55 research outputs found
Test of Lorentz and CPT violation with Short Baseline Neutrino Oscillation Excesses
The sidereal time dependence of MiniBooNE electron neutrino and anti-electron
neutrino appearance data are analyzed to search for evidence of Lorentz and CPT
violation. An unbinned Kolmogorov-Smirnov test shows both the electron neutrino
and anti-electron neutrino appearance data are compatible with the null
sidereal variation hypothesis to more than 5%. Using an unbinned likelihood fit
with a Lorentz-violating oscillation model derived from the Standard Model
Extension (SME) to describe any excess events over background, we find that the
electron neutrino appearance data prefer a sidereal time-independent solution,
and the anti-electron neutrino appearance data slightly prefer a sidereal
time-dependent solution. Limits of order 10E-20 GeV are placed on combinations
of SME coefficients. These limits give the best limits on certain SME
coefficients for muon neutrino to electron neutrino and anti-muon neutrino to
anti-electron neutrino oscillations. The fit values and limits of combinations
of SME coefficients are provided.Comment: 14 pages, 3 figures, and 2 tables, submitted to Physics Letters
Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF
The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at the Fermilab Long-Baseline Neutrino Facility (LBNF) is described
Cross-regulation between Egr-1 and APE/Ref-1 during early response to oxidative stress in the human osteoblastic HOBIT cell line: Evidence for an autoregulatory loop
The Early Growth Response protein (Egr-1) is a C2H2\u2013zinc finger-containing transcriptional regulator involved in the control
of cell proliferation and apoptosis. Its DNA-binding activity is redox regulated in vitro through the oxidation\u2013reduction of Cys
residues within its DNA-binding domain. APE/Ref-1 is a DNA-repair enzyme with redox modulating activities on several
transcription factors. In this study, by evaluating the effects of different stimuli, we found a similar timing of activation being
suggestive for a common and co-linear regulation for the two proteins. Indeed, we show that APE/Ref-1 increases the Egr-1
DNA-binding activity in unstimulated osteoblastic HOBIT cells. H2O2 stimulation induces a strong interaction between
Egr-1 and APE/Ref-1 at early times upon activation, as assayed by immunoprecipitation experiments. By using a cell
transfection approach, we demonstrated the functional role of this interaction showing that two specific Egr-1 target genes, the
PTEN phosphatase and the thymidine kinase (TK) genes promoters, are activated by contransfection of APE/Ref-1.
Interestingly, by using a cell transfection approach and Chromatin immunoprecipitation assays, we were able to demonstrate
that Egr-1 stimulates the transcriptional activity of APE/Ref-1 gene promoter by a direct interaction with specific DNAbinding
site on its promoter. Taken together, our data delineate a new molecular mechanism of Egr-1 activation occurring
soon after H2O2 stimulation in osteoblastic cells and suggest a model for a positive loop between APE/Ref-1 and Egr-1 that
could explain the early transcriptional activation of APE/Ref-1 gene expression
Cloning and characterization of hIF2, a human homologue of bacterial translation initiation factor, and its interaction with HIV-1 matrix
The cDNA for a human homologue (hIF2) of bacterial (bIF2) and yeast (yIF2) translation initiation factor two (IF2) has been identified during a screen for proteins which interact with HIV-1 matrix. The hIF2 cDNA encodes a 1220-amino-acid protein with a predicted relative molecular mass of 139 kDa, though endogeneous hIF2 migrates anomalously on SDS/PAGE at 180 kDa. hIF2 has an extended N-terminus compared with its homologues, although its central GTP-binding domain and C-terminus are highly conserved, with 58% sequence identity with yIF2. We have confirmed that hIF2 is required for general translation in human cells by generation of a point mutation in the P-loop of the GTP-binding domain. This mutant protein behaves in a transdominant manner in transient transfections and leads to a significant decrease in the translation of a reporter gene. hIF2 interacts directly with HIV-1 matrix and Gag in vitro, and the protein complex can be immunoprecipitated from human cells. This interaction appears to block hIF2 function, since purified matrix protein inhibits translation in a reticulocyte lysate. hIF2 does not correspond to any of the previously characterized translation initiation factors identified in mammals, but its essential role in translation appears to have been conserved from bacteria to humans
Cloning and characterization of hIF2, a human homologue of bacterial translation initiation factor, and its interaction with HIV-1 matrix
The cDNA for a human homologue (hIF2) of bacterial (bIF2) and yeast (yIF2) translation initiation factor two (IF2) has been identified during a screen for proteins which interact with HIV-1 matrix. The hIF2 cDNA encodes a 1220-amino-acid protein with a predicted relative molecular mass of 139 kDa, though endogeneous hIF2 migrates anomalously on SDS/PAGE at 180 kDa. hIF2 has an extended N-terminus compared with its homologues, although its central GTP-binding domain and C-terminus are highly conserved, with 58% sequence identity with yIF2. We have confirmed that hIF2 is required for general translation in human cells by generation of a point mutation in the P-loop of the GTP-binding domain. This mutant protein behaves in a transdominant manner in transient transfections and leads to a significant decrease in the translation of a reporter gene. hIF2 interacts directly with HIV-1 matrix and Gag in vitro, and the protein complex can be immunoprecipitated from human cells. This interaction appears to block hIF2 function, since purified matrix protein inhibits translation in a reticulocyte lysate. hIF2 does not correspond to any of the previously characterized translation initiation factors identified in mammals, but its essential role in translation appears to have been conserved from bacteria to humans
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