RESUMEN
Eukaryotes have evolved multiple ATP-dependent chromatin remodelers to shape the nucleosome landscape. We recently uncovered an evolutionarily conserved SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeler complex in plants reminiscent of the mammalian BAF subclass, which specifically incorporates the MINUSCULE (MINU) catalytic subunits and the TRIPLE PHD FINGERS (TPF) signature subunits. Here we report experimental evidence that establishes the functional relevance of TPF proteins for the complex activity. Our results show that depletion of TPF triggers similar pleiotropic phenotypes and molecular defects to those found in minu mutants. Moreover, we report the genomic location of MINU2 and TPF proteins as representative members of this SWI/SNF complex and their impact on nucleosome positioning and transcription. These analyses unravel the binding of the complex to thousands of genes where it modulates the position of the +1 nucleosome. These targets tend to produce 5'-shifted transcripts in the tpf and minu mutants pointing to the participation of the complex in alternative transcription start site usage. Interestingly, there is a remarkable correlation between +1 nucleosome shift and 5' transcript length change suggesting their functional connection. In summary, this study unravels the function of a plant SWI/SNF complex involved in +1 nucleosome positioning and transcription start site determination.
Asunto(s)
Arabidopsis , Proteínas Cromosómicas no Histona , Nucleosomas , Sitio de Iniciación de la Transcripción , Adenosina Trifosfato/metabolismo , Animales , Arabidopsis/genética , Arabidopsis/metabolismo , Cromatina , Proteínas Cromosómicas no Histona/genética , Proteínas Cromosómicas no Histona/metabolismo , Mamíferos/genética , Nucleosomas/genética , Dedos de Zinc PHD , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Posttranslational modifications (PTMs), particularly phosphorylation, play a pivotal role in expanding the complexity of the proteome and regulating diverse cellular processes. In this study, we present an efficient Escherichia coli phosphorylation system designed to streamline the evaluation of potential substrates for Arabidopsis thaliana plant kinases, although the technology is amenable to any. The methodology involves the use of IPTG-inducible vectors for co-expressing kinases and substrates, eliminating the need for radioactive isotopes and prior protein purification. We validated the system's efficacy by assessing the phosphorylation of well-established substrates of the plant kinase SnRK1, including the rat ACETYL-COA CARBOXYLASE 1 (ACC1) and FYVE1/FREE1 proteins. The results demonstrated the specificity and reliability of the system in studying kinase-substrate interactions. Furthermore, we applied the system to investigate the phosphorylation cascade involving the A. thaliana MKK3-MPK2 kinase module. The activation of MPK2 by MKK3 was demonstrated to phosphorylate the Myelin Basic Protein (MBP), confirming the system's ability to unravel sequential enzymatic steps in phosphorylation cascades. Overall, this E. coli phosphorylation system offers a rapid, cost-effective, and reliable approach for screening potential kinase substrates, presenting a valuable tool to complement the current portfolio of molecular techniques for advancing our understanding of kinase functions and their roles in cellular signaling pathways.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Animales , Ratas , Fosforilación , Escherichia coli/genética , Reproducibilidad de los Resultados , Procesamiento Proteico-Postraduccional , Proteínas Serina-Treonina Quinasas , Proteínas de Transporte VesicularRESUMEN
We report data from a prospective, observational study (ZAGAL) evaluating miglustat 100mg three times daily orally. in treatment-naïve patients and patients with type 1 Gaucher Disease (GD1) switched from previous enzyme replacement therapy (ERT). Clinical evolution, changes in organ size, blood counts, disease biomarkers, bone marrow infiltration (S-MRI), bone mineral density by broadband ultrasound densitometry (BMD), safety and tolerability annual reports were analysed. Between May 2004 and April 2016, 63 patients received miglustat therapy; 20 (32%) untreated and 43 (68%) switched. At the time of this report 39 patients (14 [36%] treatment-naïve; 25 [64%] switch) remain on miglustat. With over 12-year follow-up, hematologic counts, liver and spleen volumes remained stable. In total, 80% of patients achieved current GD1 therapeutic goals. Plasma chitotriosidase activity and CCL-18/PARC concentration showed a trend towards a slight increase. Reductions on S-MRI (p=0.042) with an increase in BMD (p<0.01) were registered. Gastrointestinal disturbances were reported in 25/63 (40%), causing miglustat suspension in 11/63 (17.5%) cases. Thirty-eight patients (60%) experienced a fine hand tremor and two a reversible peripheral neuropathy. Overall, miglustat was effective as a long-term therapy in mild to moderate naïve and ERT stabilized patients. No unexpected safety signals were identified during 12-years follow-up.
Asunto(s)
1-Desoxinojirimicina/análogos & derivados , Enfermedad de Gaucher/tratamiento farmacológico , Inhibidores de Glicósido Hidrolasas/uso terapéutico , 1-Desoxinojirimicina/administración & dosificación , 1-Desoxinojirimicina/efectos adversos , 1-Desoxinojirimicina/uso terapéutico , Adolescente , Adulto , Anciano , Femenino , Estudios de Seguimiento , Enfermedad de Gaucher/sangre , Enfermedad de Gaucher/patología , Inhibidores de Glicósido Hidrolasas/administración & dosificación , Inhibidores de Glicósido Hidrolasas/efectos adversos , Humanos , Hígado/efectos de los fármacos , Hígado/patología , Masculino , Persona de Mediana Edad , Tamaño de los Órganos/efectos de los fármacos , Estudios Prospectivos , Bazo/efectos de los fármacos , Bazo/patología , Adulto JovenRESUMEN
Background. Fresh vegetables such as tomato should have low microbial population for safe consumption and long storage life. The aerobic bacterial count (ABC) and coliform bacterial count (CBC), yeast, and mold population are the most widely used microbial indicators in fresh vegetables which should be lower than 4 log CFU g-1 for safe consumption. The stages of the supply chain, postharvest handling methods, and crop varieties had significant effects on microbial population. ABC, CBC, yeast, and mold population were significantly highest (P < 0.05) at retail market (5.59, 4.38, 2.60, and 3.14 log CFU g-1, resp.), followed by wholesale market (4.72, 4.71, 2.43, and 2.44 log CFU g-1, resp.), and were least at farm gate (3.89, 3.63, 2.38, and 2.03 log CFU g-1, resp.). Improved postharvest practices (washing in clean water and grading and packaging in clean plastic crate) helped to reduce ABC, CBC, and mold population by 2.51, 32.70, and 29.86 percentage as compared to the conventional method (no washing and no grading and packaging in mud plastered bamboo baskets). Among varieties, Pusa ruby had the lowest microbial load of 2.58, 4.53, 0.96, and 1.77 log CFU g-1 for ABC, CBC, yeast, and mold count, respectively. Significantly negative correlation (P < 0.05) was observed between fruit pH & ABC and pH & mold count. Although the microbial quality of fresh tomato is safe in the local market of western Terai of Nepal both in conventional and in improved practices however still it is essential to follow improved postharvest handling practices in production and marketing of newly introduced tomato cultivars (high-pH cultivars) for ensuring the safe availability of fresh tomato in the market.
Asunto(s)
Manipulación de Alimentos/métodos , Microbiología de Alimentos , Solanum lycopersicum/crecimiento & desarrollo , Solanum lycopersicum/microbiología , Jugos de Frutas y Vegetales/microbiología , Concentración de Iones de Hidrógeno , Nepal , TransportesRESUMEN
In a prospective, open-label study, 25 patients with mild-to-moderate type 1 Gaucher's disease (GD1) were treated with miglustat (Zavesca), an oral glucosylceramide synthase inhibitor, over 12 months. Of the 25 patients, 10 were therapy-naïve and 15 had previously received enzyme replacement therapy (ERT). Clinical status, blood parameters, biomarkers, and organomegaly were assessed at baseline at 6 months and at 12 months. At 6 months the previously untreated patients showed a mean increase in hemoglobin of 0.77 g/dL, platelet counts improved or remaining stable, chitotriosidase and CCL18 decreased. These results were similar to those observed in 40 Spanish GD1 patients on ERT. Bone marrow infiltration cleared at 12 months. In the previously treated group, clinical and hematologic parameters and biomarkers were maintained/ improved at 12 months. Miglustat was well tolerated. The efficacy of miglustat treatment after 6 months was comparable to that of ERT.