排序方式: 共有167条查询结果,搜索用时 656 毫秒
91.
Shamsi Emtenani Elliot T Martin Attila Gyoergy Julia Bicher JakobWendelin Genger Thomas Kcher Maria Akhmanova Mariana Guarda Marko Roblek Andreas Bergthaler Thomas R Hurd Prashanth Rangan Daria E Siekhaus 《The EMBO journal》2022,41(12)
Cellular metabolism must adapt to changing demands to enable homeostasis. During immune responses or cancer metastasis, cells leading migration into challenging environments require an energy boost, but what controls this capacity is unclear. Here, we study a previously uncharacterized nuclear protein, Atossa (encoded by CG9005), which supports macrophage invasion into the germband of Drosophila by controlling cellular metabolism. First, nuclear Atossa increases mRNA levels of Porthos, a DEAD‐box protein, and of two metabolic enzymes, lysine‐α‐ketoglutarate reductase (LKR/SDH) and NADPH glyoxylate reductase (GR/HPR), thus enhancing mitochondrial bioenergetics. Then Porthos supports ribosome assembly and thereby raises the translational efficiency of a subset of mRNAs, including those affecting mitochondrial functions, the electron transport chain, and metabolism. Mitochondrial respiration measurements, metabolomics, and live imaging indicate that Atossa and Porthos power up OxPhos and energy production to promote the forging of a path into tissues by leading macrophages. Since many crucial physiological responses require increases in mitochondrial energy output, this previously undescribed genetic program may modulate a wide range of cellular behaviors. 相似文献
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Research over the past few decades has attempted to answer how proteins behave in molecularly confined or crowded environments when compared to dilute buffer solutions. This information is vital to understanding in vivo protein behavior, as the average spacing between macromolecules in the cell cytosol is much smaller than the size of the macromolecules themselves. In our study, we attempt to address this question using three structurally and functionally different model enzymes encapsulated in agarose gels of different porosities. Our studies reveal that under standard buffer conditions, the initial reaction rates of the agarose-encapsulated enzymes are lower than that of the solution phase enzymes. However, the encapsulated enzymes retain a higher percentage of their activity in the presence of denaturants. Moreover, the concentration of agarose used for encapsulation had a significant effect on the enzyme functional stability; enzymes encapsulated in higher percentages of agarose were more stable than the enzymes encapsulated in lower percentages of agarose. Similar results were observed through structural measurements of enzyme denaturation using an 8-anilinonaphthalene-1-sulfonic acid fluorescence assay. Our work demonstrates the utility of hydrogels to study protein behavior in highly confined environments similar to those present in vivo; furthermore, the enhanced stability of gel-encapsulated enzymes may find use in the delivery of therapeutic proteins, as well as the design of novel strategies for biohybrid medical devices. 相似文献
93.
The torsional potential functions Vt(phi) and Vt(psi) around single bonds N--C alpha and C alpha--C, which can be used in conformational studies of oligopeptides, polypeptides and proteins, have been derived, using crystal structure data of 22 globular proteins, fitting the observed distribution in the (phi, psi)-plane with the value of Vtot(phi, psi), using the Boltzmann distribution. The averaged torsional potential functions, obtained from various amino acid residues in L-configuration, are Vt(phi) = 1.0 cos (phi + 60 degrees); Vt(psi) = 0.5 cos (psi + 60 degrees) - 1.0 cos (2 psi + 30 degrees) - 0.5 cos (3 psi + 30 degrees). The dipeptide energy maps Vtot(phi, psi) obtained using these functions, instead of the normally accepted torsional functions, were found to explain various observations, such as the absence of the left-handed alpha helix and the C7 conformation, and the relatively high density of points near the line psi = 0 degrees. These functions derived from observational data on protein structures, will, it is hoped, explain various previously unexplained facts in polypeptide conformation. 相似文献
94.
Hypothetical protein [HP] annotation poses a great challenge especially when the protein is putatively linked or mapped to another protein. With protein interaction networks (PIN) prevailing, many visualizers still remain unsupported to the HP annotation. Through this work, we propose a six-point classification system to validate protein interactions based on diverse features. The HP data-set was used as a training data-set to find putative functional interaction partners to the remaining proteins that are waiting to be interacting. A Total Reliability Score (TRS) was calculated based on the six-point classification which was evaluated using machine learning algorithm on a single node. We found that multilayer perceptron of neural network yielded 81.08% of accuracy in modelling TRS whereas feature selection algorithms confirmed that all classification features are implementable. Furthermore statistical results using variance and co-variance analyses confirmed the usefulness of these classification metrics. It has been evaluated that of all the classification features, subcellular location (sorting signals) makes higher impact in predicting the function of HPs. 相似文献
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Mewa Singh Tephillah Jeyaraj U. Prashanth Werner Kaumanns 《International journal of primatology》2011,32(1):167-176
Socioecology suggests that female distribution in space is determined by the distribution of food resources and the male distribution
is influenced by female distribution. Though studies have traditionally focused on females, males have received increasing
attention in recent years. We compared male–male relationships in lion-tailed macaques and bonnet macaques. Because bonnet
macaques have a high adult male:female sex ratio and are seasonal breeders whereas lion-tailed macaques have a low adult male:female
sex ratio and are largely aseasonal breeders, we predicted that bonnet macaque males would be spatially and socially more
tolerant of each other and would have less linear dominance relationships than lion-tailed macaques. We recorded male–male
and male–female relationships in 1 group of wild macaques of each species via scan sampling and 1–0 sampling. The results
revealed that lion-tailed macaque males largely remained at a distance from each other whereas bonnet macaque males remained
in close proximity to one another. Lion-tailed macaque males were more agonistic toward each other whereas bonnet macaque
males showed more affiliative interactions. The dominance hierarchy among lion-tailed macaque males was more linear than among
bonnet macaque males. Our data support the hypothesis that the study of spatial structuring, temporality of interactions,
and linearity of social relationships may contribute to a better understanding of macaque social systems. 相似文献
97.
Bhargavi M. Maneesha K. Withanawasam D. M. Aratikatla Kavitha R. Himabindu S. Prashanth M. Shanthi P. Kommana Madhavi L. Reddy D. Mohan Reddy B. Ravindra Vemireddy Lakshminarayana R. 《Molecular biology reports》2021,48(3):2209-2221
Molecular Biology Reports - Rice varietal identification is a crucial aspect in breeding, seed production and trade in order to protect the interests of the farmers and consumers. As the number of... 相似文献
98.
Prashanth Selvaraj Jamie W. Sleigh Walter J. Freeman Heidi E. Kirsch Andrew J. Szeri 《Journal of computational neuroscience》2014,36(3):515-525
We present a model for the use of open loop optogenetic control to inhibit epileptiform activity in a meso scale model of the human cortex. The meso scale cortical model first developed by Liley et al. (2001) is extended to two dimensions and the nature of the seizure waves is studied. We adapt to the meso scale a 4 state functional model of Channelrhodopsin-2 (ChR2) ion channels. The effects of pulsed and constant illumination on the conductance of these ion channels is presented. The inhibitory cell population is targeted for the application of open loop control. Seizure waves are successfully suppressed and the inherent properties of the optogenetic channels ensures charge balance in the cortex, protecting it from damage. 相似文献
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Prashanth Bhaganna Rita J. M. Volkers Andrew N. W. Bell Kathrin Kluge David J. Timson John W. McGrath Harald J. Ruijssenaars John E. Hallsworth 《Microbial biotechnology》2010,3(6):701-716
Ubiquitous noxious hydrophobic substances, such as hydrocarbons, pesticides and diverse industrial chemicals, stress biological systems and thereby affect their ability to mediate biosphere functions like element and energy cycling vital to biosphere health. Such chemically diverse compounds may have distinct toxic activities for cellular systems; they may also share a common mechanism of stress induction mediated by their hydrophobicity. We hypothesized that the stressful effects of, and cellular adaptations to, hydrophobic stressors operate at the level of water : macromolecule interactions. Here, we present evidence that: (i) hydrocarbons reduce structural interactions within and between cellular macromolecules, (ii) organic compatible solutes – metabolites that protect against osmotic and chaotrope-induced stresses – ameliorate this effect, (iii) toxic hydrophobic substances induce a potent form of water stress in macromolecular and cellular systems, and (iv) the stress mechanism of, and cellular responses to, hydrophobic substances are remarkably similar to those associated with chaotrope-induced water stress. These findings suggest that it may be possible to devise new interventions for microbial processes in both natural environments and industrial reactors to expand microbial tolerance of hydrophobic substances, and hence the biotic windows for such processes. 相似文献