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1.
Nature ; 585(7824): 256-260, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32848244

RESUMO

Temperature controls plant growth and development, and climate change has already altered the phenology of wild plants and crops1. However, the mechanisms by which plants sense temperature are not well understood. The evening complex is a major signalling hub and a core component of the plant circadian clock2,3. The evening complex acts as a temperature-responsive transcriptional repressor, providing rhythmicity and temperature responsiveness to growth through unknown mechanisms2,4-6. The evening complex consists of EARLY FLOWERING 3 (ELF3)4,7, a large scaffold protein and key component of temperature sensing; ELF4, a small α-helical protein; and LUX ARRYTHMO (LUX), a DNA-binding protein required to recruit the evening complex to transcriptional targets. ELF3 contains a polyglutamine (polyQ) repeat8-10, embedded within a predicted prion domain (PrD). Here we find that the length of the polyQ repeat correlates with thermal responsiveness. We show that ELF3 proteins in plants from hotter climates, with no detectable PrD, are active at high temperatures, and lack thermal responsiveness. The temperature sensitivity of ELF3 is also modulated by the levels of ELF4, indicating that ELF4 can stabilize the function of ELF3. In both Arabidopsis and a heterologous system, ELF3 fused with green fluorescent protein forms speckles within minutes in response to higher temperatures, in a PrD-dependent manner. A purified fragment encompassing the ELF3 PrD reversibly forms liquid droplets in response to increasing temperatures in vitro, indicating that these properties reflect a direct biophysical response conferred by the PrD. The ability of temperature to rapidly shift ELF3 between active and inactive states via phase transition represents a previously unknown thermosensory mechanism.


Assuntos
Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas Priônicas/química , Temperatura , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Aclimatação/fisiologia , Arabidopsis/química , Temperatura Alta , Modelos Moleculares , Peptídeos/metabolismo , Transição de Fase , Domínios Proteicos , Proteínas Repressoras/química , Proteínas Repressoras/metabolismo
2.
Vaccine ; 41(24): 3655-3662, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37179164

RESUMO

OBJECTIVES: Pneumococcal immunization is recommended in dialysis patients. We aimed to estimate pneumococcal vaccination coverage among patients who initiate dialysis in France, and its association with mortality. METHODS: Data were extracted from two prospective national databases, merged using a deterministic linkage method: renal epidemiology and information network (REIN) registry, which includes all patients on dialysis and kidney transplants recipients in France, and the national health insurance information system (SNIIRAM) which collects individual data on health expenditure reimbursement, including vaccines. We enrolled all patients who initiated chronic dialysis in 2015. Data on health status at dialysis initiation, dialysis modalities, and pneumococcal vaccine prescribed from 2 years before to 1 year after dialysis start were collected. Univariate and multivariate Cox proportional hazard models were used to assess one-year all-cause mortality. RESULTS: Among the 8,294 incident patients included, 1,849 (22.3 %) received at least one pneumococcal vaccine before (n = 542, 6.5 %), or after (n = 1,307, 15.8 %) dialysis start, as follows: 13-valent pneumococcal conjugated vaccine (PCV13) followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23), n = 938 (50.7 %); only PPSV23, n = 650 (35.1 %); or only PCV13, n = 261 (14.1 %). Vaccinated patients were younger (mean, 66.5 ± 14.8 years vs. 69.0 ± 14.9 years, P ≤ 0.001), more likely to suffer from glomerulonephritis (17.0 % vs. 11.0 %, P ≤ 0.001), and less likely to start dialysis in emergency (27.2 % vs. 31.1 %, P = 0.001). On multivariate analysis, patients who received PCV13 and PPSV23, or only PCV13 were less likely to die (respectively, HR = 0.37; 95 %CI 0.28-0.51, and HR = 0.35; 95 %CI 0.19-0.65). CONCLUSIONS: Pneumococcal immunization with PCV13 followed by PPSV23, or with PCV13 alone, but not with PPSV23 alone, is independently associated with decreased one year-mortality in patients who start dialysis.


Assuntos
Infecções Pneumocócicas , Humanos , Infecções Pneumocócicas/prevenção & controle , Cobertura Vacinal , Estudos Prospectivos , Vacinas Conjugadas , Diálise Renal , Streptococcus pneumoniae , Vacinação , Vacinas Pneumocócicas
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