41 research outputs found
Phosphorylation of the ErbB3 binding protein Ebp1 by p21-activated kinase 1 in breast cancer cells
The ErbB3 binding protein (Ebp1) is a transcriptional corepressor that inhibits the activity of proliferation-associated genes and the growth of human breast cancer cell lines. Treatment of breast cancer cells with the ErbB3 ligand heregulin (HRG) results in increased phosphorylation of Ebp1 and transcriptional repression. The p21-activated serine/threonine kinase 1 (PAK1), which plays an important role in breast cancer progression and resistance to the anti-oestrogen tamoxifen, is also activated by HRG. We therefore examined the ability of PAK1 to phosphorylate and regulate the function of Ebp1. We found that PAK1 phosphorylated Ebp1 in vitro and mapped the phosphorylation site to threonine 261. Both HRG treatment and expression of a constitutively activated PAK1 in MCF-7 breast cancer cells enhanced threonine phosphorylation of Ebp1. In MCF-7 cells, ectopically expressed Ebp1 bound endogenous PAK1 and this association was enhanced by treatment with HRG. Mutation of the PAK1 phosphorylation site to glutamic acid, mimicking a phosphorylated state, completely abrogated the ability of Ebp1 to repress transcription, inhibit growth of breast cancer cell lines and contribute to tamoxifen sensitivity. These studies demonstrate for the first time that Ebp1 is a substrate of PAK1 and the importance of the PAK1 phosphorylation site for the functional activity of Ebp1 in breast cancer cells
Structural insights into the transcriptional and translational roles of Ebp1.
Accepted versio
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Low energy positron diffraction from Cu(111): Importance of surface loss processes at large angles of incidence
Intensities of positrons specularly diffracted from Cu(111) were measured at the Brandeis positron beam facility and analyzed in the energy range 8eV40{degree}. 30 refs., 5 figs., 1 tab
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Field test of Six-Phase Soil Heating and evaluation of engineering design code
A field test was conducted to evaluate the performance of Six-Phase Soil Heating to enhance the removal of contaminants. The purpose of the test was to determine the scale-up characteristics of the Six-Phase Soil Heating technology and to evaluate a computer process simulator developed for the technology. The test heated a 20-ft diameter cylinder of uncontaminated soil to a 10-ft depth. Six-phase ac power was applied at a rate of 30--35 kW using a power system built from surplus electrical components. The test ran unattended, using a computer-based system to record data, alert staff of any excursions in operating conditions via telephone, and provide automatic shut-off of power depending on the type of excursion. The test data included in situ soil temperatures, voltage profiles, and moisture profiles (using a neutron-probetechnique). After 50 days of heating, soil in the center of the array at the 6-ft depth reached 80{degrees}C. Soil temperatures between the two electrodes at this depth reached approximately 75{degrees}C. Data from this test were compared with those predicted by a computer process simulator. The computer process simulator is a modified version of the TOUGH2 code, a thermal porous media code that can be used to determine the movement of air and moisture in soils. The code was modified to include electrical resistive heating and configured such that an application could be run quickly on a workstation (approximately 5 min for 1 day of field operation). Temperature and soil resistance data predicted from the process simulations matched actual data fairly closely. A series of parametric studies was performed to assess the affect of simulation assumptions on predicted parameters
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Engineering scaleup of electrical soil heating for soil decontamination
The objective of PNL`s efforts in electrically based methods for environmental restoration is to provide new and cost-effective means for removing hazardous organic contaminants from soils, and to detoxify those contaminants after they are removed. Recent work has concentrated on two areas: electrical soil heating to remove volatile and semivolatile compounds from soils, and in situ oxidation via a form of low-temperature plasma to decompose nonvolatile and bound contaminants. This paper covers only the electrical soil heating component, and describes recent efforts to model the heating process to enable equipment and energy requirements to be specified. An initial field test of the heating process suggests that the model presented in this paper is correct, within the range of uncertainty in the spatial variations of soil properties. Because of page limitations, a description of this test and discussion of the test results will be relegated to a subsequent publication
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Field test of Six-Phase Soil Heating and evaluation of engineering design code
A field test was conducted to evaluate the performance of Six-Phase Soil Heating to enhance the removal of contaminants. The purpose of the test was to determine the scale-up characteristics of the Six-Phase Soil Heating technology and to evaluate a computer process simulator developed for the technology. The test heated a 20-ft diameter cylinder of uncontaminated soil to a 10-ft depth. Six-phase ac power was applied at a rate of 30--35 kW using a power system built from surplus electrical components. The test ran unattended, using a computer-based system to record data, alert staff of any excursions in operating conditions via telephone, and provide automatic shut-off of power depending on the type of excursion. The test data included in situ soil temperatures, voltage profiles, and moisture profiles (using a neutron-probetechnique). After 50 days of heating, soil in the center of the array at the 6-ft depth reached 80[degrees]C. Soil temperatures between the two electrodes at this depth reached approximately 75[degrees]C. Data from this test were compared with those predicted by a computer process simulator. The computer process simulator is a modified version of the TOUGH2 code, a thermal porous media code that can be used to determine the movement of air and moisture in soils. The code was modified to include electrical resistive heating and configured such that an application could be run quickly on a workstation (approximately 5 min for 1 day of field operation). Temperature and soil resistance data predicted from the process simulations matched actual data fairly closely. A series of parametric studies was performed to assess the affect of simulation assumptions on predicted parameters
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User instructions for the DESCARTES environmental accumulation code. Hanford Environmental Dose Reconstruction Project
The purpose of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation dose that individuals could have received as a result of emissions since 1944 from the Hanford Site near Richland, Washington. The HEDR Project work is conducted under several technical and administrative tasks, among which is the Environmental Pathways and Dose Estimates task. The staff on this task have developed a suite of computer codes which are used to estimate doses to individuals in the public. This document contains the user instructions for the DESCARTES (Dynamic estimates of concentrations and Accumulated Radionuclides in Terrestrial Environments) suite of codes. In addition to the DESCARTES code, this includes two air data preprocessors, a database postprocessor, and several utility routines that are used to format input data needed for DESCARTES
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A LEED study of the MgO(001) surface structure
LEED beam intensities were measured from the freshly cleaved (in UHV) Mg0(001) surface using beam energy modulation to avoid electrical charging. Dynamic LEED analysis of the data indicates: (1) an interlayer relaxation of (1 {plus minus} 2)% and a rumple of the first layer ions of (5 {plus minus} 2.5)%; (2) a new attenuation model containing no adjustable parameters gives fits to the data that are comparable to those using a constant V{sub i}; (3) a weak dependence of the optimum rumpling on the energy range of the data used. The structure determined in this study is compared to others reported in the literature for this surface, and the effects of lattice vibrations, attenuation length and number of surface layers treated exactly are considered. 26 refs., 4 figs