Messina G.,University of Rome La Sapienza |
Damia E.,University of Rome La Sapienza |
Fanti L.,University of Rome La Sapienza |
Atterrato M.T.,University of Rome La Sapienza |
And 13 more authors.
Journal of Cell Science
The evolutionarily conserved family of Bucentaur (BCNT) proteins exhibits a widespread distribution in animal and plants, yet its biological role remains largely unknown. Using Drosophila melanogaster as a model organism, we investigated the in vivo role of the Drosophila BCNT member called YETI. We report that loss of YETI causes lethality before pupation and defects in higherorder chromatin organization, as evidenced by severe impairment in the association of histone H2A.V, nucleosomal histones and epigenetic marks with polytene chromosomes. We also find that YETI binds to polytene chromosomes through its conserved BCNT domain and interacts with the histone variant H2A.V, HP1a and Domino-A (DOM-A), the ATPase subunit of the DOM/Tip60 chromatin remodeling complex. Furthermore, we identify YETI as a downstream target of the Drosophila DOM-A. On the basis of these results, we propose that YETI interacts with H2A.Vexchanging machinery, as a chaperone or as a new subunit of the DOM/Tip60 remodeling complex, and acts to regulate the accumulation of H2A.V at chromatin sites. Overall, our findings suggest an unanticipated role of YETI protein in chromatin organization and provide, for the first time, mechanistic clues on how BCNT proteins control development in multicellular organisms. © 2014. Published by The Company of Biologists Ltd. Source
De Angelis S.,Applicate |
De Angelis S.,UniversitaFederico |
Della Corte V.,Applicate |
Baratta G.A.,National institute for astrophysics |
And 5 more authors.
Raman analyses have been performed on Interplanetary Dust Particles (IDPs) collected in the lower stratosphere by NASA high-flying aircrafts, dust from comet 81P/Wild2 collected by Stardust mission, and three particles collected in the upper stratosphere by the balloon-borne DUSTER instrument. All samples contain amorphous carbon (aC) with different degrees of structural order. Fe oxides were detected in the IDPs, aliphatic chains were found in comet grains, and three particles collected in the upper stratosphere are calcium carbonate (calcite or aragonite). Raman spectroscopy is a valuable tool for the nondestructive analyses of micrometer-scale constituents of complex natural materials. Copyright © Taylor & Francis Group, LLC. Source
Fiore G.,UniversitaFederico |
Fiore G.,National Institute of Nuclear Physics, Italy
Journal of Physics A: Mathematical and Theoretical
We revisit the exact microscopic equations (in differential, and equivalent integral form) ruling a relativistic cold plasma after the plane-wave Ansatz, without customary approximations. We show that in the Eulerian description the motion of a very diluted plasma initially at rest and excited by an arbitrary transverse plane electromagnetic travelling-wave has a very simple and explicit dependence on the transverse electromagnetic potential; for a non-zero density plasma the above motion is a good approximation of the real one as long as the back-reaction of the charges on the electromagnetic field can be neglected, i.e. for a time lapse decreasing with the plasma density, and can be used as initial step in an iterative resolution scheme. As one of many possible applications, we use these results to describe how the ponderomotive force of a very intense and short plane laser pulse hitting normally the surface of a plasma boosts the surface electrons into the ion background. In response to this penetration, the electrons are pulled back by the electric force exerted by the ions and the other displaced electrons and may leave the plasma with high energy in the direction opposite to that of propagation of the pulse 'slingshot effect' (Fiore G et al 2013 arXiv:1309.1400). © 2014 IOP Publishing Ltd. Source
Paduano F.,UniversitaMagna Graecia |
Dattilo V.,UniversitaMagna Graecia |
Narciso D.,UniversitaMagna Graecia |
Bilotta A.,UniversitaMagna Graecia |
And 8 more authors.
Expression of PTPRJ, which is a ubiquitous receptor-type protein tyrosine phosphatase, is significantly reduced in a vast majority of human epithelial cancers and cancer cell lines (i.e. colon, lung, thyroid, mammary and pancreatic tumours). A possible role for microRNAs (miRNAs) in the negative regulation of PTPRJ expression has never been investigated. In this study, we show that overexpression of microRNA-328 (miR-328) decreases PTPRJ expression in HeLa and SKBr3 cells. Further investigations demonstrate that miR-328 acts directly on the 3′UTR of PTPRJ, resulting in reduced mRNA levels. Luciferase assay and site-specific mutagenesis were used to identify a functional miRNA response element in the 3′UTR of PTPRJ. Expression of miR-328 significantly enhances cell proliferation in HeLa and SKBr3 cells, similar to the effects of downregulation of PTPRJ with small interfering RNA. Additionally, in HeLa cells, the proliferative effect of miR-328 was not observed when PTPRJ was silenced with small interfering RNA; conversely, restoration of PTPRJ expression in miR-328-overexpressing cells abolished the proliferative activity of miR-328. In conclusion, we report the identification of miR-328 as an important player in the regulation of PTPRJ expression, and we propose that the interaction of miR-328 with PTPRJ is responsible for miR-328-dependent increase of epithelial cell proliferation. © 2012 The Authors Journal compilation © 2012 FEBS. Source
Verloes A.,University Paris Diderot |
Verloes A.,French Institute of Health and Medical Research |
Di Donato N.,Carl Gustav Carus Institute |
Masliah-Planchon J.,University Paris Diderot |
And 46 more authors.
European Journal of Human Genetics
Baraitser-Winter, Fryns-Aftimos and cerebrofrontofacial syndrome types 1 and 3 have recently been associated with heterozygous gain-of-function mutations in one of the two ubiquitous cytoplasmic actin-encoding genes ACTB and ACTG1 that encode β- and γ-actins. We present detailed phenotypic descriptions and neuroimaging on 36 patients analyzed by our group and six cases from the literature with a molecularly proven actinopathy (9 ACTG1 and 33 ACTB). The major clinical anomalies are striking dysmorphic facial features with hypertelorism, broad nose with large tip and prominent root, congenital non-myopathic ptosis, ridged metopic suture and arched eyebrows. Iris or retinal coloboma is present in many cases, as is sensorineural deafness. Cleft lip and palate, hallux duplex, congenital heart defects and renal tract anomalies are seen in some cases. Microcephaly may develop with time. Nearly all patients with ACTG1 mutations, and around 60% of those with ACTB mutations have some degree of pachygyria with anteroposterior severity gradient, rarely lissencephaly or neuronal heterotopia. Reduction of shoulder girdle muscle bulk and progressive joint stiffness is common. Early muscular involvement, occasionally with congenital arthrogryposis, may be present. Progressive, severe dystonia was seen in one family. Intellectual disability and epilepsy are variable in severity and largely correlate with CNS anomalies. One patient developed acute lymphocytic leukemia, and another a cutaneous lymphoma, indicating that actinopathies may be cancer-predisposing disorders. Considering the multifaceted role of actins in cell physiology, we hypothesize that some clinical manifestations may be partially mutation specific. Baraitser-Winter cerebrofrontofacial syndrome is our suggested designation for this clinical entity. © 2015 Macmillan Publishers Limited All rights reserved. Source