Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Insects ; 13(1)2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-35055892

RESUMEN

Oedaleus decorus is a widely distributed acridid over the Eurasian semi-arid territories, from the Atlantic coast to the Pacific coast. In many semi-arid territories, O. decorus was and is the most important pest, but in the south-eastern part of West Siberian Plain, it was not considered a pest until the 1960s. We compared two sets of data on the acridid distribution in the region: before 1960 and from 1961 until 2021. Until the 1960s, the species occurred mainly in the southern steppes. Since the 1960s, its distribution changed significantly. Nowadays, it occupies almost all local steppes and the southern part of the forest-steppes and can be also found on the eastern side of the Ob River. These shifts may be explained by both climatic changes and changes in human activities. During upsurges the densities of O. decorus were often more than one to two adults per square meter. It is often abundant in the same habitats and in the same periods as the Italian locust (Calliptamus italicus)-one of the most important acridid pests. This means during joint outbreaks these two species can simultaneously damage almost all spectrum of plants.

2.
Nucleic Acids Res ; 49(8): 4705-4724, 2021 05 07.
Artículo en Inglés | MEDLINE | ID: mdl-33849070

RESUMEN

Antisense peptide nucleic acids (PNAs) inhibiting mRNAs of essential genes provide a straight-forward way to repurpose our knowledge of bacterial regulatory RNAs for development of programmable species-specific antibiotics. While there is ample proof of PNA efficacy, their target selectivity and impact on bacterial physiology are poorly understood. Moreover, while antibacterial PNAs are typically designed to block mRNA translation, effects on target mRNA levels are not well-investigated. Here, we pioneer the use of global RNA-seq analysis to decipher PNA activity in a transcriptome-wide manner. We find that PNA-based antisense oligomer conjugates robustly decrease mRNA levels of the widely-used target gene, acpP, in Salmonella enterica, with limited off-target effects. Systematic analysis of several different PNA-carrier peptides attached not only shows different bactericidal efficiency, but also activation of stress pathways. In particular, KFF-, RXR- and Tat-PNA conjugates especially induce the PhoP/Q response, whereas the latter two additionally trigger several distinct pathways. We show that constitutive activation of the PhoP/Q response can lead to Tat-PNA resistance, illustrating the utility of RNA-seq for understanding PNA antibacterial activity. In sum, our study establishes an experimental framework for the design and assessment of PNA antimicrobials in the long-term quest to use these for precision editing of microbiota.


Asunto(s)
Oligonucleótidos Antisentido/farmacología , Ácidos Nucleicos de Péptidos/farmacología , Péptidos/química , ARN Mensajero/metabolismo , Salmonella enterica/efectos de los fármacos , Estrés Fisiológico/genética , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Proliferación Celular/efectos de los fármacos , Proliferación Celular/genética , Farmacorresistencia Bacteriana/genética , Pruebas de Sensibilidad Microbiana , Oligopéptidos/farmacología , Fragmentos de Péptidos/farmacología , Ácidos Nucleicos de Péptidos/metabolismo , Péptidos/metabolismo , Péptidos/farmacología , Estabilidad del ARN/efectos de los fármacos , ARN Mensajero/genética , RNA-Seq , Salmonella enterica/genética , Salmonella enterica/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/farmacología
3.
Cell ; 157(4): 922-934, 2014 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-24813614

RESUMEN

The GroEL/ES chaperonin system functions as a protein folding cage. Many obligate substrates of GroEL share the (ßα)8 TIM-barrel fold, but how the chaperonin promotes folding of these proteins is not known. Here, we analyzed the folding of DapA at peptide resolution using hydrogen/deuterium exchange and mass spectrometry. During spontaneous folding, all elements of the DapA TIM barrel acquire structure simultaneously in a process associated with a long search time. In contrast, GroEL/ES accelerates folding more than 30-fold by catalyzing segmental structure formation in the TIM barrel. Segmental structure formation is also observed during the fast spontaneous folding of a structural homolog of DapA from a bacterium that lacks GroEL/ES. Thus, chaperonin independence correlates with folding properties otherwise enforced by protein confinement in the GroEL/ES cage. We suggest that folding catalysis by GroEL/ES is required by a set of proteins to reach native state at a biologically relevant timescale, avoiding aggregation or degradation.


Asunto(s)
Chaperonina 10/metabolismo , Chaperonina 60/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Pliegue de Proteína , Secuencia de Aminoácidos , Catálisis , Medición de Intercambio de Deuterio , Escherichia coli/química , Escherichia coli/enzimología , Hidroliasas/química , Hidroliasas/metabolismo , Espectrometría de Masas , Modelos Moleculares , Datos de Secuencia Molecular , Mycoplasma synoviae/enzimología , Mycoplasma synoviae/metabolismo , Oxo-Ácido-Liasas/química , Oxo-Ácido-Liasas/metabolismo , Estructura Terciaria de Proteína
4.
Arch Biochem Biophys ; 516(1): 75-83, 2011 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-21995946

RESUMEN

The cytosolic chaperonin TRiC was isolated from ovine testes using ultracentrifugation and heparin-Sepharose chromatography. The molecular mass of the obtained preparation was shown to exceed 900 kDa (by Blue Native PAGE). SDS-PAGE yielded a set of bands in the range of 50-60 kDa. Electron microscopy examination revealed ring-shaped complexes with the outer diameter of 15 nm and the inner diameter of approximately 6 nm. The results suggest that the purified chaperonin is an oligomeric complex composed of two 8-membered rings. The chaperonin TRiC was shown to assist an ATP-dependent refolding of recombinant forms of sperm-specific glyceraldehyde-3-phosphate dehydrogenase, an enzyme that is expressed only in precursor cells of the sperms in the seminiferous tubules of the testes. In contrast, TRiC did not influence the refolding of muscle isoform of glyceraldehyde-3-phosphate dehydrogenase and assisted the refolding of muscle lactate dehydrogenase by an ATP-independent mechanism. The obtained results suggest that TRiC is likely to be involved in the refolding of sperm-specific proteins.


Asunto(s)
Chaperoninas/metabolismo , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Espermatozoides/enzimología , Secuencia de Aminoácidos , Animales , Chaperoninas/química , Chaperoninas/genética , Chaperoninas/aislamiento & purificación , Humanos , Masculino , Datos de Secuencia Molecular , Pliegue de Proteína , Subunidades de Proteína/química , Subunidades de Proteína/genética , Subunidades de Proteína/aislamiento & purificación , Subunidades de Proteína/metabolismo , ARN Mensajero/análisis , ARN Mensajero/genética , Conejos , Alineación de Secuencia , Ovinos , Espermatozoides/metabolismo , Testículo/enzimología , Testículo/metabolismo
5.
J Bioenerg Biomembr ; 41(3): 239-49, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19609656

RESUMEN

In this study we used tightly-coupled mitochondria from Yarrowia lipolytica and Dipodascus (Endomyces) magnusii yeasts, possessing a respiratory chain with the usual three points of energy conservation. High-amplitude swelling and collapse of the membrane potential were used as parameters for demonstrating induction of the mitochondrial permeability transition due to opening of a pore (mPTP). Mitochondria from Y. lipolytica, lacking a natural mitochondrial Ca(2+) uptake pathway, and from D. magnusii, harboring a high-capacitive, regulated mitochondrial Ca(2+) transport system (Bazhenova et al. J Biol Chem 273:4372-4377, 1998a; Bazhenova et al. Biochim Biophys Acta 1371:96-100, 1998b; Deryabina and Zvyagilskaya Biochemistry (Moscow) 65:1352-1356, 2000; Deryabina et al. J Biol Chem 276:47801-47806, 2001) were very resistant to Ca(2+) overload. However, exposure of yeast mitochondria to 50-100 microM Ca(2+) in the presence of the Ca(2+) ionophore ETH129 induced collapse of the membrane potential, possibly due to activation of the fatty acid-dependent Ca(2+)/nH(+)-antiporter, with no classical mPTP induction. The absence of response in yeast mitochondria was not simply due to structural limitations, since large-amplitude swelling occurred in the presence of alamethicin, a hydrophobic, helical peptide, forming voltage-sensitive ion channels in lipid membranes. Ca(2+)- ETH129-induced activation of the Ca(2+)/H(+)-antiport system was inhibited and prevented by bovine serum albumin, and partially by inorganic phosphate and ATP. We subjected yeast mitochondria to other conditions known to induce the permeability transition in animal mitochondria, i.e., Ca(2+) overload (in the presence of ETH129) combined with palmitic acid (Mironova et al. J Bioenerg Biomembr 33:319-331, 2001; Sultan and Sokolove Arch Biochem Biophys 386:37-51, 2001), SH-reagents, carboxyatractyloside (an inhibitor of the ADP/ATP translocator), depletion of intramitochondrial adenine nucleotide pools, deenergization of mitochondria, and shifting to acidic pH values in the presence of high phosphate concentrations. None of the above-mentioned substances or conditions induced a mPTP-like pore. It is thus evident that the permeability transition in yeast mitochondria is not coupled with Ca(2+) uptake and is differently regulated compared to the mPTP of animal mitochondria.


Asunto(s)
Dipodascus/citología , Potenciales de la Membrana/fisiología , Membranas Mitocondriales/fisiología , Yarrowia/citología , Alameticina/farmacología , Antiportadores/metabolismo , Calcio/metabolismo , Calcio/farmacología , Proteínas de Transporte de Catión/metabolismo , Ciclohexanos/farmacología , Ionóforos/farmacología , Potenciales de la Membrana/efectos de los fármacos , Permeabilidad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...