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1.
Proc Natl Acad Sci U S A ; 121(34): e2403133121, 2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39141346

RESUMEN

Polyomaviruses are small, circular dsDNA viruses that can cause cancer. Alternative splicing of polyomavirus early transcripts generates large and small tumor antigens (LT, ST) that play essential roles in viral replication and tumorigenesis. Some polyomaviruses also express middle tumor antigens (MTs) or alternate LT open reading frames (ALTOs), which are evolutionarily related but have distinct gene structures. MTs are a splice variant of the early transcript whereas ALTOs are overprinted on the second exon of the LT transcript in an alternate reading frame and are translated via an alternative start codon. Merkel cell polyomavirus (MCPyV), the only human polyomavirus that causes cancer, encodes an ALTO but its role in the viral lifecycle and tumorigenesis has remained elusive. Here, we show MCPyV ALTO acts as a tumor suppressor and is silenced in Merkel cell carcinoma (MCC). Rescuing ALTO in MCC cells induces growth arrest and activates NF-κB signaling. ALTO activates NF-κB by binding SQSTM1 and TRAF2&3 via two N-Terminal Activating Regions (NTAR1+2), resembling Epstein-Barr virus (EBV) Latent Membrane Protein 1 (LMP1). Following activation, NF-κB dimers bind the MCPyV noncoding control region (NCCR) and downregulate early transcription. Beyond MCPyV, NTAR motifs are conserved in other polyomavirus ALTOs, which activate NF-κB signaling, but are lacking in MTs that do not. Furthermore, polyomavirus ALTOs downregulate their respective viral early transcription in an NF-κB- and NTAR-dependent manner. Our findings suggest that ALTOs evolved to suppress viral replication and promote viral latency and that MCPyV ALTO must be silenced for MCC to develop.


Asunto(s)
Regulación Viral de la Expresión Génica , FN-kappa B , Transducción de Señal , Humanos , FN-kappa B/metabolismo , Antígenos Virales de Tumores/genética , Antígenos Virales de Tumores/metabolismo , Poliomavirus de Células de Merkel/genética , Infecciones por Polyomavirus/virología , Infecciones por Polyomavirus/genética , Infecciones por Polyomavirus/metabolismo , Carcinoma de Células de Merkel/virología , Carcinoma de Células de Merkel/genética , Carcinoma de Células de Merkel/metabolismo , Sistemas de Lectura Abierta/genética , Línea Celular Tumoral , Regulación hacia Abajo , Empalme Alternativo
2.
Psychol Med ; 53(12): 5615-5624, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-36117279

RESUMEN

BACKGROUND: Sexual minority men (SMM) experience higher suicidal ideation and suicide attempts than the general population. We examined the associations of adverse childhood experiences (ACES) and protective and compensatory childhood experiences (PACES) with suicidal ideation and suicide attempts in adulthood via thwarted belongingness and perceived burdensomeness among SMM. METHODS: Data are from the UNITE study, a national longitudinal cohort study of HIV-negative SMM from the 50 U.S. states and Puerto Rico. Between 2017 and 2019, participants (N = 6303) completed web-based assessments at baseline and 12-month follow-up. ACES and PACES occurring before the age of 18, and current symptoms of thwarted belongingness and perceived burdensomeness were assessed at baseline. Past-week suicidal ideation and past-year suicide attempt were assessed at follow-up. RESULTS: 424 (6.7%) participants reported past-week suicidal ideation and 123 (2.0%) reported a past-year suicide attempt. The results of our multivariate model suggest that each additional adverse childhood experience was prospectively associated with 14% higher odds of past-week suicidal ideation (AOR = 1.14, 95% CI 1.09-1.19) and 19% higher odds of past-year suicide attempt (AOR = 1.19, 95% CI 1.11-1.29). Each additional protective childhood experience was prospectively associated with 15% lower odds of past-week suicidal ideation (AOR = 0.85, 95% CI 0.81-0.90) and 11% lower odds of past-year suicide attempt (AOR = 0.89, 95% CI 0.82-0.98). Perceived burdensomeness partially mediated these prospective associations. CONCLUSION: To reduce suicide, screening and treating perceived burdensomeness among SMM with high ACES may be warranted. PACES may decrease perceived burdensomeness and associated suicide risk.


Asunto(s)
Relaciones Interpersonales , Intento de Suicidio , Masculino , Humanos , Estudios Longitudinales , Ideación Suicida , Factores de Riesgo , Teoría Psicológica
3.
Am J Public Health ; 112(S4): S413-S419, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35763749

RESUMEN

Researchers are increasingly recognizing the importance of studying and addressing intersectional stigma within the field of HIV. Yet, researchers have, arguably, struggled to operationalize intersectional stigma. To ensure that future research and methodological innovation is guided by frameworks from which this area of inquiry has arisen, we propose a series of core elements for future HIV-related intersectional stigma research. These core elements include multidimensional, multilevel, multidirectional, and action-oriented methods that sharpen focus on, and aim to transform, interlocking and reinforcing systems of oppression. We further identify opportunities for advancing HIV-related intersectional stigma research, including reducing barriers to and strengthening investments in resources, building capacity to engage in research and implementation of interventions, and creating meaningful pathways for HIV-related intersectional stigma research to produce structural change. Ultimately, the expected payoff for incorporating these core elements is a body of HIV-related intersectional stigma research that is both better aligned with the transformative potential of intersectionality and better positioned to achieve the goals of Ending the HIV Epidemic in the United States and globally. (Am J Public Health. 2022;112(S4):S413-S419. https://doi.org/10.2105/AJPH.2021.306710).


Asunto(s)
Infecciones por VIH , Trastornos Mentales , Infecciones por VIH/epidemiología , Humanos , Estigma Social , Estados Unidos
4.
J Res Adolesc ; 32(1): 226-243, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35166417

RESUMEN

This study examined associations between structural racism, anti-LGBTQ policies, and suicide risk among young sexual minority men (SMM). Participants were a 2017-2018 Internet-based U.S. national sample of 497 Black and 1536 White SMM (ages 16-25). Structural equation modeling tested associations from indicators of structural racism, anti-LGBTQ policies, and their interaction to suicide risk factors. For Black participants, structural racism and anti-LGBTQ policies were significantly positively associated with depressive symptoms, heavy drinking, perceived burdensomeness, thwarted belongingness, self-harm, and suicide attempt. There were significant interaction effects: Positive associations between structural racism and several outcomes were stronger for Black participants in high anti-LGBTQ policy states. Structural racism, anti-LGBTQ policies, and their interaction were not significantly associated with suicide risk for White SMM.


Asunto(s)
Minorías Sexuales y de Género , Suicidio , Adolescente , Adulto , Humanos , Masculino , Relaciones Raciales , Ideación Suicida , Intento de Suicidio , Adulto Joven
5.
Nat Mater ; 19(1): 86-93, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31844281

RESUMEN

The efficient production of light olefins from renewable biomass is a vital and challenging target to achieve future sustainable chemical processes. Here we report a hetero-atomic MFI-type zeolite (NbAlS-1), over which aqueous solutions of γ-valerolactone (GVL), obtained from biomass-derived carbohydrates, can be quantitatively converted into butenes with a yield of >99% at ambient pressure under continuous flow conditions. NbAlS-1 incorporates simultaneously niobium(V) and aluminium(III) centres into the framework and thus has a desirable distribution of Lewis and Brønsted acid sites with optimal strength. Synchrotron X-ray diffraction and absorption spectroscopy show that there is cooperativity between Nb(V) and the Brønsted acid sites on the confined adsorption of GVL, whereas the catalytic mechanism for the conversion of the confined GVL into butenes is revealed by in situ inelastic neutron scattering, coupled with modelling. This study offers a prospect for the sustainable production of butene as a platform chemical for the manufacture of renewable materials.


Asunto(s)
Alquenos/química , Lactonas/química , Zeolitas/química , Adsorción , Biomasa , Carbohidratos/química , Catálisis , Enlace de Hidrógeno , Ensayo de Materiales , Neutrones , Dispersión de Radiación , Espectroscopía Infrarroja por Transformada de Fourier , Sincrotrones
6.
Angew Chem Int Ed Engl ; 60(28): 15243-15247, 2021 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-33848040

RESUMEN

Selective oxidation of benzylic C-H compounds to ketones is important for the production of a wide range of fine chemicals, and is often achieved using toxic or precious metal catalysts. Herein, we report the efficient oxidation of benzylic C-H groups in a broad range of substrates under mild conditions over a robust metal-organic framework material, MFM-170, incorporating redox-active [Cu2 II (O2 CR)4 ] paddlewheel nodes. A comprehensive investigation employing electron paramagnetic resonance (EPR) spectroscopy and synchrotron X-ray diffraction has identified the critical role of the paddlewheel moiety in activating the oxidant t BuOOH (tert-butyl hydroperoxide) via partial reduction to [CuII CuI (O2 CR)4 ] species.

7.
J Infect Dis ; 217(4): 572-580, 2018 01 30.
Artículo en Inglés | MEDLINE | ID: mdl-29186468

RESUMEN

Current guidance recommends that adolescents receive a 2-dose human papillomavirus (HPV) vaccine, whereas young adults and immunocompromised persons receive 3 doses. We examined secondary responses of vaccine-elicited memory B cells (Bmem) in naive women receiving 3 doses of the quadrivalent HPV vaccine to understand the quality of B-cell memory generated by this highly effective vaccine. Unexpectedly, we observed a lower Bmem response rate and magnitude of Bmem responses to the third dose than to a booster dose administered at month 24. Moreover, high titers of antigen-specific serum antibody at vaccination inversely correlated with Bmem responses. As the purpose of additional doses/boosters is to stimulate Bmem to rapidly boost antibody levels, these results indicate the timing of the third dose is suboptimal and lend support to a 2-dose HPV vaccine for young adults. Our findings also indicate more broadly that multidose vaccine schedules should be rationally determined on the basis of Bmem responses.


Asunto(s)
Anticuerpos Antivirales/sangre , Formación de Anticuerpos , Linfocitos B/inmunología , Vacuna Tetravalente Recombinante contra el Virus del Papiloma Humano Tipos 6, 11 , 16, 18/administración & dosificación , Vacuna Tetravalente Recombinante contra el Virus del Papiloma Humano Tipos 6, 11 , 16, 18/inmunología , Esquemas de Inmunización , Adolescente , Adulto , Femenino , Humanos , Proyectos Piloto , Adulto Joven
8.
J Am Chem Soc ; 140(46): 15564-15567, 2018 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-30418751

RESUMEN

We report a record-high SO2 adsorption capacity of 12.3 mmol g-1 in a robust porous material, MFM-601, at 298 K and 1.0 bar. SO2 adsorption in MFM-601 is fully reversible and highly selective over CO2 and N2. The binding domains for adsorbed SO2 and CO2 molecules in MFM-601 have been determined by in situ synchrotron X-ray diffraction experiments, giving insights at the molecular level to the basis of the observed high selectivity.

9.
Angew Chem Int Ed Engl ; 57(45): 14778-14781, 2018 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-30098090

RESUMEN

MFM-300(Al) shows reversible uptake of NH3 (15.7 mmol g-1 at 273 K and 1.0 bar) over 50 cycles with an exceptional packing density of 0.62 g cm-3 at 293 K. In situ neutron powder diffraction and synchrotron FTIR micro-spectroscopy on ND3 @MFM-300(Al) confirms reversible H/D site exchange between the adsorbent and adsorbate, representing a new type of adsorption interaction.

10.
Cancer ; 123(8): 1464-1474, 2017 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-27925665

RESUMEN

BACKGROUND: Merkel cell carcinoma (MCC) is an aggressive skin cancer with a recurrence rate of >40%. Of the 2000 MCC cases per year in the United States, most are caused by the Merkel cell polyomavirus (MCPyV). Antibodies to MCPyV oncoprotein (T-antigens) have been correlated with MCC tumor burden. The present study assesses the clinical utility of MCPyV-oncoprotein antibody titers for MCC prognostication and surveillance. METHODS: MCPyV-oncoprotein antibody detection was optimized in a clinical laboratory. A cohort of 219 patients with newly diagnosed MCC were followed prospectively (median follow-up, 1.9 years). Among the seropositive patients, antibody titer and disease status were serially tracked. RESULTS: Antibodies to MCPyV oncoproteins were rare among healthy individuals (1%) but were present in most patients with MCC (114 of 219 patients [52%]; P < .01). Seropositivity at diagnosis independently predicted decreased recurrence risk (hazard ratio, 0.58; P = .04) in multivariate analyses adjusted for age, sex, stage, and immunosuppression. After initial treatment, seropositive patients whose disease did not recur had rapidly falling titers that became negative by a median of 8.4 months. Among seropositive patients who underwent serial evaluation (71 patients; 282 time points), an increasing oncoprotein titer had a positive predictive value of 66% for clinically evident recurrence, whereas a decreasing titer had a negative predictive value of 97%. CONCLUSIONS: Determination of oncoprotein antibody titer assists in the clinical management of patients with newly diagnosed MCC by stratifying them into a higher risk seronegative cohort, in which radiologic imaging may play a more prominent role, and into a lower risk seropositive cohort, in which disease status can be tracked in part by oncoprotein antibody titer. Cancer 2017;123:1464-1474. © 2016 American Cancer Society.


Asunto(s)
Anticuerpos Antivirales/inmunología , Carcinoma de Células de Merkel/diagnóstico , Carcinoma de Células de Merkel/etiología , Proteínas Oncogénicas Virales/inmunología , Anciano , Anciano de 80 o más Años , Anticuerpos Antivirales/sangre , Biomarcadores , Carcinoma de Células de Merkel/epidemiología , Carcinoma de Células de Merkel/mortalidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Estadificación de Neoplasias , Vigilancia de la Población , Estudios Prospectivos , Reproducibilidad de los Resultados , Estudios Seroepidemiológicos , Infecciones Tumorales por Virus/complicaciones , Infecciones Tumorales por Virus/inmunología , Infecciones Tumorales por Virus/virología
14.
J Am Chem Soc ; 138(29): 9119-27, 2016 07 27.
Artículo en Inglés | MEDLINE | ID: mdl-27410670

RESUMEN

The key requirement for a portable store of natural gas is to maximize the amount of gas within the smallest possible space. The packing of methane (CH4) in a given storage medium at the highest possible density is, therefore, a highly desirable but challenging target. We report a microporous hydroxyl-decorated material, MFM-300(In) (MFM = Manchester Framework Material, replacing the NOTT designation), which displays a high volumetric uptake of 202 v/v at 298 K and 35 bar for CH4 and 488 v/v at 77 K and 20 bar for H2. Direct observation and quantification of the location, binding, and rotational modes of adsorbed CH4 and H2 molecules within this host have been achieved, using neutron diffraction and inelastic neutron scattering experiments, coupled with density functional theory (DFT) modeling. These complementary techniques reveal a very efficient packing of H2 and CH4 molecules within MFM-300(In), reminiscent of the condensed gas in pure component crystalline solids. We also report here, for the first time, the experimental observation of a direct binding interaction between adsorbed CH4 molecules and the hydroxyl groups within the pore of a material. This is different from the arrangement found in CH4/water clathrates, the CH4 store of nature.

15.
Int J Cancer ; 139(10): 2201-12, 2016 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-27448488

RESUMEN

To understand high-risk (hr) human papillomavirus (HPV) epidemiology in mid-adulthood, we assessed whether associations between incident detection of hrHPV DNA and recent sexual behavior differed according to whether or not there was serologic evidence of prior infection. From 2011 to 2012, we enrolled 409 women aged 30-50 years into a 6-month longitudinal study. We collected health and sexual behavior histories, enrollment sera for HPV antibody testing, and monthly self-collected vaginal swabs for HPV DNA genotyping. Generalized estimating equations logistic regression identified risk factors for type-specific incident hrHPV DNA, stratified by type-specific hrHPV serostatus at enrollment. Population attributable risks of hrHPV due to prior and recent exposure were estimated. When type-specific hrHPV serology was negative, recent sexual risk behavior was positively associated with incident hrHPV DNA (odds ratio in women reporting ≥3 recent sexual risk behaviors [e.g., new or multiple partners] vs. no recent sexual activity = 9.8, 95% CI: 2.4-40.6). No associations with recent sexual behavior were observed with positive type-specific hrHPV serology. Thirty percent of incident hrHPV DNA detection was attributable to prior infection (with positive serology) and 40% was attributable to recent sexual risk behavior (with negative serology). The proportion of incident hrHPV DNA detection attributable to recent sexual risk behavior decreased with increasing age. Among women with serologic evidence of prior infection, re-detection of the same hrHPV type is likely due to reactivation or intermittent detection of persistent infection. Without serologic evidence of prior infection, new detection is likely due to new acquisition or to intermittent detection of persisting infection.


Asunto(s)
Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/transmisión , Infecciones por Papillomavirus/virología , Enfermedades Virales de Transmisión Sexual/virología , Adulto , Factores de Edad , Femenino , Humanos , Estudios Longitudinales , Infecciones por Papillomavirus/diagnóstico , Infecciones por Papillomavirus/epidemiología , Enfermedades Virales de Transmisión Sexual/diagnóstico , Enfermedades Virales de Transmisión Sexual/epidemiología , Enfermedades Virales de Transmisión Sexual/transmisión , Washingtón/epidemiología , Adulto Joven
16.
PLoS Pathog ; 10(10): e1004461, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25330199

RESUMEN

Licensed human papillomavirus (HPV) vaccines provide near complete protection against the types of HPV that most commonly cause anogenital and oropharyngeal cancers (HPV 16 and 18) when administered to individuals naive to these types. These vaccines, like most other prophylactic vaccines, appear to protect by generating antibodies. However, almost nothing is known about the immunological memory that forms following HPV vaccination, which is required for long-term immunity. Here, we have identified and isolated HPV 16-specific memory B cells from female adolescents and young women who received the quadrivalent HPV vaccine in the absence of pre-existing immunity, using fluorescently conjugated HPV 16 pseudoviruses to label antigen receptors on the surface of memory B cells. Antibodies cloned and expressed from these singly sorted HPV 16-pseudovirus labeled memory B cells were predominantly IgG (>IgA>IgM), utilized diverse variable genes, and potently neutralized HPV 16 pseudoviruses in vitro despite possessing only average levels of somatic mutation. These findings suggest that the quadrivalent HPV vaccine provides an excellent model for studying the development of B cell memory; and, in the context of what is known about memory B cells elicited by influenza vaccination/infection, HIV-1 infection, or tetanus toxoid vaccination, indicates that extensive somatic hypermutation is not required to achieve potent vaccine-specific neutralizing antibody responses.


Asunto(s)
Linfocitos B/virología , Papillomavirus Humano 16 , Memoria Inmunológica/inmunología , Vacunas contra Papillomavirus/uso terapéutico , Adolescente , Enfermedades Transmisibles , Femenino , Infecciones por VIH/virología , VIH-1 , Humanos , Vacunación/métodos
17.
Sex Transm Dis ; 43(3): 192-8, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26859807

RESUMEN

BACKGROUND: The epidemiology of high-risk human papillomavirus (hrHPV) infections in mid-adult women is not well understood. METHODS: We conducted a cross-sectional analysis of 379 women 30 to 50 years of age. Vaginal samples were tested for type-specific HPV DNA by polymerase chain reaction. Sera were tested for type-specific HPV antibodies by Luminex-based assay. Assays included 13 hrHPV types (16/18/31/33/35/39/45/51/52/56/58/59/68). Self-reported health and sexual history were ascertained. Risk factors for seropositivity and DNA positivity to hrHPV were assessed in separate Poisson regression models. RESULTS: The mean (SD) age of participants was 38.7 (6.1) years, and the median lifetime number of male sex partners was 7. Approximately two-thirds (68.1%) were seropositive for any hrHPV, 15.0% were DNA positive, and 70.7% were seropositive or DNA positive. In multivariate analyses, women who were married/living with a partner were less likely to be seropositive than single/separated women (adjusted prevalence ratio [aPR], 0.86; 95% confidence interval [CI], 0.75-0.98). Compared with never hormonal contraceptive users, current (aPR, 1.53; 95% CI, 1.01-2.29) or former (aPR, 1.64; 95% CI, 1.10-2.45) users were more likely to be seropositive. Women with a lifetime number of sex partners of 12 or more were more likely to be seropositive compared with those with 0 to 4 partners (aPR, 1.29; 95% CI, 1.06-1.56). Similar associations were seen with DNA positivity. In addition, there was a positive association between current smoking and hrHPV DNA (aPR vs. never smokers, 2.51; 95% CI, 1.40-4.49). CONCLUSIONS: Seventy-one percent of mid-adult women had evidence of current or prior hrHPV infection. Measures of probable increased exposure to HPV infection were associated with both seropositivity and DNA positivity to hrHPV, whereas current smoking was positively associated with hrHPV DNA only.


Asunto(s)
Anticuerpos Antivirales/análisis , ADN Viral/análisis , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/epidemiología , Conducta Sexual/estadística & datos numéricos , Salud de la Mujer , Adulto , Anticuerpos Antivirales/genética , Estudios Transversales , ADN Viral/genética , Femenino , Humanos , Persona de Mediana Edad , Infecciones por Papillomavirus/complicaciones , Infecciones por Papillomavirus/prevención & control , Reacción en Cadena de la Polimerasa , Factores de Riesgo , Estudios Seroepidemiológicos , Parejas Sexuales
18.
BMC Cancer ; 16: 342, 2016 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-27246610

RESUMEN

BACKGROUND: Studies of human polyomavirus (HPyV) infection and lung cancer are limited and those regarding the association of human papillomavirus (HPV) infection and lung cancer have produced inconsistent results. METHODS: We conducted a nested case-control study to assess the association between incident lung cancer of various histologies and evidence of prior infection with HPyVs and HPVs. We selected serum from 183 cases and 217 frequency matched controls from the Yunnan Tin Miner's Cohort study, which was designed to identify biomarkers for early detection of lung cancer. Using multiplex liquid bead microarray (LBMA) antibody assays, we tested for antibodies to the VP1 structural protein and small T antigen (ST-Ag) of Merkel cell, KI, and WU HPyVs. We also tested for antibodies against HPV L1 structural proteins (high-risk types 16, 18, 31, 33, 52, and 58 and low-risk types 6 and 11) and E6 and E7 oncoproteins (high risk types 16 and 18). Measures of antibody reactivity were log transformed and analyzed using logistic regression. RESULTS: We found no association between KIV, WUV, and MCV antibody levels and incident lung cancer (P-corrected for multiple comparisons >0.10 for all trend tests). We also found no association with HPV-16, 18, 31, 33, 52, and 58 seropositivity (P-corrected for multiple comparisons >0.05 for all). CONCLUSIONS: Future studies of infectious etiologies of lung cancer should look beyond HPyVs and HPVs as candidate infectious agents.


Asunto(s)
Neoplasias Pulmonares/virología , Infecciones por Papillomavirus/epidemiología , Infecciones por Polyomavirus/epidemiología , Adulto , Anciano , Estudios de Casos y Controles , China/epidemiología , Femenino , Humanos , Incidencia , Neoplasias Pulmonares/epidemiología , Masculino , Persona de Mediana Edad , Infecciones por Papillomavirus/complicaciones , Infecciones por Polyomavirus/complicaciones
19.
J Chem Phys ; 145(12): 124307, 2016 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-27782641

RESUMEN

We investigate the low-energy transitions (0-570 cm-1) of the S1 state of para-fluorotoluene (pFT) using a combination of resonance-enhanced multiphoton ionization and zero-kinetic-energy (ZEKE) spectroscopy and quantum chemical calculations. By using various S1 states as intermediate levels, we obtain ZEKE spectra. The differing activity observed allows detailed assignments to be made of both the cation and S1 low-energy levels. The assignments are in line with the recently published work on toluene from the Lawrance group [J. R. Gascooke et al., J. Chem. Phys. 143, 044313 (2015)], which considered vibration-torsion coupling in depth for the S1 state of toluene. In addition, we investigate whether two bands that occur in the range 390-420 cm-1 are the result of a Fermi resonance; we present evidence for weak coupling between various vibrations and torsions that contribute to this region. This work has led to the identification of a number of misassignments in the literature, and these are corrected.

20.
Proc Natl Acad Sci U S A ; 110(31): 12744-9, 2013 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-23847207

RESUMEN

Many viruses use overprinting (alternate reading frame utilization) as a means to increase protein diversity in genomes severely constrained by size. However, the evolutionary steps that facilitate the de novo generation of a novel protein within an ancestral ORF have remained poorly characterized. Here, we describe the identification of an overprinting gene, expressed from an Alternate frame of the Large T Open reading frame (ALTO) in the early region of Merkel cell polyomavirus (MCPyV), the causative agent of most Merkel cell carcinomas. ALTO is expressed during, but not required for, replication of the MCPyV genome. Phylogenetic analysis reveals that ALTO is evolutionarily related to the middle T antigen of murine polyomavirus despite almost no sequence similarity. ALTO/MT arose de novo by overprinting of the second exon of T antigen in the common ancestor of a large clade of mammalian polyomaviruses. Taking advantage of the low evolutionary divergence and diverse sampling of polyomaviruses, we propose evolutionary transitions that likely gave birth to this protein. We suggest that two highly constrained regions of the large T antigen ORF provided a start codon and C-terminal hydrophobic motif necessary for cellular localization of ALTO. These two key features, together with stochastic erasure of intervening stop codons, resulted in a unique protein-coding capacity that has been preserved ever since its birth. Our study not only reveals a previously undefined protein encoded by several polyomaviruses including MCPyV, but also provides insight into de novo protein evolution.


Asunto(s)
Antígenos Virales de Tumores/genética , Codón Iniciador/genética , Evolución Molecular , Exones/fisiología , Poliomavirus de Células de Merkel/genética , Sistemas de Lectura Abierta/fisiología , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Antígenos Virales de Tumores/metabolismo , Codón Iniciador/metabolismo , Poliomavirus de Células de Merkel/metabolismo , Datos de Secuencia Molecular
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