753,341 research outputs found
The rna-binding ubiquitin ligase mex3a affects glioblastoma tumorigenesis by inducing ubiquitylation and degradation of rig-i
Glioblastoma multiforme (GB) is the most malignant primary brain tumor in humans, with an overall survival of approximatively 15 months. The molecular heterogeneity of GB, as well as its rapid progression, invasiveness and the occurrence of drug-resistant cancer stem cells, limits the efficacy of the current treatments. In order to develop an innovative therapeutic strategy, it is mandatory to identify and characterize new molecular players responsible for the GB malignant phenotype. In this study, the RNA-binding ubiquitin ligase MEX3A was selected from a gene expression analysis performed on publicly available datasets, to assess its biological and still-unknown activity in GB tumorigenesis. We find that MEX3A is strongly up-regulated in GB specimens, and this correlates with very low protein levels of RIG-I, a tumor suppressor involved in differentiation, apoptosis and innate immune response. We demonstrate that MEX3A binds RIG-I and induces its ubiquitylation and proteasome-dependent degradation. Further, the genetic depletion of MEX3A leads to an increase of RIG-I protein levels and results in the suppression of GB cell growth. Our findings unveil a novel molecular mechanism involved in GB tumorigenesis and suggest MEX3A and RIG-I as promising therapeutic targets in GB
Phases found at grain boundary of YBa2Cu3O7-d 50 nm films on SrTiO3 by enhanced anomalous scattering at O:K, Cu:L2,3 and Ba:M4,5 edges
A new phase is detected within 100micrometers of 24 DEG ab grain boundary
(GB) in YBa2Cu3O7-d 50 nm films on SrTiO3 by enhanced (001) anomalous
scattering. Site identification and temperature dependence is interpreted using
crystallographic weights to distinguish enhanced scattering from total electron
yield and fluorescence spectra. The c-axis, c0 indicates that only ortho-I
phase is present far from GB, both ortho-I and II phases are present near GB.
The phase c0 is constant versus temperature across the transition to
superconductivity.Comment: 3 pages and 5 figur
The Optical Gravitational Lensing Experiment. Catalog of stellar proper motions in the OGLE-II Galactic bulge fields
We present a proper motion (\mu) catalogue of 5,080,236 stars in 49 Optical
Gravitational Lensing Experiment II (OGLE-II) Galactic bulge (GB) fields,
covering a range of -11 deg. <l< 11 deg. and -6 deg. <b<3 deg., the total area
close to 11 square degrees. The proper motion measurements are based on 138 -
555 I-band images taken during four observing seasons: 1997-2000. The catalogue
stars are in the magnitude range 11 < I < 18 mag. In particular, the catalogue
includes Red Clump Giants (RCGs) and Red Giants in the GB, and main sequence
stars in the Galactic disc. The proper motions up to \mu = 500 mas/yr were
measured with the mean accuracy of 0.8-3.5 mas/yr, depending on the brightness
of a star. This catalogue may be useful for studying the kinematic of stars in
the GB and the Galactic disk.Comment: 13 pages, 16 figures, MNRAS in pres
Reduced O diffusion through Be doped Pt electrodes
Using first principles electronic structure calculations we screen nine
elements for their potential to retard oxygen diffusion through
poly-crystalline Pt (p-Pt) films. We determine that O diffuses preferentially
as interstitial along Pt grain boundaries (GBs). The calculated barriers are
compatible with experimental estimates. We find that Be controls O diffusion
through p-Pt. Beryllium segregates to Pt GBs at interstitial (i) and
substitutional (s) sites. i-Be is slightly less mobile than O and it repels O,
thus stuffing the GB. s-Be has a high diffusion barrier and it forms strong
bonds to O, trapping O in the GB. Experiments confirm our theoretical
predictions.Comment: 3 pages, 2 figure
Extinction Map of the Galactic center: OGLE-II Galactic bulge fields
We present the reddening (E(V-I)) and Extinction maps in V-band (A_V) and
I-band (A_I) for 48 Optical Gravitational Lensing Experiment II (OGLE-II)
Galactic bulge (GB) fields, covering a range of , with
the total area close to 11 square degrees. These measurements are based on
two-band photometry of Red Clump Giant (RCG) stars in OGLE-II VI maps of GB. We
confirm the anomalous value of the ratio of total to selective extinction
, depending on the line of sight, as
measured by Udalski (2003). By using the average value of with
the standard deviation sdev=0.085, we measured E(V-I), A_V and A_I, and we
obtained extinction and reddening maps with a high spatial resolution of , depending on the stellar density of each field. We assumed
that average, reddening corrected colours of red clump giants are the same in
every field. The maps cover the range 0.42<E(V-I)<3.5, 0.83<A_V<6.9 and
0.41<A_I<3.4 mag respectively. The zero points of these maps are calibrated by
using V-K colours of 20 RR Lyrae ab variables (RRab) in Baade's window. The
apparent reddening corrected I-band magnitudes of the RCGs change by +0.4 mag
while the Galactic coordinate l varies from to ,
indicating that these stars are in the Galactic Bar. The reddening corrected
colour of RRab and RCGs in GB are consistent with colours of local stars, while
in the past these colours were claimed to be different.Comment: 13 pages, 15 figures, Accepted for publication in MNRA
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