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1.
Nature ; 627(8005): 759-762, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38538936

RESUMO

The early evolution of a supernova (SN) can reveal information about the environment and the progenitor star. When a star explodes in vacuum, the first photons to escape from its surface appear as a brief, hours-long shock-breakout flare1,2, followed by a cooling phase of emission. However, for stars exploding within a distribution of dense, optically thick circumstellar material (CSM), the first photons escape from the material beyond the stellar edge and the duration of the initial flare can extend to several days, during which the escaping emission indicates photospheric heating3. Early serendipitous observations2,4 that lacked ultraviolet (UV) data were unable to determine whether the early emission is heating or cooling and hence the nature of the early explosion event. Here we report UV spectra of the nearby SN 2023ixf in the galaxy Messier 101 (M101). Using the UV data as well as a comprehensive set of further multiwavelength observations, we temporally resolve the emergence of the explosion shock from a thick medium heated by the SN emission. We derive a reliable bolometric light curve that indicates that the shock breaks out from a dense layer with a radius substantially larger than typical supergiants.

2.
Phys Rev Lett ; 129(20): 201801, 2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36461983

RESUMO

This Letter presents the results from the MiniBooNE experiment within a full "3+1" scenario where one sterile neutrino is introduced to the three-active-neutrino picture. In addition to electron-neutrino appearance at short baselines, this scenario also allows for disappearance of the muon-neutrino and electron-neutrino fluxes in the Booster Neutrino Beam, which is shared by the MicroBooNE experiment. We present the 3+1 fit to the MiniBooNE electron-(anti)neutrino and muon-(anti)neutrino data alone and in combination with MicroBooNE electron-neutrino data. The best-fit parameters of the combined fit with the exclusive charged-current quasielastic analysis (inclusive analysis) are Δm^{2}=0.209 eV^{2}(0.033 eV^{2}), |U_{e4}|^{2}=0.016(0.500), |U_{µ4}|^{2}=0.500(0.500), and sin^{2}(2θ_{µe})=0.0316(1.0). Comparing the no-oscillation scenario to the 3+1 model, the data prefer the 3+1 model with a Δχ^{2}/d.o.f.=24.7/3(17.3/3), a 4.3σ(3.4σ) preference assuming the asymptotic approximation given by Wilks's theorem.

3.
Nature ; 601(7892): 201-204, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35022591

RESUMO

The final fate of massive stars, and the nature of the compact remnants they leave behind (black holes and neutron stars), are open questions in astrophysics. Many massive stars are stripped of their outer hydrogen envelopes as they evolve. Such Wolf-Rayet stars1 emit strong and rapidly expanding winds with speeds greater than 1,000 kilometres per second. A fraction of this population is also helium-depleted, with spectra dominated by highly ionized emission lines of carbon and oxygen (types WC/WO). Evidence indicates that the most commonly observed supernova explosions that lack hydrogen and helium (types Ib/Ic) cannot result from massive WC/WO stars2,3, leading some to suggest that most such stars collapse directly into black holes without a visible supernova explosion4. Here we report observations of SN 2019hgp, beginning about a day after the explosion. Its short rise time and rapid decline place it among an emerging population of rapidly evolving transients5-8. Spectroscopy reveals a rich set of emission lines indicating that the explosion occurred within a nebula composed of carbon, oxygen and neon. Narrow absorption features show that this material is expanding at high velocities (greater than 1,500 kilometres per second), requiring a compact progenitor. Our observations are consistent with an explosion of a massive WC/WO star, and suggest that massive Wolf-Rayet stars may be the progenitors of some rapidly evolving transients.

4.
Phys Rev Lett ; 121(22): 221801, 2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-30547637

RESUMO

The MiniBooNE experiment at Fermilab reports results from an analysis of ν_{e} appearance data from 12.84×10^{20} protons on target in neutrino mode, an increase of approximately a factor of 2 over previously reported results. A ν_{e} charged-current quasielastic event excess of 381.2±85.2 events (4.5σ) is observed in the energy range 200

5.
Phys Rev Lett ; 120(14): 141802, 2018 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-29694148

RESUMO

We report the first measurement of monoenergetic muon neutrino charged current interactions. MiniBooNE has isolated 236 MeV muon neutrino events originating from charged kaon decay at rest (K^{+}→µ^{+}ν_{µ}) at the NuMI beamline absorber. These signal ν_{µ}-carbon events are distinguished from primarily pion decay in flight ν_{µ} and ν[over ¯]_{µ} backgrounds produced at the target station and decay pipe using their arrival time and reconstructed muon energy. The significance of the signal observation is at the 3.9σ level. The muon kinetic energy, neutrino-nucleus energy transfer (ω=E_{ν}-E_{µ}), and total cross section for these events are extracted. This result is the first known-energy, weak-interaction-only probe of the nucleus to yield a measurement of ω using neutrinos, a quantity thus far only accessible through electron scattering.

6.
J Perinatol ; 35(11): 895-9, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26181720

RESUMO

Nipple confusion, an infant's difficulty with or preference for one feeding mechanism over another after exposure to artificial nipple(s), has been widely debated. This is in part due to conflicting statements, one by the American Academy of Pediatrics in 2005 suggesting that infants should be given a pacifier to protect against Sudden Infant Death Syndrome, and the other by the World Health Organization in 2009 stating that breastfeeding infants should never be given artificial nipples. Despite the limited and inconsistent evidence, nipple confusion is widely believed by practitioners. Therefore, there is a unique opportunity to examine the evidence surrounding nipple confusion by assessing the research that supports/refutes that bottle feeding/pacifier use impedes breastfeeding efficacy/success/duration. This review examined 14 articles supporting and refuting nipple confusion. These articles were reviewed using the Johns Hopkins Nursing Evidence-Based Practice Rating Scale. Based on our review, we have found emerging evidence to suggest the presence of nipple confusion only as it relates to bottle usage and found very little evidence to support nipple confusion with regards to pacifier use. The primary difficulty in conclusively studying nipple confusion is establishing causality, namely determining whether bottles'/pacifiers' nipples are causing infants to refuse the breast or whether they are simply markers of other maternal/infant characteristics. Future research should focus on prospectively examining the causality of nipple confusion.


Assuntos
Alimentação com Mamadeira/psicologia , Aleitamento Materno/psicologia , Recém-Nascido/fisiologia , Mamilos , Comportamento de Sucção/fisiologia , Adulto , Alimentação com Mamadeira/métodos , Aleitamento Materno/métodos , Feminino , Humanos , Chupetas
7.
Phys Rev Lett ; 110(16): 161801, 2013 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-23679593

RESUMO

The MiniBooNE experiment at Fermilab reports results from an analysis of ν[over ¯](e) appearance data from 11.27×10(20) protons on target in the antineutrino mode, an increase of approximately a factor of 2 over the previously reported results. An event excess of 78.4±28.5 events (2.8σ) is observed in the energy range 200

8.
Age (Dordr) ; 35(6): 2137-52, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23340916

RESUMO

Consistent daily rhythms are important to healthy aging according to studies linking disrupted circadian rhythms with negative health impacts. We studied the effects of age and exercise on baseline circadian rhythms and on the circadian system's ability to respond to the perturbation induced by an 8 h advance of the light:dark (LD) cycle as a test of the system's robustness. Mice (male, mPer2(luc)/C57BL/6) were studied at one of two ages: 3.5 months (n = 39) and >18 months (n = 72). We examined activity records of these mice under entrained and shifted conditions as well as mPER2::LUC measures ex vivo to assess circadian function in the suprachiasmatic nuclei (SCN) and important target organs. Age was associated with reduced running wheel use, fragmentation of activity, and slowed resetting in both behavioral and molecular measures. Furthermore, we observed that for aged mice, the presence of a running wheel altered the amplitude of the spontaneous firing rate rhythm in the SCN in vitro. Following a shift of the LD cycle, both young and aged mice showed a change in rhythmicity properties of the mPER2::LUC oscillation of the SCN in vitro, and aged mice exhibited longer lasting internal desynchrony. Access to a running wheel alleviated some age-related changes in the circadian system. In an additional experiment, we replicated the effect of the running wheel, comparing behavioral and in vitro results from aged mice housed with or without a running wheel (>21 months, n = 8 per group, all examined 4 days after the shift). The impact of voluntary exercise on circadian rhythm properties in an aged animal is a novel finding and has implications for the health of older people living with environmentally induced circadian disruption.


Assuntos
Envelhecimento/fisiologia , Ritmo Circadiano/fisiologia , Condicionamento Físico Animal/fisiologia , Esforço Físico/fisiologia , Núcleo Supraquiasmático/fisiologia , Animais , Comportamento Animal/fisiologia , Seguimentos , Locomoção/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL
9.
J Perinatol ; 33(1): 3-8, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22878560

RESUMO

Majority of hearing-loss cases with extremely preterm infants have no known etiology. There is a growing concern that the administration of aminoglycoside treatment in the noisy environment of the Neonatal Intensive Care Unit (NICU) may lead to hair-cell damage and subsequent auditory impairments. In addition, several mitochondrial DNA mutations are known to have been associated with aminoglycoside-induced hearing loss. This review provides a systematic analysis of the research in this area and elucidates the multifactorial mechanisms behind how mitochondrial DNA mutations, aminoglycosides and loud noise can potentiate ototoxicity in extremely preterm neonates. Recommended steps to minimize the risk of ototoxicity and improve clinical care for NICU infants are discussed.


Assuntos
Aminoglicosídeos/toxicidade , Antibacterianos/toxicidade , Perda Auditiva Provocada por Ruído/etiologia , Perda Auditiva/induzido quimicamente , Perda Auditiva/genética , Recém-Nascido de Peso Extremamente Baixo ao Nascer , Doenças do Prematuro/etiologia , Unidades de Terapia Intensiva Neonatal , Aminoglicosídeos/uso terapêutico , Antibacterianos/uso terapêutico , Análise Mutacional de DNA , DNA Mitocondrial/genética , Células Ciliadas Auditivas/efeitos dos fármacos , Perda Auditiva/prevenção & controle , Perda Auditiva Provocada por Ruído/prevenção & controle , Humanos , Recém-Nascido , Doenças do Prematuro/induzido quimicamente , Doenças do Prematuro/genética , Doenças do Prematuro/prevenção & controle , Ruído/efeitos adversos , Fatores de Risco
10.
J Perinatol ; 32(8): 614-20, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22157627

RESUMO

OBJECTIVE: To examine the role of vestibular inputs on respiratory and oromotor systems in healthy preterm infants. STUDY DESIGN: A total of 27 preterm infants were quasi-randomly assigned to either the VestibuGlide treatment or control groups. VestibuGlide infants were held in a developmentally supportive position, given a pacifier and received a series of vestibular stimuli, counterbalanced across rate and acceleration conditions, 15 min 3 times per day for 10 days. The control infants were also held in a developmentally supportive position, given a pacifier for 15 min 3 times per day for 10 days but did not receive the VestibuGlide stimulation. RESULT: A multi-level regression model revealed that treatment infants increased their respiratory rate in response to vestibular stimulus, and that the highest level of vestibular acceleration delivered to the infants (0.51 ms(-2)) resulted in a significant increase in breaths per minute. CONCLUSION: Vestibular stimulation delivered to preterm infants before scheduled feeds effectively modulates respiratory rate and resets the respiratory central pattern generator.


Assuntos
Geradores de Padrão Central/fisiologia , Recém-Nascido Prematuro/fisiologia , Parede Torácica/fisiologia , Vestíbulo do Labirinto/fisiologia , Aceleração , Análise de Variância , Fenômenos Biomecânicos , Feminino , Humanos , Recém-Nascido , Masculino , Fenômenos Fisiológicos Respiratórios
11.
Phys Rev Lett ; 107(20): 201803, 2011 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-22181724

RESUMO

The KTeV E799 experiment has conducted a search for the rare decays, K(L)→π(0)π(0)µ(+)µ(-) and K(L)→π(0)π(0)X(0)→π(0)π(0)µ(+)µ(-), where the X(0) is a possible new neutral boson that was reported by the HyperCP experiment with a mass of (214.3 ± 0.5) MeV/c(2). We find no evidence for either decay. We obtain upper limits of Br(K(L)→π(0)π(0)X(0)→π(0)π(0)µ(+)µ(-)) < 1.0 × 10(-10) and Br(K(L)→π(0)π(0)µ(+)µ(-)) < 9.2 × 10(-11) at the 90% confidence level. This result rules out the pseudoscalar X(0) as an explanation of the HyperCP result under the scenario that the dsX(0) coupling is completely real.

12.
J Evol Biol ; 23(7): 1519-27, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20492090

RESUMO

Arbuscular mycorrhizal fungi (AMF) are heterokaryotes with an unusual genetic makeup. Substantial genetic variation occurs among nuclei within a single mycelium or isolate. AMF reproduce through spores that contain varying fractions of this heterogeneous population of nuclei. It is not clear whether this genetic variation on the genome level actually contributes to the AMF phenotype. To investigate the extent to which polymorphisms in nuclear genes are transcribed, we analysed the intra-isolate genomic and cDNA sequence variation of two genes, the large subunit ribosomal RNA (LSU rDNA) of Glomus sp. DAOM-197198 (previously known as G. intraradices) and the POL1-like sequence (PLS) of Glomus etunicatum. For both genes, we find high sequence variation at the genome and transcriptome level. Reconstruction of LSU rDNA secondary structure shows that all variants are functional. Patterns of PLS sequence polymorphism indicate that there is one functional gene copy, PLS2, which is preferentially transcribed, and one gene copy, PLS1, which is a pseudogene. This is the first study that investigates AMF intra-isolate variation at the transcriptome level. In conclusion, it is possible that, in AMF, multiple nuclear genomes contribute to a single phenotype.


Assuntos
Perfilação da Expressão Gênica , Variação Genética , Genoma Fúngico/genética , Glomeromycota/genética , Micorrizas/genética , Fenótipo , Sequência de Bases , DNA Polimerase I/genética , Primers do DNA/genética , DNA Complementar/genética , Dados de Sequência Molecular , Subunidades Ribossômicas Maiores/genética , Alinhamento de Sequência , Análise de Sequência de DNA
13.
Phys Rev Lett ; 100(13): 131803, 2008 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-18517936

RESUMO

The Fermilab KTeV experiment has searched for lepton-flavor-violating decays of the K(L) meson in three decay modes. We observe no events in the signal region for any of the modes studied, and we set the following upper limits for their branching ratios at the 90% C.L.: BR(K(L) --> pi(0) micro(+/-) e(-/+)) <7.6 x 10(-11); BR(K(L) --> pi(0)pi(0) micro(+/-) e(-/+)) <1.7 x 10(-10); BR(pi(0) --> micro(+/-) e(-/+)) <3.6 x 10(-10). This result represents a factor of 82 improvement in the branching ratio limit for K(L) --> pi(0) micro(+/-) e(-/+) and is the first reported limit for K(L) --> pi(0)pi(0) micro(+/-) e(-/+).

14.
Phys Rev Lett ; 100(18): 182001, 2008 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-18518364

RESUMO

We present a new determination of the parity of the neutral pion via the double Dalitz decay pi0-->e+e-e+e-. Our sample, which consists of 30,511 candidate decays, was collected from KL-->pi0pi0pi0 decays in flight at the KTeV-E799 experiment at Fermi National Accelerator Laboratory. We confirm the negative pi0 parity and place a limit on scalar contributions to the pi0-->e+e-e+e- decay amplitude of less than 3.3% assuming CPT conservation. The pi0gamma*gamma* form factor is well described by a momentum-dependent model with a slope parameter fit to the final state phase-space distribution. Additionally, we have measured the branching ratio of this mode to be B(pi0-->e+e-e+e-)=(3.26+/-0.18)x10(-5).

15.
Acta Paediatr ; 97(7): 920-7, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18462468

RESUMO

AIM: To determine whether NTrainer patterned orocutaneous therapy affects preterm infants' non-nutritive suck and/or oral feeding success. SUBJECTS: Thirty-one preterm infants (mean gestational age 29.3 weeks) who demonstrated minimal non-nutritive suck output and delayed transition to oral feeds at 34 weeks post-menstrual age. INTERVENTION: NTrainer treatment was provided to 21 infants. The NTrainer promotes non-nutritive suck output by providing patterned orocutaneous stimulation through a silicone pacifier that mimics the temporal organization of suck. METHOD: Infants' non-nutritive suck pressure signals were digitized in the NICU before and after NTrainer therapy and compared to matched controls. Non-nutritive suck motor pattern stability was calculated based on infants' time- and amplitude-normalized digital suck pressure signals, producing a single value termed the Non-Nutritive Suck Spatiotemporal Index. Percent oral feeding was the other outcome of interest, and revealed the NTrainer's ability to advance the infant from gavage to oral feeding. RESULTS: Multilevel regression analyses revealed that treated infants manifest a disproportionate increase in suck pattern stability and percent oral feeding, beyond that attributed to maturational effects alone. CONCLUSION: The NTrainer patterned orocutaneous therapy effectively accelerates non-nutritive suck development and oral feeding success in preterm infants who are at risk for oromotor dysfunction.


Assuntos
Comportamento Alimentar , Recém-Nascido Prematuro/fisiologia , Estimulação Física , Comportamento de Sucção , Feminino , Humanos , Recém-Nascido , Masculino , Chupetas
16.
Neurology ; 70(18): 1614-9, 2008 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-18443312

RESUMO

BACKGROUND: Neurodegeneration with brain iron accumulation (NBIA) defines a group of genetic disorders characterized by brain iron deposition and associated with neuronal death. The known causes of NBIA include pantothenate kinase-associated neurodegeneration (PKAN), neuroferritinopathy, infantile neuroaxonal dystrophy (INAD), and aceruloplasminemia. OBJECTIVE: To define the radiologic features of each NBIA subtype. METHODS: Brain MRIs from patients with molecularly confirmed PKAN (26 cases), neuroferritinopathy (21 cases), INAD (four cases), and aceruloplasminemia (10 cases) were analyzed blindly to delineate patterns of iron deposition and neurodegeneration. RESULTS: In most cases of PKAN, abnormalities were restricted to globus pallidus and substantia nigra, with 100% having an eye of the tiger sign. In a minority of PKAN cases there was hypointensity of the dentate nuclei (1/5 on T2* sequences, 2/26 on fast spin echo [FSE]). In INAD, globus pallidus and substantia nigra were involved on T2* and FSE scans, with dentate involvement only seen on T2*. By contrast, neuroferritinopathy had consistent involvement of the dentate nuclei, globus pallidus, and putamen, with confluent areas of hyperintensity due to probable cavitation, involving the pallida and putamen in 52%, and a subset having lesions in caudate nuclei and thalami. More uniform involvement of all basal ganglia and the thalami was typical in aceruloplasminemia, but without cavitation. CONCLUSIONS: In the majority of cases, different subtypes of neurodegeneration associated with brain iron accumulation can be reliably distinguished with T2* and T2 fast spin echo brain MRI, leading to accurate clinical and subsequent molecular diagnosis.


Assuntos
Química Encefálica , Ferro/análise , Imageamento por Ressonância Magnética/métodos , Doenças Neurodegenerativas/diagnóstico , Adolescente , Adulto , Idoso , Apoferritinas , Ceruloplasmina/deficiência , Criança , Pré-Escolar , Diagnóstico Diferencial , Europa (Continente) , Feminino , Ferritinas/genética , Fosfolipases A2 do Grupo VI/deficiência , Fosfolipases A2 do Grupo VI/genética , Humanos , Masculino , Pessoa de Meia-Idade , Distrofias Neuroaxonais/diagnóstico , Distrofias Neuroaxonais/genética , Distrofias Neuroaxonais/metabolismo , Distrofias Neuroaxonais/patologia , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , América do Norte , Fosfotransferases (Aceptor do Grupo Álcool)/deficiência , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Estudos Retrospectivos
17.
Phys Rev Lett ; 99(5): 051804, 2007 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-17930743

RESUMO

The E799-II (KTeV) experiment at Fermilab has collected 83 262 K(L)-->e+ e- gamma(gamma) events above a background of 79 events. We measure a decay width, normalized to the K(L)-->pi0pi0pi(D)0 (pi0-->gammagamma, pi0-->gammagamma, pi(D0-->e+ e- gamma(gamma)) decay width, of Gamma(K(L)-->e+e-gamma(gamma))/Gamma(K(L)-->pi0pi0pi(D)0)=(1.3302+/-0.0046(stat)+/-0.0102(syst)) x 10(-3). We also measure parameters of two K(L)gamma*gamma form factor models. In the Bergström-Massó-Singer parametrization, we find Calpha(K*)= -0.517 +/- 0.030(stat) +/- 0.022(syst). We separately fit for the first parameter of the D'Ambrosio-Isidori-Portolés model and find alpha(DIP)= -1.729 +/- 0.043(stat) +/- 0.028(syst).

18.
Phys Rev Lett ; 99(8): 081803, 2007 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-17930940

RESUMO

This Letter is the first report of the K{L}-->pi{+/-}e{-/+}nue{+}e{-} decay. Based on 19 208+/-144 events, we determine the branching fraction, B(K{L}-->pi{+/-}e{-/+}nue{+}e{-}M_{e{+}e{-}}>5 MeV/c{2},E{e{+}e{-}}{*}>30 MeV)=(1.285+/-0.041)x10{-5}, and Gamma(K{e3ee}M{e{+}e{-}}>5 MeV/c{2})/Gamma(K{e3})=[4.57+/-0.04(stat)+/-0.14(syst)]x10{-5}. This ratio agrees with a theoretical prediction based on chiral perturbation theory (ChPT) calculated to O(p{4}). The measured kinematical distributions agree with those predicted by just ChPT O(p{4}), but show significant disagreement with ones predicted by leading-order ChPT.

19.
Phys Rev Lett ; 99(19): 192001, 2007 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-18233069

RESUMO

We present a new measurement of the difference between the nucleon strange and antistrange quark distributions from dimuon events recorded by the NuTeV experiment at Fermilab. This analysis is the first to use a complete next to leading order QCD description of charm production from neutrino scattering. Dimuon events in neutrino deep inelastic scattering allow direct and independent study of the strange and antistrange content of the nucleon. We find a positive strange asymmetry with a significance of 1.6sigma. We also report a new measurement of the charm mass.

20.
Cell Death Differ ; 12(4): 326-34, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15650754

RESUMO

The human immunodeficiency virus type-1 (HIV-1) accessory gene vpr encodes a conserved 96-amino-acid protein that is necessary and sufficient for the HIV-1-induced block of cellular proliferation. Expression of vpr in CD4+ lymphocytes results in G2 arrest, followed by apoptosis. In a previous study, we identified the ataxia telangiectasia-mutated (ATM) and Rad3-related protein (ATR) as a cellular factor that mediates Vpr-induced cell cycle arrest. In the present study, we report that the breast cancer-associated protein-1 (BRCA1), a known target of ATR, is activated in the presence of Vpr. In addition, the gene encoding the growth arrest and DNA damage-45 protein alpha (GADD45alpha), a known transcriptional target of BRCA1, is upregulated by Vpr in an ATR-dependent manner. We demonstrate that RNAi-mediated silencing of either ATR or GADD45alpha leads to nearly complete suppression of the proapoptotic effect of Vpr. Our results support a model in which Vpr-induced apoptosis is mediated via ATR phosphorylation of BRCA1, and consequent upregulation of GADD45alpha.


Assuntos
Apoptose/fisiologia , Proteínas de Ciclo Celular/metabolismo , Produtos do Gene vpr/metabolismo , HIV-1/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Mutadas de Ataxia Telangiectasia , Proteína BRCA1/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Inibidores de Caspase , Fase G2/fisiologia , Células HeLa , Humanos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosforilação , Serina/metabolismo , Subpopulações de Linfócitos T/metabolismo , Produtos do Gene vpr do Vírus da Imunodeficiência Humana
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