic effect of the cloned gene. Appropriate DenV+ and DenV- deletion mutants were mapped physically to define precisely a region encompassing the denV gene. This region was sequenced in order to identify a protein-coding sequence of the correct size for the denV gene (400-500 bp). Finally, identification was confirmed by sequencing the corresponding fragments cloned from four genetically and phenotypically well-characterized denV mutants. The denV gene is located at 64 kb on the T4 genome, adjacent to the ipII gene, and codes for a basic protein of 138 amino acids with a deduced molecular weight of 16,078. 相似文献
98.
This paper describes the experience of the College of Physicians and Surgeons of Ontario in developing and conducting a program for the peer assessment of physicians'' office practices that would allow the standards of medical practice to be reviewed and assessed. Following two pilot projects in 1978 and 1979 that demonstrated the need, the feasibility and the acceptance of a peer assessment program the office practices of 391 randomly selected physicians were reviewed in 1981 and 1982. Included in the sample were 255 general/family practitioners and 136 specialists in seven fields. Serious deficiencies were found in the medical records of or in the care provided by 30 of the general/family practitioners and 3 of the specialists, accounting for 8% of the practices studied. The difference between the two groups of physicians was statistically significant (p less than 0.01). No predictors of significance were demonstrated in the general/family practitioner group. When follow-up assessments were done most of the physicians were found to have made the improvements that had been recommended. 相似文献
99.
J Henderson 《BMJ (Clinical research ed.)》1984,288(6435):1967-1968
An age-sex register for use in general practice was obtained directly from the family practitioner committee computer by direct transfer of data to a microcomputer. 相似文献
100.
D. W. Johnson G. S. Henderson D. D. Huff S. E. Lindberg D. D. Richter D. S. Shriner D. E. Todd J. Turner 《Oecologia》1982,54(2):141-148
Summary Sulfur (S) cycling in a chestnut oak forest on Walker Branch Watershed, Tennessee, was dominated by geochemical processes involving sulfate. Even though available SO
4
2-
was present far in excess of forest nutritional requirements, the ecosystem as a whole accumulated 60% of incoming SO4–S. Most (90%) of this accumulation occurred by SO
4
2-
adsorption in sesquioxide-rich subsurface soils, with a relatively minor amount accumulating and cycling as SO
4
2-
within vegetative components. Organic sulfates are thought to constitute a large proportion of total S in surface soils, also, and to provide a pool of readily mineralized available S within the ecosystem.Research sponsored by Division of Biomedical and Environmental Research, U.S. Department of Energy, under contract W-7405-eng-26 with Union Carbide Corporation. Soil ester sulfate work sponsored by contract RP-1813-1 with the Electric Power Research Institute. Publication No. 1990, Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 相似文献