| 11. |
- Chen, Changchun, et al.
(författare)
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IL-17 is a neuromodulator of Caenorhabditis elegans sensory responses
- 2017
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Ingår i: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 542:7639, s. 43-48
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Tidskriftsartikel (refereegranskat)abstract
- Interleukin-17 (IL-17) is a major pro-inflammatory cytokine: it mediates responses to pathogens or tissue damage, and drives autoimmune diseases. Little is known about its role in the nervous system. Here we show that IL-17 has neuromodulator-like properties in Caenorhabditis elegans. IL-17 can act directly on neurons to alter their response properties and contribution to behaviour. Using unbiased genetic screens, we delineate an IL-17 signalling pathway and show that it acts in the RMG hub interneurons. Disrupting IL-17 signalling reduces RMG responsiveness to input from oxygen sensors, and renders sustained escape from 21% oxygen transient and contingent on additional stimuli. Over-activating IL-17 receptors abnormally heightens responses to 21% oxygen in RMG neurons and whole animals. IL-17 deficiency can be bypassed by optogenetic stimulation of RMG. Inducing IL-17 expression in adults can rescue mutant defects within 6 h. These findings reveal a non-immunological role of IL-17 modulating circuit function and behaviour.
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| 12. |
- de lavergne, C., et al.
(författare)
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Abyssal ocean overturning shaped by seafloor distribution
- 2017
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 551:7679, s. 181-186
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Tidskriftsartikel (refereegranskat)abstract
- The abyssal ocean is broadly characterized by northward flow of the densest waters and southward flow of less-dense waters above them. Understanding what controls the strength and structure of these interhemispheric flows-referred to as the abyssal overturning circulation-is key to quantifying the ocean's ability to store carbon and heat on timescales exceeding a century. Here we show that, north of 32 degrees S, the depth distribution of the seafloor compels dense southernorigin waters to flow northward below a depth of about 4 kilometres and to return southward predominantly at depths greater than 2.5 kilometres. Unless ventilated from the north, the overlying mid-depths (1 to 2.5 kilometres deep) host comparatively weak mean meridional flow. Backed by analysis of historical radiocarbon measurements, the findings imply that the geometry of the Pacific, Indian and Atlantic basins places a major external constraint on the overturning structure.
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| 13. |
- Elmqvist, Thomas
(författare)
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Sustainability and resilience differ
- 2017
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 546:7658, s. 352-352
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 14. |
- Elsasser, SJ, et al.
(författare)
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Elsässer et al. reply
- 2017
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 548:7665, s. E7-E12
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Tidskriftsartikel (refereegranskat)
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| 15. |
- Ernberg, I, et al.
(författare)
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George Klein (1925-2016)
- 2017
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 542:7641, s. 296-296
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Tidskriftsartikel (refereegranskat)
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| 16. |
- Figueres, Christiana, et al.
(författare)
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Three years to safeguard our climate
- 2017
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 546:7660, s. 593-595
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 17. |
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| 18. |
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| 19. |
- Grilli, Jacopo, et al.
(författare)
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Higher-order interactions stabilize dynamics in competitive network models
- 2017
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Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 548:7666, s. 210-
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Tidskriftsartikel (refereegranskat)abstract
- Ecologists have long sought a way to explain how the remarkable biodiversity observed in nature is maintained. On the one hand, simple models of interacting competitors cannot produce the stable persistence of very large ecological communities(1-5). On the other hand, neutral models(6-9), in which species do not interact and diversity is maintained by immigration and speciation, yield unrealistically small fluctuations in population abundance(10), and a strong positive correlation between a species' abundance and its age(11), contrary to empirical evidence. Models allowing for the robust persistence of large communities of interacting competitors are lacking. Here we show that very diverse communities could persist thanks to the stabilizing role of higher-order interactions(12,13), in which the presence of a species influences the interaction between other species. Although higher-order interactions have been studied for decades(14-16), their role in shaping ecological communities is still unclear(5). The inclusion of higher-order interactions in competitive network models stabilizes dynamics, making species coexistence robust to the perturbation of both population abundance and parameter values. We show that higher-order interactions have strong effects in models of closed ecological communities, as well as of open communities in which new species are constantly introduced. In our framework, higher-order interactions are completely defined by pairwise interactions, facilitating empirical parameterization and validation of our models.
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| 20. |
- Gupta, Kallol, et al.
(författare)
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The role of interfacial lipids in stabilizing membrane protein oligomers
- 2017
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 541:7637, s. 421-424
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Tidskriftsartikel (refereegranskat)abstract
- Oligomerization of membrane proteins in response to lipid binding has a critical role in many cell-signalling pathways(1) but is often difficult to define(2) or predict(3). Here we report the development of a mass spectrometry platform to determine simultaneously the presence of interfacial lipids and oligomeric stability and to uncover how lipids act as key regulators of membrane-protein association. Evaluation of oligomeric strength for a dataset of 125 alpha-helical oligomeric membrane proteins reveals an absence of interfacial lipids in the mass spectra of 12 membrane proteins with high oligomeric stability. For the bacterial homologue of the eukaryotic biogenic transporters (LeuT(4), one of the proteins with the lowest oligomeric stability), we found a precise cohort of lipids within the dimer interface. Delipidation, mutation of lipid-binding sites or expression in cardiolipin-deficient Escherichia coli abrogated dimer formation. Molecular dynamics simulation revealed that cardiolipin acts as a bidentate ligand, bridging across subunits. Subsequently, we show that for the Vibrio splendidus sugar transporter SemiSWEET(5), another protein with low oligomeric stability, cardiolipin shifts the equilibrium from monomer to functional dimer. We hypothesized that lipids are essential for dimerization of the Na+/H+ antiporter NhaA from E. coli, which has the lowest oligomeric strength, but not for the substantially more stable homologous Thermus thermophilus protein NapA. We found that lipid binding is obligatory for dimerization of NhaA, whereas NapA has adapted to form an interface that is stable without lipids. Overall, by correlating interfacial strength with the presence of interfacial lipids, we provide a rationale for understanding the role of lipids in both transient and stable interactions within a range of a-helical membrane proteins, including G-protein-coupled receptors.
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