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1.
Lucas Henriques Viscardi Danilo Oliveira Imparato Maria Ctira Bortolini Rodrigo Juliani Siqueira Dalmolin 《Molecular biology and evolution》2021,38(3):735
The origin of nervous systems is a main theme in biology and its mechanisms are largely underlied by synaptic neurotransmission. One problem to explain synapse establishment is that synaptic orthologs are present in multiple aneural organisms. We questioned how the interactions among these elements evolved and to what extent it relates to our understanding of the nervous systems complexity. We identified the human neurotransmission gene network based on genes present in GABAergic, glutamatergic, serotonergic, dopaminergic, and cholinergic systems. The network comprises 321 human genes, 83 of which act exclusively in the nervous system. We reconstructed the evolutionary scenario of synapse emergence by looking for synaptic orthologs in 476 eukaryotes. The Human–Cnidaria common ancestor displayed a massive emergence of neuroexclusive genes, mainly ionotropic receptors, which might have been crucial to the evolution of synapses. Very few synaptic genes had their origin after the Human–Cnidaria common ancestor. We also identified a higher abundance of synaptic proteins in vertebrates, which suggests an increase in the synaptic network complexity of those organisms. 相似文献
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William T. Scott David Henriques Eddy J. Smid Richard A. Notebaart Eva Balsa-Canto 《Biotechnology and bioengineering》2023,120(7):1998-2012
Fermentation employing Saccharomyces cerevisiae has produced alcoholic beverages and bread for millennia. More recently, S. cerevisiae has been used to manufacture specific metabolites for the food, pharmaceutical, and cosmetic industries. Among the most important of these metabolites are compounds associated with desirable aromas and flavors, including higher alcohols and esters. Although the physiology of yeast has been well-studied, its metabolic modulation leading to aroma production in relevant industrial scenarios such as winemaking is still unclear. Here we ask what are the underlying metabolic mechanisms that explain the conserved and varying behavior of different yeasts regarding aroma formation under enological conditions? We employed dynamic flux balance analysis (dFBA) to answer this key question using the latest genome-scale metabolic model (GEM) of S. cerevisiae. The model revealed several conserved mechanisms among wine yeasts, for example, acetate ester formation is dependent on intracellular metabolic acetyl-CoA/CoA levels, and the formation of ethyl esters facilitates the removal of toxic fatty acids from cells using CoA. Species-specific mechanisms were also found, such as a preference for the shikimate pathway leading to more 2-phenylethanol production in the Opale strain as well as strain behavior varying notably during the carbohydrate accumulation phase and carbohydrate accumulation inducing redox restrictions during a later cell growth phase for strain Uvaferm. In conclusion, our new metabolic model of yeast under enological conditions revealed key metabolic mechanisms in wine yeasts, which will aid future research strategies to optimize their behavior in industrial settings. 相似文献
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Assembly and interactions of cotJ-encoded proteins, constituents of the inner layers of the Bacillus subtilis spore coat 总被引:2,自引:0,他引:2
Richard W. Seyler Jr Adriano O. Henriques Amanda J. Ozin & Charles P. Moran Jr 《Molecular microbiology》1997,25(5):955-966
During Bacillus subtilis endospore formation, a complex protein coat is assembled around the maturing spore. The coat is made up of more than two dozen proteins that form an outer layer, which provides chemical resistance, and an inner layer, which may play a role in the activation of germination. A third, amorphous layer of the coat occupies the space between the inner coat and the cortex, and is referred to as the undercoat. Although several coat proteins have been characterized, little is known about their interactions during assembly of the coat. We show here that at least two open reading frames of the cotJ operon ( cotJA and cotJC ) encode spore coat proteins. We suggest that CotJC is a component of the undercoat, since we found that its assembly onto the forespore is not prevented by mutations that block both inner and outer coat assembly, and because CotJC is more accessible to antibody staining in spores lacking both of these coat layers. Assembly of CotJC into the coat is dependent upon expression of cotJA . Conversely, CotJA is not detected in the coats of a cotJC insertional mutant. Co-immunoprecipitation was used to demonstrate the formation of complexes containing CotJA and CotJC 6 h after the onset of sporulation. Experiments with the yeast two-hybrid system indicate that CotJC may interact with itself and with CotJA. We suggest that interaction of CotJA with CotJC is required for the assembly of both CotJA and CotJC into the spore coat. 相似文献
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Washed chloroplast membranes from romaine lettuce leaves were treated with the cross-linking reagent dimethyladipimidate (DMA) for various periods of time and subsequently analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Comparative examination of the electrophoretic profiles from control and treated membranes revealed that the light-harvesting chlorophyll-protein complex (LHCPC) was readily cross-linked to yield “dimers” and “oligomers” of higher molecular weight. Two polypeptides, of 25 and 23 kilodaltons, previously identified as two subunits of the LHCPC, were the major cross-linked species; other peptides were also cross-linked, but to a much lesser extent. These results suggest that cross-linking of chloroplast membranes with DMA, under our conditions, occurs primarily among the components of the LHCPC. We also measured the photosystem II activity in control and DMA-treated chloroplasts and found no impairment of this photochemical activity in the cross-linked chloroplasts as compared with controls. 相似文献
7.
E J Van Zoelen C Henriques de Jesus E de Jonge M Mulder M C Blok J de Gier 《Biochimica et biophysica acta》1978,511(3):335-347
1. The reflection coefficient for the permeation of thiourea through bilayers of phosphatidylcholine is a function of the fatty-acid composition of the lipid molecules. By means of these reflection coefficients an index for membrane fluidity has been given to each of those lipids, relative to that of egg phosphatidylcholine. 2. The maximum number of water molecules that can copermeate with each molecule of solute by means of solute-solvent interaction is a function of the packing of the lipid molecules in the bilayer. This parameter has been used in this paper for characterizing the fluidity of cholesterol-containing membranes and for membranes with their lipids in the gel state. 相似文献
8.
In the present study we extend previous work from this laboratory on the polypeptide composition of photosynthetic lamellae. Using a high resolution sodium dodecyl sulfate gel electrophoresis technique, we show that both grana and stroma lamellae have qualitatively very similar polypeptide compositions although some clear quantitative differences are demonstrated. 相似文献
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Marking of sited cells after electrophysiologic study 总被引:1,自引:0,他引:1